CN102601281A

CN102601281A - Method for determining blanks of different thickness for local loading forming of three-dimensional frame-shaped member

Info

Publication number: CN102601281A
Application number: CN2012100461742A
Authority: CN
Inventors: 杨合; 张大伟; 樊晓光
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2012-02-28
Filing date: 2012-02-28
Publication date: 2012-07-25
Anticipated expiration: 2032-02-28
Also published as: CN102601281B

Abstract

Disclosed is a method for determining blanks of different thickness for local loading forming of a three-dimensional frame-shaped member. The method includes steps of determining a calculating formula for sizes of inflow ribbed cavity materials according to various loading states in a forming process to realize fast analysis of a simplified interface and shortening time for determining blank shapes, and modifying blank shapes according to numerical simulation results, and determining the blanks of different thickness which meet the filling demands so as to reduce cost. By the method, the determined size distribution of the blanks of different thickness is reasonable, the flaws such as insufficient filling, folding and the like in the forming process are eliminated, machining allowance and forming load are reduced, and the blanking is easy due to the simple blank shapes.

Description

Method for Determining Unequal Thickness Blanks for Partially Loaded Forming of 3D Frame Components

技术领域 technical field

本发明涉及热加工领域中的难变形合金的热加工锻造，具体是一种确定框形三维构件局部加载成形用不等厚坯料的方法。The invention relates to hot-working forging of hard-to-deform alloys in the field of hot-working, in particular to a method for determining blanks of unequal thickness for local loading and forming of frame-shaped three-dimensional components.

技术背景 technical background

采用高性能轻质合金材料，如钛合金，和轻量化结构，如薄壁、整体、带筋等结构，是提高零部件的性能和可靠性、实现装备轻量化的有效技术途径。具有高筋薄腹结构的大型筋板类整体构件，有效地提高了结构效率、减轻装备重量并有具有优异的服役性能，是航空航天飞行器中重要的轻量化承力构件。The use of high-performance lightweight alloy materials, such as titanium alloys, and lightweight structures, such as thin-walled, integral, and ribbed structures, is an effective technical way to improve the performance and reliability of parts and realize lightweight equipment. The large-scale rib-plate integral member with high-reinforcement and thin-web structure effectively improves structural efficiency, reduces equipment weight and has excellent service performance. It is an important lightweight load-bearing member in aerospace vehicles.

此类大型复杂构件不仅成形材料难变形而且构件结构复杂、投影面积大，采用传统塑性成形工艺整体成形这类构件需要巨型压力机，普遍超出现有设备能力。采用模具分区实现局部加载并结合等温锻造能够有效降低成形载荷、拓展设备能力。但是由于投影面积大以及结构复杂，其塑性成形过程中和容易出现折叠、充填不满等成形缺陷。一般地为了减少无益的材料流动，坯料在水平投影形状应当接近于锻件投影形状。同时为了保证型腔充填、避免成形缺陷，需要改变坯料厚度分布以获得初步的体积分配。Such large and complex components are not only difficult to deform, but also complex in structure and large in projected area. Using traditional plastic forming processes to integrally form such components requires a giant press, which generally exceeds the capabilities of existing equipment. The use of die partitions to realize partial loading combined with isothermal forging can effectively reduce the forming load and expand the equipment capacity. However, due to the large projected area and complex structure, forming defects such as folding and insufficient filling are prone to occur during the plastic forming process. Generally, in order to reduce unwanted material flow, the shape of the blank in horizontal projection should be close to that of the forging. At the same time, in order to ensure cavity filling and avoid forming defects, it is necessary to change the thickness distribution of the blank to obtain a preliminary volume distribution.

由于尺寸大、结构复杂、并具有极端尺寸配合特征，此类筋板类整体构件锻造成形全过程的基于数值模拟方法的正向模拟分析需要较长的计算时间。采用基于数值模拟方法的反向模拟以及正向模拟的预成形优化设计方法较为困难，并需要较长的计算时间，限制了此类方法的应用。对于筋板类构件，一般其预成形坯料形状类似于终锻件，往往是对终锻件筋的高、宽、圆角半径进行放缩来设计预成形坯料(T.阿尔坦等著，陆索译.现代锻造——设备、材料和工艺[M].北京：国防工业出版社，1982；J.C.Choi，B.M.Kim，S.W.Kim.Computer-aided design of blockers for rib-web type forging[J].Journal Materials Processing Technology，1995，54(1-4)：314-321)。采用以上这些方法获得的预成形坯料形状比较复杂，接近锻件形状，难以适用于大型复杂小批量筋板类整体构件的塑性成形。Due to the large size, complex structure, and extreme dimensional matching characteristics, the forward simulation analysis based on the numerical simulation method of the whole process of forging and forming of such ribs and plates requires a long calculation time. It is difficult to use the reverse simulation based on the numerical simulation method and the preform optimization design method based on the forward simulation, and it requires a long calculation time, which limits the application of such methods. For stiffened plate members, the shape of the preformed blank is generally similar to that of the final forging, and the height, width, and fillet radius of the final forging tendon are often scaled to design the preformed blank (T. Altan et al., translated by Lu Suo .Modern forging—equipment, material and process[M].Beijing: National Defense Industry Press, 1982; J.C.Choi, B.M.Kim, S.W.Kim.Computer-aided design of blockers for rib-web type forging[J].Journal Materials Processing Technology, 1995, 54(1-4): 314-321). The shape of the preformed blanks obtained by the above methods is relatively complex, close to the shape of forgings, and it is difficult to apply to the plastic forming of large-scale, complex and small-batch integral members such as ribs.

对于此类大型复杂构件，采用简单不等厚坯料能够降低成本、有效改善型腔充填。杨合等人(孙念光，杨合，孙志超.大型钛合金隔框等温闭式模锻成形工艺优化[J].稀有金属与工程，2009，38(7)：1296-1300；Z.C.Sun，H.Yang.Forming quality of titaniumalloy large-scale integral components isothermal local loading[J].The Arabian Journal forScience and Engineering，2009，34(1C)：35-45)根据充填效果将构件分为难成形区和易成形区，根据不同部分的材料体积设计坯料厚度，该不等厚坯料改善了型腔充填，但仍有部分区域明显未充满。张会等(张会，姚泽坤，戴亮，郭鸿镇.金属结构等温成形过程金属流动规律与充填性的物理模拟[J].航空制造技术，2007，(1)：73-76，91)应用物理模拟试验方法确定了“Z”型界面的钛合金筋板类构件整体加载锻造的不等厚坯料形状，但是没有考虑到模具分区的局部加载特征，而且实验方法周期长费用高，特别是对于大型筋板类整体构件，限制了此类方法的应用。For such large and complex components, the use of simple unequal-thickness blanks can reduce costs and effectively improve cavity filling. Yang He et al. (Sun Nianguang, Yang He, Sun Zhichao. Optimization of isothermal closed die forging process for large titanium alloy frame[J]. Rare Metals and Engineering, 2009, 38(7): 1296-1300; Z.C.Sun, H. Yang. Forming quality of titanium alloy large-scale integral components isothermal local loading[J]. The Arabian Journal for Science and Engineering, 2009, 34(1C): 35-45) according to the filling effect, the components are divided into difficult-to-form areas and easy-to-form areas. The thickness of the blank is designed according to the material volume of different parts. The unequal thickness of the blank improves the filling of the cavity, but there are still some areas that are obviously not filled. Zhang Hui et al. (Zhang Hui, Yao Zekun, Dai Liang, Guo Hongzhen. Physical Simulation of Metal Flow and Filling During Isothermal Forming of Metal Structures [J]. Aviation Manufacturing Technology, 2007, (1): 73-76, 91) Applied Physics The simulation test method determines the shape of the unequal-thickness blank forged by the overall loading of the titanium alloy rib plate member with the "Z" interface, but it does not take into account the local loading characteristics of the mold partition, and the experimental method is long and expensive, especially for large-scale Integral members like stiffeners limit the application of this method.

张大伟等在Journal Materials Processing Technology第210卷，2期，258-266页上发表的Analysis of local loading forming for titanium-alloy T-shaped components usingslab method论文中建立模具分区导致的局部加载状态下的材料分流层处到筋型腔中心的距离计算公式，具体地如下：Zhang Dawei et al. published Analysis of local loading forming for titanium-alloy T-shaped components using slab method paper on Journal Materials Processing Technology Volume 210, Issue 2, Page 258-266 to establish material shunting under local loading state caused by mold partitioning The formula for calculating the distance from the layer to the center of the rib cavity is as follows:

模具分区导致的局部加载状态下的下的材料分流层处到筋型腔中心的距离x_k采用公式(1)计算：The distance x _k from the lower material distribution layer to the center of the rib cavity under the local loading state caused by mold partitioning is calculated by formula (1):

$\{\begin{matrix} {x x}_{k k} = = \frac{b b}{22} & {σ σ}_{x x} {| |}_{x x = = b b / / 22} \leq \leq q q \\ {x x}_{k k} = = \frac{11}{44} ((l l + + b b - - \frac{{H h}^{22}}{mb mb})) & {σ σ}_{x x} {| |}_{x x = = b b / / 22} > > q q \end{matrix} --- --- ((11))$

其中：in:

${σ σ}_{x x} {| |}_{x x = = b b / / 22} = = 22 K K + + \frac{mK mK}{H h} ((l l - - b b))$

$q q = = 22 K K ((11 + + \frac{H h}{22 b b}))$

式中：K为材料剪切屈服强度；b为筋宽；l为局部加载宽度；H为加载区坯料厚度；m为常剪切摩擦因子；σ_x为材料未流向筋型腔的腹板区内坯料X轴方向的应力，所述的腹板区内坯料同加载上模和下模同时接触；q为坯料内筋和腹板相交界面上的X轴方向的平均单位压力，所述的筋和腹板相交界面同筋型腔侧壁重合。In the formula: K is the material shear yield strength; b is the rib width; l is the local loading width; H is the blank thickness in the loading area; m is the constant shear friction factor; σ _x is the web area where the material does not flow to the rib cavity The stress in the X-axis direction of the inner blank, the blank in the web area is in contact with the loaded upper mold and the lower mold at the same time; q is the average unit pressure in the X-axis direction on the intersection interface between the inner rib and the web of the blank, and the rib The intersecting interface with the web coincides with the side wall of the rib cavity.

为改善型腔充填，采用不等厚坯料。所述不等厚坯料的表面为阶梯状，该阶梯的厚度差为ΔH。但是公式(1)不适用于由该厚度差导致的局部加载状态下材料分流层处的计算。In order to improve cavity filling, blanks of unequal thickness are used. The surface of the unequal-thickness blank is stepped, and the thickness difference of the step is ΔH. But the formula (1) is not applicable to the calculation at the material separation layer under the local loading state caused by the thickness difference.

对于类似于图4所示的隔框构件，张大伟等人(张大伟，杨合，孙志超，樊晓光.大型复杂筋板类构件局部加载等温成形宏微观模型[C].第三届全国精密锻造学术研讨会论文集，2008年12月3-5日，江苏盐城：104-111)指出根据构件的结构特征该类整体构件可看作为由框形构件6和筋板形构件7整体组合而成。For bulkhead members similar to those shown in Figure 4, Zhang Dawei et al. (Zhang Dawei, Yang He, Sun Zhichao, Fan Xiaoguang. Macro-micro model of isothermal forming of large complex ribbed members with local loading [C]. The Third National Academic Seminar on Precision Forging Conference Proceedings, December 3-5, 2008, Yancheng, Jiangsu: 104-111) pointed out that according to the structural characteristics of the components, such integral components can be regarded as an integral combination of frame-shaped components 6 and rib-shaped components 7.

所述的框形构件6的横截面为“工”字形；两侧侧壁为弧形或直线或弧形和直线的组合；两侧侧壁之间分布有筋条；两侧之间的距离远远小于侧壁的长度，根据“形状分类法”(T.阿尔坦等著，陆索译.现代锻造——设备、材料和工艺[M].北京：国防工业出版社，1982)该构件可归为“长形锻件”，所述“长形锻件”的一个主尺寸显著地大于其余二个尺寸；高宽比(h/b＞1)显著的筋条分布密集，区域内的筋条交错分布。The cross-section of the frame member 6 is "I" shape; the side walls on both sides are arc-shaped or straight line or a combination of arc-shape and straight line; ribs are distributed between the side walls on both sides; the distance between the two sides Far less than the length of the side wall, according to the "shape classification method" (T. Altan et al., translated by Lu Suo. Modern forging - equipment, materials and processes [M]. Beijing: National Defense Industry Press, 1982) the component It can be classified as "long forging", one of the main dimensions of the "long forging" is significantly larger than the other two dimensions; the distribution of ribs with significant aspect ratio (h/b>1) is dense, and the ribs in the area Staggered distribution.

所述的筋板形构件近似矩形；根据“形状分类法”(T.阿尔坦等著，陆索译.现代锻造——设备、材料和工艺[M].北京：国防工业出版社，1982)该构件可归为“盘形锻件”，所述“盘形锻件”的三个尺寸中有二个尺寸大致相等，并且大于锻件的另一尺寸；高宽比(h/b＞1)显著的筋条的分布较框形构件稀松，大部分区域的筋条沿一个方向分布。The rib-shaped member is approximately rectangular; according to the "shape classification method" (T. Altan et al., translated by Lu Suo. Modern Forging - Equipment, Materials and Technology [M]. Beijing: National Defense Industry Press, 1982) The member may be classified as a "disc forging" in which two of the three dimensions are approximately equal and greater than the other dimension of the forging; the aspect ratio (h/b > 1) is significant The distribution of ribs is looser than that of frame members, and the ribs in most areas are distributed in one direction.

杨合等人(孙念光，杨合，孙志超.大型钛合金隔框等温闭式模锻成形工艺优化[J].稀有金属与工程，2009，38(7)：1296-1300；Z.C.Sun，H.Yang.Forming quality of titaniumalloy large-scale integral components isothermal local loading[J].The Arabian Journal forScience and Engineering，2009，34(1C)：35-45)根据充填效果将构件分为难成形区和易成形区，也分别对应于上述的框形构件6和筋板形构件7。Yang He et al. (Sun Nianguang, Yang He, Sun Zhichao. Optimization of isothermal closed die forging process for large titanium alloy frame[J]. Rare Metals and Engineering, 2009, 38(7): 1296-1300; Z.C.Sun, H. Yang. Forming quality of titanium alloy large-scale integral components isothermal local loading[J]. The Arabian Journal for Science and Engineering, 2009, 34(1C): 35-45) according to the filling effect, the components are divided into difficult-to-form areas and easy-to-form areas. They also correspond to the above-mentioned frame-shaped member 6 and rib-shaped member 7 respectively.

发明内容 Contents of the invention

为克服现有技术中存在的或者部分区域不能充满，或者没有考虑到模具分区的局部加载特征，或者成本高的不足，本发明提出了一种确定三维框形构件局部加载成形用不等厚坯料的方法。In order to overcome the disadvantages existing in the prior art that some areas cannot be filled, or the local loading characteristics of the mold partitions are not considered, or the high cost is high, the present invention proposes a blank with different thicknesses for determining the local loading of three-dimensional frame members. Methods.

本发明包括以下步骤：The present invention comprises the following steps:

步骤1，确定构件的界面；界面由弧形界面和同X方向垂直的直线界面两部分组成并贯穿两个加载区；所述的界面平行于构件宽度的中心线Step 1, determine the interface of the component; the interface is composed of two parts: an arc interface and a straight line interface perpendicular to the X direction and runs through two loading areas; the interface is parallel to the centerline of the component width

步骤2，简化确定的界面；所确定的界面上表面和下表面均对称地分布有多个筋条；以构件厚度方向的对称中心线一侧为简化界面，并将该简化界面内的各筋条分别记为第i筋，i＝1～n；成形简化界面的筋条采用局部加载成形，加载中模具分区位置为分区筋的中心处；确定第2筋～第n-1筋中的一个筋条为分区筋；Step 2, simplify the determined interface; the upper surface and the lower surface of the determined interface are symmetrically distributed with multiple ribs; the side of the symmetrical center line in the thickness direction of the member is used as the simplified interface, and the ribs in the simplified interface are Each bar is recorded as the i-th rib, i=1~n; the ribs in the forming simplified interface are formed by local loading, and the partition position of the mold during loading is the center of the partitioned ribs; determine one of the 2nd ribs to the n-1th ribs Ribs are partitioned ribs;

步骤3，确定简化界面处所需不等厚坯料形状；通过对简化界面进行快速分析实现确定简化界面处所需不等厚坯料形状；在对简化界面做快速分析时，取一块不等厚坯料作为初始坯料，并根据初始坯料确定简化界面的坯料形状；对简化界面做快速分析中，有三种局部加载状态和一种整体加载状态；所述三种局部加载状态分别是，由于模具部分加载形成的第一种局部加载状态、由不同腹板区模具的不同深度形成的第二种局部加载状态，以及由不等厚坯料的阶梯状表面存在的阶梯厚度差ΔH导致的第三种局部加载状态；在对各简化界面进行快速分析，以整体下模的各筋型腔处建立局部直角坐标系；所述局部直角坐标系的Y坐标位于所处筋型腔宽度的对称中心，并且各局部直角坐标系的坐标原点位于该Y坐标与X坐标的交点处；Step 3, determine the shape of the blank with different thickness required at the simplified interface; through a quick analysis of the simplified interface, determine the shape of the blank with different thickness required at the simplified interface; when doing a quick analysis of the simplified interface, take a piece of blank with different thickness As the initial blank, the blank shape of the simplified interface is determined according to the initial blank; in the quick analysis of the simplified interface, there are three local loading states and one overall loading state; the three local loading states are respectively formed due to partial loading of the mold The first local loading state of , the second local loading state formed by the different depths of the mold in different web regions, and the third local loading state caused by the step thickness difference ΔH existing on the stepped surface of the unequal-thickness blank ; Carry out rapid analysis to each simplified interface, and establish a local rectangular coordinate system at each rib cavity of the overall lower die; the Y coordinate of the local rectangular coordinate system is located at the symmetry center of the rib cavity width, and each local rectangular coordinate system The coordinate origin of the coordinate system is located at the intersection of the Y coordinate and the X coordinate;

对简化界面进行快速分析，确定简化界面的坯料形状；具体过程：Quickly analyze the simplified interface and determine the blank shape of the simplified interface; the specific process:

a.根据简化界面局部加载成形中的加载状态确定分流层位置及筋型腔充填材料体积计算公式；a. According to the loading state in the simplified interface local loading forming, determine the position of the separation layer and the calculation formula of the filling material volume of the rib cavity;

根据简化界面处所需不等厚坯、模具的几何结构特征，局部加载成形过程中会出现三种局部加载状态和一种整体加载状态；According to the geometric structure characteristics of unequal thickness blanks and molds required at the simplified interface, there will be three local loading states and one overall loading state during the local loading forming process;

第一种局部加载状态；坯料下表面与下模具配合；下模具表面有筋条的成形型腔；所述的第一种局部加载状态位于加载区内靠近分模位置的第一个完整筋型腔到分模位置之间；当这一区域内的坯料同加载上模和下模完全接触，此时该区域的加载状态为第一种局部加载状态；The first partial loading state; the lower surface of the blank is matched with the lower mold; the forming cavity with ribs on the surface of the lower mold; the first partial loading state is located in the first complete rib near the parting position in the loading area Between the cavity and the parting position; when the blank in this area is in full contact with the loaded upper and lower dies, the loading state of this area is the first partial loading state;

第一种局部加载状态下，局部加载宽度即为出现第一种局部加载状态区域内靠近分模位置的第一个完整筋型腔中心到分区筋型腔侧壁之间距离的二倍，所述分区筋型腔侧壁是该筋型腔出现第一种局部加载状态一侧的侧壁；局部加载宽度l在局部加载阶段中不变化，出现第一种局部加载状态区域内的坯料厚度H同上模行程之间是线性关系；采用计算公式(1)计算第一种局部加载状态下的材料分流层处到筋型腔中心的距离x_k：In the first partial loading state, the local loading width is twice the distance from the center of the first complete rib cavity close to the parting position in the area where the first partial loading state occurs to the side wall of the partitioned rib cavity, so The side wall of the rib cavity in the above partition is the side wall on the side where the first local loading state occurs in the rib cavity; the local loading width l does not change in the partial loading stage, and the blank thickness H in the area where the first partial loading state occurs There is a linear relationship between the travel of the upper die; use formula (1) to calculate the distance x _k from the material distribution layer to the center of the rib cavity under the first local loading state:

其中：in:

$q q = = 22 K K ((11 + + \frac{H h}{22 b b}))$

式中：K为材料剪切屈服强度；b为筋宽；l为局部加载宽度；H为出现第一种局部加载状态区域坯料厚度；m为常剪切摩擦因子；σ_x为材料未流向筋型腔的腹板区内坯料X轴方向的应力，所述的腹板区内坯料同加载上模和下模同时接触；q为坯料内筋和腹板相交界面上的X轴方向的平均单位压力，所述的筋和腹板相交界面同筋型腔侧壁重合；式(1)中所采用的局部坐标系为简化界面中坯料所流入筋型腔的局部坐标系；In the formula: K is the shear yield strength of the material; b is the rib width; l is the local loading width; H is the blank thickness in the area where the first local loading state occurs; _m is the constant shear friction factor; Stress in the X-axis direction of the billet in the web area of the cavity, where the billet in the web area is in contact with the loaded upper die and lower die at the same time; q is the average unit of the X-axis direction on the interface between the inner rib of the billet and the web pressure, the intersecting interface between the rib and the web coincides with the side wall of the rib cavity; the local coordinate system adopted in the formula (1) is the local coordinate system of the blank flowing into the rib cavity in the simplified interface;

成形过程中出现第一种局部加载状态区域坯料厚度H同加载上模行程s的关系由式(2)确定：In the forming process, the relationship between the thickness H of the blank in the area of the first local loading state and the stroke s of the loaded upper die is determined by formula (2):

H＝H₀-s (2)H＝H ₀ -s (2)

式中：H₀为出现第一种局部加载状态区域初始坯料厚度；s为加载上模行程；In the formula: H ₀ is the initial blank thickness in the area where the first local loading state occurs; s is the stroke of the loaded upper die;

流入筋型腔的材料体积V_in由式(3)确定：The material volume V _in flowing into the rib cavity is determined by formula (3):

${V V}_{in in} = = {&Integral; &Integral;}_{{s the s}_{11}}^{{s the s}_{22}} {x x}_{k k} ((s the s)) ds ds - - - - - - ((33))$

流入分区筋型腔的材料体积V_out由式(4)确定：The material volume V _out flowing into the partition rib cavity is determined by formula (4):

${V V}_{out out} = = {&Integral; &Integral;}_{{s the s}_{11}}^{{s the s}_{22}} [[\frac{l l}{22} - - {x x}_{k k} ((s the s))]] ds ds - - - - - - ((44))$

第二种局部加载状态；坯料下表面与下模具配合；下模具表面有筋条的成形型腔；筋的两侧腹板厚度变化，在加载成形中，当该筋型腔与一侧相邻筋型腔之间的坯料同加载上模和下模完全接触，而所述该筋型腔与另一侧相邻筋型腔之间的坯料没有同加载上模和下模完全接触，此时所述该筋型腔与所述一侧相邻筋型腔之间的加载状态为第二种局部加载状态；The second partial loading state: the lower surface of the billet is matched with the lower mold; there is a forming cavity with ribs on the surface of the lower mold; the thickness of the web on both sides of the rib changes. In the loading forming, when the rib cavity is adjacent to one side The blank between the rib cavities is in full contact with the loaded upper die and lower die, while the blank between the rib cavity and the adjacent rib cavity on the other side is not in full contact with the loaded upper die and lower die. The loading state between the rib cavity and the adjacent rib cavity on one side is the second partial loading state;

第二种局部加载状态下，局部加载宽度即为所述该筋型腔侧壁到该侧相邻筋型腔中心之间距离的二倍，局部加载宽度l在局部加载阶段中不变化，出现第二种局部加载状态区域内的坯料厚度H同上模行程之间是线性关系；所述筋型腔侧壁是该筋型腔出现第二种局部加载状态一侧的侧壁；采用公式(1)计算第二种局部加载状态下的材料分流层处到筋型腔中心的距离x_k；公式(1)中的H为出现第二种局部加载状态区域坯料厚度；In the second partial loading state, the local loading width is twice the distance between the side wall of the rib cavity and the center of the adjacent rib cavity on this side, and the local loading width l does not change during the partial loading stage, and appears There is a linear relationship between the blank thickness H in the second local loading state area and the stroke of the upper die; the rib cavity side wall is the side wall on the side of the rib cavity where the second local loading state occurs; formula (1 ) Calculate the distance x _k from the material distribution layer to the center of the rib cavity under the second local loading state; H in the formula (1) is the thickness of the blank in the second local loading state area;

成形过程中出现第二种局部加载状态区域坯料厚度H同加载上模行程s的关系由式(2)确定：公式(2)中的H₀为出现第二种局部加载状态区域初始坯料厚度；The relationship between the thickness H of the blank in the region where the second partial loading state occurs during the forming process and the stroke s of the loaded upper die is determined by the formula (2): _H0 in the formula (2) is the initial thickness of the blank in the region where the second partial loading state occurs;

流入筋型腔的材料体积V_in由式(3)确定；The material volume V _in flowing into the rib cavity is determined by formula (3);

第三种局部加载状态；坯料下表面与下模具配合；下模具表面有筋条的成形型腔；所述不等厚坯料的表面为阶梯状，该阶梯的厚度差为ΔH；所述的第三种局部加载状态位于下模具的各筋条成形型腔之间，或者位于构件一端临近端头处的筋条成形型腔到所述下模该端的端面内侧壁之间，或者位于下模具的各筋条成形型腔之间和构件一端临近端头处的筋条成形型腔到所述下模该端的端面内侧壁之间；并且该区域坯料同下模完全接触，此时该区域的加载状态为第三种局部加载状态；The third partial loading state: the lower surface of the blank is matched with the lower mold; the forming cavity with ribs on the surface of the lower mold; the surface of the blank with different thickness is stepped, and the thickness difference of the step is ΔH; the first The three local loading states are located between the rib forming cavities of the lower mold, or between the rib forming cavity at one end of the component near the end and the inner side wall of the end face of the lower mold, or between the rib forming cavity at the end of the lower mold. Between the rib forming cavities and between the rib forming cavity near the end of one end of the component and the inner side wall of the end face of the lower die; and the blank in this area is in full contact with the lower die, and the loading in this area The state is the third partial loading state;

第三种局部加载状态下，局部加载宽度即为出现第三种局部加载状态区域内坯料同上模和下模都同时接触部分的宽度的二倍，该局部加载宽度l在局部加载阶段中随加载过程是动态变化的，出现第三种局部加载状态区域内的H和ΔH同上模行程之间是非线性相关的；第三种局部加载状态下的材料分流层处到筋型腔中心的距离x_k由式(5)确定：In the third partial loading state, the local loading width is twice the width of the part where the billet is in contact with the upper die and the lower die at the same time in the area where the third partial loading state occurs. The process is dynamic, and there is a nonlinear relationship between H and ΔH in the region of the third local loading state and the stroke of the upper die; the distance x _k from the material distribution layer to the center of the rib cavity in the third local loading state Determined by formula (5):

$\{\begin{matrix} {x x}_{k k} = = \frac{b b}{22} & {σ σ}_{x x} {| |}_{x x = = b b / / 22} \leq \leq q q \\ {x x}_{k k} = = \frac{11}{44} ((l l + + b b)) - - \frac{ΔH ΔH}{22 m m} ((11 + + \frac{H h + + ΔH ΔH}{22 b b})) & {σ σ}_{x x} {| |}_{x x = = b b / / 22} > > q q \end{matrix} --- --- ((55))$

其中：in:

${σ σ}_{x x} {| |}_{x x = = b b / / 22} = = \frac{mK mK}{ΔH ΔH} ((l l - - b b))$

$q q = = 22 K K ((11 + + \frac{H h + + ΔH ΔH}{22 b b}))$

式中：K为材料剪切屈服强度；b为筋宽；l为局部加载宽度；ΔH为变厚度区的厚度差；H为变厚度区内未同加载上模接触的坯料厚度；m为常剪切摩擦因子；σ_x为材料未流向筋型腔腹板区内坯料X轴方向的应力，所述的腹板区内坯料同加载上模和下模同时接触；q为坯料内筋和腹板相交界面上的X轴方向的平均单位压力，所述的筋和腹板相交界面同筋型腔侧壁重合；式(5)中所采用的局部坐标系为简化界面中坯料所流入筋型腔的局部坐标系；In the formula: K is the shear yield strength of the material; b is the rib width; l is the local loading width; ΔH is the thickness difference in the variable thickness area; Shear friction factor; _σx is the stress in the X-axis direction of the blank in the web area of the rib cavity where the material does not flow to the web area, and the blank in the web area is in contact with the loaded upper die and lower die at the same time; q is the inner rib and web of the billet The average unit pressure in the X-axis direction on the plate intersection interface, the intersection interface of the rib and the web coincides with the side wall of the rib cavity; the local coordinate system used in the formula (5) is the simplified The local coordinate system of the cavity;

成形过程中，局部加载宽度l的动态变化由式(6)确定：During the forming process, the dynamic change of the local loading width l is determined by formula (6):

l＝l₀+b₁s+b₂s²(6)l＝l ₀ +b ₁ s+b ₂ s ² (6)

式中l₀为初始局部加载宽度；s为加载上模行程；b₁为一次项系数；b₂为二次项系数；b₁和b₂分别由式(7)和式(8)确定：In the formula, l ₀ is the initial local loading width; s is the stroke of the loading upper die; b ₁ is the first-order coefficient; b ₂ is the quadratic coefficient; b ₁ and b ₂ are determined by formula (7) and formula (8) respectively:

ln(b₁)＝1.16941+0.03880A-0.13668B-0.33010C-0.47077D-0.04376R+0.17274lnA+0.73480lnB-0.39029lnC+0.64892lnR (7)ln(b ₁ )＝1.16941+0.03880A-0.13668B-0.33010C-0.47077D-0.04376R+0.17274lnA+0.73480lnB-0.39029lnC+0.64892lnR (7)

ln(b₂)＝-1.01970-0.03751A+0.74384B-0.04876C-0.22359D+1.19454R+0.94165lnA-3.74272lnB-0.45123lnC-1.50094lnR (8)ln(b ₂ )＝-1.01970-0.03751A+0.74384B-0.04876C-0.22359D+1.19454R+0.94165lnA-3.74272lnB-0.45123lnC-1.50094lnR (8)

式中A为l₀/b的比值，B为L/l₀的比值，C为H₀/b的比值，D为ΔH₀/H₀的比值；L为筋型腔中心到厚度H坯料区域的约束端之间距离的二倍；R为变厚度区的过渡条件，定义为宽度增量Δl和厚度差ΔH的比，即为Δl/ΔH；In the formula, A is the ratio of l ₀ /b, B is the ratio of L/l ₀ , C is the ratio of H ₀ /b, D is the ratio of ΔH ₀ /H ₀ ; L is the area from the center of rib cavity to thickness H blank Twice the distance between the constrained ends; R is the transition condition of the variable thickness zone, defined as the ratio of the width increment Δl to the thickness difference ΔH, which is Δl/ΔH;

成形过程中变厚度区的厚度差ΔH由式(9)确定：The thickness difference ΔH in the variable thickness zone during the forming process is determined by formula (9):

ΔH＝C₁-s-H (9)ΔH＝C ₁ -sH (9)

式中：C1为ΔH₀加H₀之和；ΔH₀为初始厚度差；H₀为变厚度区内未同加载上模接触的初始坯料厚度；In the formula: C1 is the sum of ΔH ₀ plus H ₀ ; ΔH ₀ is the initial thickness difference; H ₀ is the initial blank thickness that is not in contact with the loaded upper die in the variable thickness area;

令make

K₁＝L-l₀，K ₁ =Ll ₀ ,

K₂＝-b₁C₁-b+l₀，K ₂ =-b ₁ C ₁ -b+l ₀ ,

K₃＝-2(b₂C₁-b₁)，K ₃ =-2(b ₂ C ₁ -b ₁ ),

${K K}_{44} = = {b b}_{11} - - \frac{11}{m m} - - \frac{{C C}_{11}}{22 mb mb},,$

${K K}_{55} = = {22 b b}_{22} + + \frac{11}{22 mb mb},,$

${K K}_{66} = = - - {C C}_{11} {K K}_{44} + + \frac{11}{22} (({l l}_{00} - - b b)),,$

${K K}_{77} = = \frac{{b b}_{11}}{22} + + {K K}_{44} - - {C C}_{11} {K K}_{55},,$

${K K}_{88} = = {K K}_{55} + + \frac{{b b}_{22}}{22},,$

所述K₁～K₈均为(10)和式(11)中的简化项；The K ₁ to K ₈ are simplified terms in (10) and formula (11);

流入筋型腔的材料体积V_in由式(10)或式(11)微分方程组确定：The material volume V _in flowing into the rib cavity is determined by the differential equations of formula (10) or formula (11):

当σ_x|_x＝b/2≤q时有： $\{\begin{matrix} (K_{1} - b_{1} s - b_{2} s^{2}) \frac{dH}{ds} - (b_{1} + {2 b}_{2} s) H = K_{2} + K_{3} s + {3 b}_{2} s^{2} \\ \frac{{dV}_{in}}{ds} = \frac{b}{2} \end{matrix} - - - (10)$ When σ _x | _{x = b/2} ≤ q: $\{\begin{matrix} (K_{1} - b_{1} the s - b_{2} {the s}^{2}) \frac{dH}{ds} - (b_{1} + {2 b}_{2} the s) h = K_{2} + K_{3} the s + {3 b}_{2} {thes}^{2} \\ \frac{{dV}_{in}}{ds} = \frac{b}{2} \end{matrix} - - - (10)$

当σ_x|_x＝b/2＞q时有： $\{\begin{matrix} (K_{1} - b_{1} s - b_{2} s^{2}) \frac{dH}{ds} - (K_{4} + K_{5} s) H = K_{6} + K_{7} s + K_{8} s^{2} \\ \frac{{dV}_{in}}{ds} = \frac{1}{4} (l_{0} + b + b_{1} s + b_{2} s^{2}) - \frac{C_{1} - s - H}{2 m} (1 + \frac{C_{1} - s}{2 b}) \end{matrix} - - - (11)$ When σ _x | _{x = b/2} > q: $\{\begin{matrix} (K_{1} - b_{1} the s - b_{2} {the s}^{2}) \frac{dH}{ds} - (K_{4} + K_{5} the s) h = K_{6} + K_{7} the s + K_{8} {thes}^{2} \\ \frac{{dV}_{in}}{ds} = \frac{1}{4} (l_{0} + b + b_{1} the s + b_{2} {the s}^{2}) - \frac{C_{1} - the s - h}{2 m} (1 + \frac{C_{1} - the s}{2 b}) \end{matrix} - - - (11)$

根据初值条件可用数值方法求解式(10)、式(11)；According to the initial value condition, formula (10) and formula (11) can be solved numerically;

整体加载状态；坯料下表面与下模具配合；下模具表面有筋条的成形型腔；所述的整体加载状态位于下模具的各筋条成形型腔之间，或者位于构件一端临近端头处的筋条成形型腔到所述下模该端的端面内侧壁之间，或者位于下模具的各筋条成形型腔之间和构件一端临近端头处的筋条成形型腔到所述下模该端的端面内侧壁之间；并且该区域坯料同加载上模和下模完全接触，此时该区域的加载状态为整体加载状态；The overall loading state; the lower surface of the blank is matched with the lower mold; the forming cavity with ribs on the surface of the lower mold; the overall loading state is located between the rib forming cavities of the lower mold, or at one end of the component near the end between the rib forming cavities of the lower mold and the inner side wall of the end face of the lower mold, or between the rib forming cavities of the lower mold and the rib forming cavity near the end of one end of the component to the lower mold Between the inner wall of the end face of this end; and the blank in this area is in full contact with the loaded upper die and lower die, and the loading state of this area is the overall loading state at this time;

当构件一端临近端头处的筋条成形型腔到所述下模该端的端面内侧壁之间为整体加载状态，则材料分流层处到该筋条成形型腔中心的距离x_k为所述下模该端的端面内侧壁到该筋条成形型腔中心的距离；When one end of the member is near the end of the rib forming cavity to the inner wall of the end face of the lower die, it is in an integral loading state, then the distance x _k from the material distribution layer to the center of the rib forming cavity is the The distance from the inner side wall of the end face of the lower die to the center of the rib forming cavity;

当第i个筋型腔和第i+1个筋型腔之间为整体加载状态时，则材料分流层处到第i个筋型腔中心的距离x_k由式(12)确定：When the overall loading state is between the i-th rib cavity and the i+1-th rib cavity, the distance x _k from the material separation layer to the center of the i-th rib cavity is determined by formula (12):

${x x}_{k k} = = \frac{{a a}_{i i,, i i + + 11}}{22} + + \frac{{b b}_{i i} - - {b b}_{i i + + 11}}{44} + + \frac{{H h}^{22}}{44 m m} ((\frac{11}{{b b}_{i i + + 11}} - - \frac{11}{{b b}_{i i}})) - - - - - - ((1212))$

式中：a_i，i+1为第i个筋型腔中心和第i+1个筋型腔中心之间的距离；b_i为第i个筋的筋宽；b_i+1为第i+1个筋的筋宽；H为出现整体加载状态区域坯料厚度；m为常剪切摩擦因子；In the formula: a _{i, i+1} is the distance between the center of the i-th rib cavity and the center of the i+1-th rib cavity; b _i is the width of the i-th rib; b _i+1 is the i-th rib +1 rib width; H is the thickness of the blank in the area where the overall loading state occurs; m is the constant shear friction factor;

成形过程中出现整体加载状态区域坯料厚度H同加载上模行程s的关系由式(13)确定：The relationship between the thickness H of the blank in the area of the overall loading state in the forming process and the stroke s of the loaded upper die is determined by formula (13):

H＝H₀-s (13)H＝H ₀ -s (13)

式中：H₀为出现整体加载状态区域初始坯料厚度；s为加载上模行程；In the formula: H ₀ is the initial blank thickness in the area where the overall loading state occurs; s is the stroke of the upper die for loading;

流入筋型腔的材料体积V_in由式(14)确定：The material volume V _in flowing into the rib cavity is determined by formula (14):

${V V}_{in in} = = {&Integral; &Integral;}_{{s the s}_{11}}^{{s the s}_{22}} {x x}_{k k} ((s the s)) ds ds - - - - - - ((1414))$

b.简化界面局部加载成形过程成形筋高的解析计算；b. Simplify the analytical calculation of the forming rib height during the local loading forming process at the interface;

第一加载步中流入简化界面各筋型腔的材料体积计算：Calculation of the volume of material flowing into each rib cavity of the simplified interface in the first loading step:

确定第一加载上模的最大行程，取计算步长Δs，所述Δs的取值范围为0.01～0.1；Determine the maximum stroke of the first loaded upper die, and take the calculation step size Δs, and the value range of the Δs is 0.01 to 0.1;

在步长Δs内，根据步骤a，确定简化界面第i个筋型腔两侧的加载状态，i＝1～n；根据加载状态、筋型腔和坯料的几何参数、摩擦条件分别计算流入简化界面的第i个筋型腔的材料体积；第i个筋型腔两侧坯料未同上模具和下模具接触，流入筋型腔材料体积为零；至此完成一个步长Δs的计算；记录得到的每个筋型腔的材料体积，更新坯料几何参数和接触情况；Within the step length Δs, according to step a, determine the loading state on both sides of the i-th rib cavity on the simplified interface, i=1~n; calculate the inflow simplification according to the loading state, geometric parameters of the rib cavity and blank, and friction The material volume of the i-th rib cavity on the interface; the blanks on both sides of the i-th rib cavity are not in contact with the upper mold and the lower mold, and the volume of the material flowing into the rib cavity is zero; so far, the calculation of a step length Δs is completed; record the obtained The material volume of each rib cavity, update the blank geometric parameters and contact conditions;

根据步骤a，重复上述过程，继续确定各筋型腔两侧的加载状态并计算流入各筋型腔的材料体积；所述继续确定各筋型腔两侧的加载状态并计算流入各筋型腔的材料体积过程中，累加计算步长Δs，直至完成第一加载上模的最大行程，得到流入各筋型腔的材料体积；According to step a, repeat the above process, continue to determine the loading state on both sides of each rib cavity and calculate the volume of material flowing into each rib cavity; In the process of material volume, the cumulative calculation step length Δs, until the maximum stroke of the first loaded upper die is completed, and the material volume flowing into each rib cavity is obtained;

完成第一加载步的计算后，在部分区域成形筋条的坯料形状基础上，进行第二加载步中流入简化界面各筋型腔的材料体积计算：After the calculation of the first loading step is completed, on the basis of the blank shape of the formed rib in some areas, the material volume flowing into each rib cavity of the simplified interface in the second loading step is calculated:

确定第二加载上模的最大行程，取计算步长Δs，所述Δs的取值范围为0.01～0.1；Determine the maximum stroke of the second loaded upper die, take the calculation step size Δs, and the value range of the Δs is 0.01 to 0.1;

根据步骤a，重复上述过程，继续确定各筋型腔两侧的加载状态并计算流入各筋型腔的材料体积；继续确定各筋型腔两侧的加载状态并计算流入各筋型腔的材料体积过程中，累加计算步长Δs，直至完成第二加载上模的最大行程，得到流入各筋型腔的材料体积；According to step a, repeat the above process, continue to determine the loading state on both sides of each rib cavity and calculate the volume of material flowing into each rib cavity; continue to determine the loading state on both sides of each rib cavity and calculate the material flowing into each rib cavity In the process of volume, accumulatively calculate the step length Δs until the maximum stroke of the second loaded upper die is completed, and the volume of material flowing into each rib cavity is obtained;

完成两个加载步的计算，简化界面中各筋的成形筋高h分别由式(15)确定：Completing the calculation of the two loading steps, the formed rib height h of each rib in the simplified interface is determined by formula (15):

$h h = = \frac{{V V}_{in in}^{tot tot}}{b b} - - - - - - ((1515))$

式中

整个成形过程中流入筋型腔的材料体积；In the formula

The volume of material flowing into the rib cavity throughout the forming process;

c.基于解析结果修改不等厚坯料，简化界面局部加载成形过程成形筋高的解析计算；根据解析结果修改不等厚坯料，并执行简化界面局部加载成形过程成形筋高的解析计算，当计算的成形筋高同设计要求筋高之间的高度差e_h的最大值max(e_h)小于10-15％时，停止修改坯料；获得简化界面所需的不等厚坯料形状；c. Modify unequal-thickness blanks based on the analytical results, simplify the analytical calculation of the forming rib height in the process of local loading on the interface; modify the unequal-thickness blanks based on the analytical results, and perform the analytical calculation of the forming rib height in the simplified interface local loading forming process. When the maximum value max(e _h ) of the height difference e _h between the formed rib height and the designed rib height is less than 10-15%, stop modifying the blank; obtain the unequal thickness blank shape required by the simplified interface;

步骤4，确定基本不等厚坯料形状；Step 4, determining the shape of the basic unequal-thickness blank;

a.根据步骤3获得的简化界面上的不等厚坯料形状，确定三维不等厚坯料，同时根据如下变厚度区设置原则：a. According to the shape of the unequal-thickness blank on the simplified interface obtained in step 3, determine the three-dimensional unequal-thickness blank, and at the same time according to the following principles for setting the variable thickness area:

变厚度区过渡条件R＞1；The transition condition of variable thickness zone R>1;

坯料变厚度区应当避免设置在分模位置附近和筋型腔附近；The variable thickness area of the billet should avoid being set near the parting position and the rib cavity;

若在筋型腔或模具分区附近设置变厚度区，需采用较大的过渡条件，即R＞2；If a variable thickness zone is set near the rib cavity or the mold partition, a larger transition condition must be adopted, that is, R>2;

得到构件厚度方向中心线一侧的不等厚坯料；Obtain blanks of unequal thickness on one side of the center line in the thickness direction of the component;

b.构件上表面和下表面对称地分布有筋条，将a得到的不等厚坯料镜像，使坯料上表面和下表面对称地分布变厚度区，获得整体构件局部加载成形用三维基本不等厚坯料；b. Ribs are symmetrically distributed on the upper surface and lower surface of the member, and the unequal-thickness blank obtained in a is mirrored, so that the upper surface and lower surface of the blank are symmetrically distributed in the variable thickness area, and the three-dimensional basic unequal for the local loading and forming of the overall member is obtained. thick blank;

步骤5，根据构件形状确定最终不等厚坯料；通过计算机数值模拟分析确定不等厚坯料；数值模拟分析步骤4中的基本不等厚坯料的成形过程；第一加载步对第一加载上模加载，第二加载步对第二加载上模加载；两个加载步后若构件形状未满足充填要求，则根据三维数值模拟结果修改坯料形状，直至得到满足充填要求的不等厚坯料。Step 5, determine the final unequal-thickness blank according to the shape of the component; determine the unequal-thickness blank through computer numerical simulation analysis; numerical simulation analysis of the forming process of the basic unequal-thickness blank in step 4; the first loading step on the first loading upper die Loading, the second loading step loads the second loading upper die; after the two loading steps, if the shape of the component does not meet the filling requirements, modify the shape of the blank according to the 3D numerical simulation results until a blank of unequal thickness that meets the filling requirements is obtained.

本发明根据成形过程中的各种加载状态确定了流入筋型腔材料体积的计算公式，实现简化界面的快速分析，缩短了确定坯料形状的时间；根据数值模拟结果修改坯料形状，确定满足充填要求的不等厚坯料，降低了成本；确定的不等厚坯料体积分配合理，消除成形过程中存在的充不满、折叠等缺陷，减少加工余量，降低了成形载荷，并且坯料形状简单易于制坯。According to various loading states in the forming process, the present invention determines the calculation formula for the volume of the material flowing into the rib cavity, realizes the rapid analysis of the simplified interface, and shortens the time for determining the shape of the blank; modifies the shape of the blank according to the numerical simulation results, and determines that the filling requirements are met The unequal-thickness billet reduces the cost; the determined unequal-thickness billet volume distribution is reasonable, eliminating defects such as filling and folding in the forming process, reducing machining allowance, reducing the forming load, and the shape of the billet is simple and easy to make billets .

附图说明 Description of drawings

图1是本发明的流程图。Fig. 1 is a flow chart of the present invention.

图2是不同加载状态示意图，其中，图2a是第一种局部加载状态示意图；图2b是第二种局部加载状态示意图；图2c是第三种局部加载状态示意图；图2d是整体加载状态示意图。Fig. 2 is a schematic diagram of different loading states, wherein Fig. 2a is a schematic diagram of the first partial loading state; Fig. 2b is a schematic diagram of the second partial loading state; Fig. 2c is a schematic diagram of the third partial loading state; Fig. 2d is a schematic diagram of the overall loading state .

图3是定义变厚度区过渡条件示意图。Fig. 3 is a schematic diagram of defining the transition conditions in the variable thickness region.

图4是隔框构件的结构示意图，其中，图4a是隔框构件的结构示意图，图4b是隔框构件的分体示意图。Fig. 4 is a schematic structural view of a frame member, wherein Fig. 4a is a schematic structural view of a frame member, and Fig. 4b is a schematic split view of a frame member.

图5是实施例中模具分区位置及确定界面的位置示意图。Fig. 5 is a schematic diagram of the position of the mold partition and the determination interface in the embodiment.

图6是实施例中的基本不等厚坯料形状。Fig. 6 is the shape of the substantially unequal-thickness blank in the embodiment.

图7是实施例中的数值模拟模型。Fig. 7 is a numerical simulation model in the embodiment.

图8是实施例中的最终不等厚坯料形状。图中，Fig. 8 is the final blank shape of unequal thickness in the embodiment. In the figure,

1.整体下模 2.加载上模 3.未加载上模 4.坯料 5.模具分区位置1. Overall lower mold 2. Loaded upper mold 3. Unloaded upper mold 4. Blank 5. Mold partition position

6.框形构件 7.筋板形构件 8.分区筋 9.界面位置 10.第一加载区6. Frame-shaped member 7. Rib-shaped member 8. Partition rib 9. Interface position 10. First loading area

11.第二加载区 12.整体下模 13.第一加载上模 14.第二加载上模11. The second loading area 12. The overall lower mold 13. The first loading upper mold 14. The second loading upper mold

15.不等厚坯料15. Blanks of different thickness

具体实施方式 Detailed ways

本实施例是一种确定三维框形构件局部加载成形用不等厚坯料的方法，本实施例的构件为框形构件6，如图4b所示，上表面和下表面具有相互对称分布的筋条；上模分为两块，分区筋8中心为模具分区位置；构件的材料为TA15钛合金。本实施例中的成形过程共有两个加载步。This embodiment is a method for determining blanks of unequal thickness for local loading and forming of a three-dimensional frame-shaped member. The member of this embodiment is a frame-shaped member 6, as shown in Figure 4b, the upper surface and the lower surface have mutually symmetrically distributed ribs The upper mold is divided into two pieces, and the center of the partition rib 8 is the mold partition position; the material of the component is TA15 titanium alloy. The forming process in this embodiment has two loading steps.

本实施例中，三维框形构件局部加载成形采用等温成形工艺，成形温度为970℃，上模加载速度为0.2mm/s，取摩擦因子m为0.3。In this embodiment, the isothermal forming process is adopted for the local loading forming of the three-dimensional frame-shaped member, the forming temperature is 970°C, the loading speed of the upper die is 0.2 mm/s, and the friction factor m is taken as 0.3.

本实施例中构件的外形分为两段：一段位于构件的一端，该段的一侧表面为弧形面，另一侧表面为平面，为近似的平面段；该段的构件宽度方向的中心线与平面的侧表面平行；所述的平面侧表面垂直于X方向。另一段为连续的弧形段，并且构件外形的两段之间光滑过渡；该段的中心线位于构件宽度的中心。所述的两段中心线光滑连接。The shape of the component in this embodiment is divided into two sections: one section is located at one end of the component, one side surface of this section is an arc surface, and the other side surface is a plane, which is an approximate plane section; the center of the component width direction of this section is The lines are parallel to the planar side surfaces; said planar side surfaces are perpendicular to the X direction. The other segment is a continuous arcuate segment with a smooth transition between the two segments of the member profile; the centerline of this segment is at the center of the member width. The two sections of centerlines are smoothly connected.

选定弧形段内邻近该弧形段端面的第二个筋条作为分区筋8。分区筋8的中心为模具的分区位置，并由所述模具分区位置形成了第一加载区10和第二加载区11。The second rib adjacent to the end face of the arc segment is selected as the partition rib 8 . The center of the division rib 8 is the division position of the mold, and the first loading area 10 and the second loading area 11 are formed by the division position of the mold.

确定不等厚坯料形状的具体过程包括以下步骤：The specific process of determining the shape of the unequal thickness blank includes the following steps:

步骤1，确定构件的界面。界面9的位置如图5所示。界面9由弧形界面和同X方向垂直的直线界面两部分组成并贯穿两个加载区。所述的界面9平行于构件宽度的中心线。其中，弧形界面位于构件弧形段的横截面上，并靠近弧形构件的内圆表面，位于弧形段横截面的1/3处。Step 1, determine the interface of the component. The position of the interface 9 is shown in FIG. 5 . The interface 9 is composed of an arc interface and a straight line interface perpendicular to the X direction and runs through the two loading areas. Said interface 9 is parallel to the centerline of the component width. Wherein, the arc-shaped interface is located on the cross-section of the arc-shaped segment of the component, and is close to the inner circular surface of the arc-shaped component, and is located at 1/3 of the cross-section of the arc-shaped segment.

步骤2，简化确定的界面；Step 2, simplify the determined interface;

构件的上表面和下表面对称地分布有筋条，步骤1中所确定的界面9上表面和下表面均对称地分布有筋条。简化界面时，以构件厚度方向的对称中心线一侧为简化界面，本实施例中，以构件厚度方向中心线的下表面一侧为简化界面。Ribs are symmetrically distributed on the upper and lower surfaces of the component, and ribs are symmetrically distributed on both the upper and lower surfaces of the interface 9 determined in step 1. When simplifying the interface, the side of the symmetrical centerline in the thickness direction of the component is used as the simplified interface. In this embodiment, the lower surface side of the centerline in the thickness direction of the component is used as the simplified interface.

界面9简化后为简化界面。在简化界面具有5个筋条，从弧形段的一端向该弧形段与平面段衔接一端依次记作简化界面的第1筋条～简化界面的第5筋条。其中，第1筋条为弧形段端头的侧壁，第3筋条为分区筋8；并且所述第1筋条～第4筋条宽度的中心线过所述弧形段的圆心，第5筋条与Y方向垂直。成形简化界面的5个筋条需两个加载步，即局部加载成形，加载中模具分区位置为分区筋8的中心处。The simplified interface 9 is a simplified interface. There are 5 ribs in the simplified interface, which are sequentially recorded as the first rib of the simplified interface to the fifth rib of the simplified interface from one end of the arc segment to the end where the arc segment connects with the plane segment. Wherein, the first rib is the side wall of the end of the arc segment, and the third rib is the partition rib 8; and the center line of the width of the first rib to the fourth rib passes through the center of the arc segment, The fifth rib is perpendicular to the Y direction. Two loading steps are required to form the five ribs in the simplified interface, that is, local loading and forming, and the mold partition position during loading is the center of the partition rib 8.

步骤3，确定简化界面处所需不等厚坯料形状。通过对简化界面进行快速分析实现确定简化界面处所需不等厚坯料形状。在对简化界面做快速分析时，取一块不等厚坯料作为初始坯料，并根据初始坯料确定简化界面的坯料形状。对简化界面做快速分析中，有三种局部加载状态和一种整体加载状态。所述三种局部加载状态分别是，由于模具部分加载形成的第一种局部加载状态、由不同腹板区模具的不同深度形成的第二种局部加载状态，以及由不等厚坯料的阶梯状表面存在的阶梯厚度差ΔH导致的第三种局部加载状态。在对各简化界面进行快速分析，以整体下模1的各筋型腔处建立局部直角坐标系；所述局部直角坐标系的Y坐标位于所处筋型腔宽度的对称中心，并且各局部直角坐标系的坐标原点位于该Y坐标与X坐标的交点处。Step 3, determine the shape of blanks with different thickness required at the simplified interface. Through the quick analysis of the simplified interface, the shape of the billet with different thickness required at the simplified interface can be determined. When doing a quick analysis on the simplified interface, take a blank of unequal thickness as the initial blank, and determine the blank shape of the simplified interface according to the initial blank. In a quick analysis of the simplified interface, there are three partial loading states and one global loading state. The three local loading states are, respectively, the first partial loading state due to partial loading of the mold, the second partial loading state formed by different depths of the mold in different web regions, and the stepped shape of blanks with different thicknesses. The third local loading state caused by the step thickness difference ΔH existing on the surface. After quickly analyzing each simplified interface, a local Cartesian coordinate system is established at each rib cavity of the overall lower die 1; the Y coordinate of the local Cartesian coordinate system is located at the symmetry center of the width of the rib cavity, and each local rectangular coordinate system The coordinate origin of the coordinate system is located at the intersection of the Y coordinate and the X coordinate.

对简化界面进行快速分析，确定简化界面的坯料形状。具体过程：Perform a quick analysis of the simplified interface and determine the blank shape of the simplified interface. Specific process:

a.根据简化界面局部加载成形中的加载状态确定分流层位置及筋型腔充填材料体积计算公式。a. According to the loading state in the simplified interface local loading forming, the position of the distribution layer and the calculation formula of the filling material volume of the rib cavity are determined.

根据简化界面处所需不等厚坯、模具的几何结构特征，局部加载成形过程中会出现三种局部加载状态和一种整体加载状态。According to the unequal thickness billet and the geometrical structure characteristics of the die required at the simplified interface, there will be three local loading states and one overall loading state during the local loading forming process.

第一种局部加载状态，图2a所示；坯料下表面与下模具配合。下模具表面有筋条的成形型腔。所述的第一种局部加载状态位于加载区内靠近分模位置5的第一个完整筋型腔，即第一局部加载步中的第2个筋型腔和第二局部加载步中的第4个筋型腔，到分模位置5之间；当这一区域内的坯料同加载上模和下模完全接触，此时该区域的加载状态为第一种局部加载状态。The first partial loading state is shown in Figure 2a; the lower surface of the billet cooperates with the lower mold. A forming cavity with ribs on the surface of the lower mold. The first partial loading state is located in the first complete rib cavity near the parting position 5 in the loading area, that is, the second rib cavity in the first partial loading step and the first rib cavity in the second partial loading step. Between the 4 rib cavities and the parting position 5; when the blank in this area is in full contact with the loaded upper mold and lower mold, the loading state of this area is the first partial loading state.

第一种局部加载状态下，局部加载宽度即为出现第一种局部加载状态区域内靠近分模位置5的第一个完整筋型腔中心到分区筋型腔侧壁之间距离的二倍，所述分区筋型腔侧壁是该筋型腔出现第一种局部加载状态一侧的侧壁。局部加载宽度l在局部加载阶段中不变化，出现第一种局部加载状态区域内的坯料厚度H同上模行程之间是线性关系。采用计算公式(1)计算第一种局部加载状态下的材料分流层处到筋型腔中心的距离x_k：In the first partial loading state, the local loading width is twice the distance from the center of the first complete rib cavity near the parting position 5 to the side wall of the divided rib cavity in the region where the first partial loading state occurs, The side wall of the partitioned rib cavity is the side wall on the side where the first local loading state occurs in the rib cavity. The local loading width l does not change in the partial loading stage, and the blank thickness H in the region of the first local loading state appears to have a linear relationship with the stroke of the upper die. Calculate the distance x _k from the material distribution layer to the center of the rib cavity under the first local loading state by using the calculation formula (1):

其中：in:

$q q = = 22 K K ((11 + + \frac{H h}{22 b b}))$

式中：K为材料剪切屈服强度；b为筋宽；l为局部加载宽度；H为出现第一种局部加载状态区域坯料厚度；m为常剪切摩擦因子；σ_x为材料未流向筋型腔的腹板区内坯料X轴方向的应力，所述的腹板区内坯料同加载上模和下模同时接触；q为坯料内筋和腹板相交界面上的X轴方向的平均单位压力，所述的筋和腹板相交界面同筋型腔侧壁重合。式(1)中所采用的局部坐标系为简化界面中坯料所流入筋型腔的局部坐标系。In the formula: K is the shear yield strength of the material; b is the rib width; l is the local loading width; H is the blank thickness in the area where the first local loading state occurs; _m is the constant shear friction factor; Stress in the X-axis direction of the billet in the web area of the cavity, where the billet in the web area is in contact with the loaded upper die and lower die at the same time; q is the average unit of the X-axis direction on the interface between the inner rib of the billet and the web pressure, the intersecting interface between the rib and the web coincides with the side wall of the rib cavity. The local coordinate system used in formula (1) is the local coordinate system of the blank flowing into the rib cavity in the simplified interface.

H＝H₀-s (2)H＝H ₀ -s (2)

流入分区筋型腔，即第3个筋型腔，的材料体积V_out由式(4)确定：The material volume V _out flowing into the partitioned rib cavity, that is, the third rib cavity, is determined by formula (4):

第二种局部加载状态，图2b所示；坯料下表面与下模具配合。下模具表面有筋条的成形型腔。第2个筋两侧腹板厚度变化，在第一局部加载步中，当第2个筋型腔和第3个筋型腔之间的坯料同加载上模和下模完全接触，而第2个筋型腔和第1个筋之间的坯料没有同加载上模和下模完全接触，此时第2个筋型腔和第3个筋型腔之间的加载状态为第二种局部加载状态。The second partial loading state is shown in Figure 2b; the lower surface of the billet cooperates with the lower mold. A forming cavity with ribs on the surface of the lower mold. The thickness of the web plate on both sides of the second rib changes. In the first partial loading step, when the blank between the cavity of the second rib and the cavity of the third rib is in full contact with the upper mold and the lower mold for loading, while the second The blank between the first rib cavity and the first rib is not in full contact with the loaded upper mold and lower mold. At this time, the loading state between the second rib cavity and the third rib cavity is the second partial loading. state.

第二种局部加载状态下，局部加载宽度即为第3个筋型腔中心到第2个筋型腔靠近第3个筋型腔的侧壁之间距离的二倍，局部加载宽度l在局部加载阶段中不变化，出现第二种局部加载状态区域内的坯料厚度H同上模行程之间是线性关系。采用计算公式(1)计算第二种局部加载状态下的材料分流层处到筋型腔中心的距离x_k：In the second partial loading state, the local loading width is twice the distance from the center of the third rib cavity to the side wall of the second rib cavity close to the third rib cavity, and the local loading width l is at the local There is no change in the loading stage, and there is a linear relationship between the blank thickness H in the area of the second local loading state and the stroke of the upper die. Use formula (1) to calculate the distance x _k from the material distribution layer to the center of the rib cavity under the second local loading state:

其中：in:

$q q = = 22 K K ((11 + + \frac{H h}{22 b b}))$

式中：K为材料剪切屈服强度；b为筋宽；l为局部加载宽度；H为出现第二种局部加载状态区域坯料厚度；m为常剪切摩擦因子；σ_x为材料未流向筋型腔的腹板区内坯料X轴方向的应力，所述的腹板区内坯料同加载上模和下模同时接触；q为坯料内筋和腹板相交界面上的X轴方向的平均单位压力，所述的筋和腹板相交界面同筋型腔侧壁重合。式(1)中所采用的局部坐标系为简化界面中坯料所流入筋型腔的局部坐标系。In the formula: K is the shear yield strength of the material; b is the rib width; l is the local loading width; H is the blank thickness in the area where the second local loading state occurs; _m is the constant shear friction factor; Stress in the X-axis direction of the billet in the web area of the cavity, where the billet in the web area is in contact with the loaded upper die and lower die at the same time; q is the average unit of the X-axis direction on the interface between the inner rib of the billet and the web pressure, the intersecting interface between the rib and the web coincides with the side wall of the rib cavity. The local coordinate system used in formula (1) is the local coordinate system of the blank flowing into the rib cavity in the simplified interface.

成形过程中出现第二种局部加载状态区域坯料厚度H同加载上模行程s的关系由式(2)确定：In the forming process, the relationship between the thickness H of the blank in the area of the second local loading state and the stroke s of the loaded upper die is determined by formula (2):

H＝H₀-s (2)H＝H ₀ -s (2)

式中：H₀为出现第二种局部加载状态区域初始坯料厚度；s为加载上模行程；In the formula: H ₀ is the initial blank thickness in the area where the second local loading state appears; s is the stroke of the loaded upper die;

第三种局部加载状态，图2c所示；坯料下表面与下模具配合。下模具表面有筋条的成形型腔。所述不等厚坯料的表面为阶梯状，该阶梯的厚度差为ΔH。所述的第三种局部加载状态位于下模具的各筋条成形型腔之间，或者位于构件一端临近端头处的筋条成形型腔到所述下模该端的端面内侧壁之间，或者位于下模具的各筋条成形型腔之间和构件一端临近端头处的筋条成形型腔到所述下模该端的端面内侧壁之间；并且该区域坯料同下模完全接触，此时该区域的加载状态为第三种局部加载状态。The third partial loading state is shown in Figure 2c; the lower surface of the billet cooperates with the lower mold. A forming cavity with ribs on the surface of the lower mold. The surface of the unequal-thickness blank is stepped, and the thickness difference of the step is ΔH. The third local loading state is located between the rib forming cavities of the lower mold, or between the rib forming cavity at one end of the component near the end and the inner wall of the end face of the lower mold, or It is located between the rib forming cavities of the lower mold and between the rib forming cavity near the end of one end of the component and the inner side wall of the end face of the lower mold; and the blank in this area is in full contact with the lower mold, at this time The loading state of this area is the third partial loading state.

第三种局部加载状态下，局部加载宽度即为出现第三种局部加载状态区域内坯料同上模和下模都同时接触部分的宽度的二倍，该局部加载宽度l在局部加载阶段中随加载过程是动态变化的，出现第三种局部加载状态区域内的H和ΔH同上模行程之间是非线性相关的。第三种局部加载状态下的材料分流层处到筋型腔中心的距离x_k由式(5)确定：In the third partial loading state, the local loading width is twice the width of the part where the billet is in contact with the upper die and the lower die at the same time in the area where the third partial loading state occurs. The process is dynamic, and there is a nonlinear correlation between H and ΔH in the region of the third local loading state and the stroke of the upper die. The distance x _k from the material distribution layer to the center of the rib cavity under the third local loading state is determined by formula (5):

其中：in:

$q q = = 22 K K ((11 + + \frac{H h + + ΔH ΔH}{22 b b}))$

式中：K为材料剪切屈服强度；b为筋宽；l为局部加载宽度；ΔH为变厚度区的厚度差；H为变厚度区内未同加载上模接触的坯料厚度；m为常剪切摩擦因子；σ_x为材料未流向筋型腔的腹板区内坯料X轴方向的应力，所述的腹板区内坯料同加载上模和下模同时接触；q为坯料内筋和腹板相交界面上的X轴方向的平均单位压力，所述的筋和腹板相交界面同筋型腔侧壁重合。式(5)中所采用的局部坐标系为简化界面中坯料所流入筋型腔的局部坐标系。In the formula: K is the shear yield strength of the material; b is the rib width; l is the local loading width; ΔH is the thickness difference in the variable thickness area; Shear friction factor; σ _x is the stress in the X-axis direction of the blank in the web area where the material does not flow to the rib cavity, and the blank in the web area is in contact with the loaded upper die and lower die at the same time; q is the inner rib and The average unit pressure in the X-axis direction on the intersecting interface of the web, where the intersecting interface between the rib and the web coincides with the side wall of the rib cavity. The local coordinate system used in formula (5) is the local coordinate system of the blank flowing into the rib cavity in the simplified interface.

l＝l₀+b₁s+b₂s²(6)l＝l ₀ +b ₁ s+b ₂ s ² (6)

式中：A为l₀/b的比值，B为L/l₀的比值，C为H₀/b的比值，D为ΔH₀/H₀的比值；L为筋型腔中心到厚度H坯料区域的约束端之间距离的二倍；R为变厚度区的过渡条件，定义为宽度增量Δl和厚度差ΔH的比，即为Δl/ΔH，如图3所示；In the formula: A is the ratio of l ₀ /b, B is the ratio of L/l ₀ , C is the ratio of H ₀ /b, D is the ratio of ΔH ₀ /H ₀ ; L is the center of the rib cavity to the thickness H blank Twice the distance between the constrained ends of the region; R is the transition condition of the variable thickness region, defined as the ratio of the width increment Δl to the thickness difference ΔH, which is Δl/ΔH, as shown in Figure 3;

ΔH＝C₁-s-H (9)ΔH＝C ₁ -sH (9)

式中：C₁为ΔH₀加H₀之和；ΔH₀为初始厚度差；H₀为变厚度区内未同加载上模接触的初始坯料厚度；In the formula: C ₁ is the sum of ΔH ₀ plus H ₀ ; ΔH ₀ is the initial thickness difference; H ₀ is the initial blank thickness in the variable thickness zone that is not in contact with the loaded upper die;

令make

K₁＝L-l₀，K ₁ =Ll ₀ ,

K₂＝-b₁C₁-b+l₀，K ₂ =-b ₁ C ₁ -b+l ₀ ,

K₃＝-2(b₂C₁-b₁)，K ₃ =-2(b ₂ C ₁ -b ₁ ),

${K K}_{55} = = {22 b b}_{22} + + \frac{11}{22 mb mb},,$

${K K}_{88} = = {K K}_{55} + + \frac{{b b}_{22}}{22},,$

所述K₁～K₈均为(10)和式(11)中的简化项。The K ₁ to K ₈ are all simplified terms in (10) and formula (11).

根据初值条件用数值方法，求解式(10)、式(11)，本实施例中采用龙格-库塔法求解式(10)、式(11)。Formula (10) and formula (11) are solved by numerical method according to the initial value condition. In this embodiment, Runge-Kutta method is used to solve formula (10) and formula (11).

整体加载状态，图2d所示；坯料下表面与下模具配合。下模具表面有筋条的成形型腔。所述的整体加载状态位于下模具的各筋条成形型腔之间，或者位于构件一端临近端头处的筋条成形型腔到所述下模该端的端面内侧壁之间，或者位于下模具的各筋条成形型腔之间和构件一端临近端头处的筋条成形型腔到所述下模该端的端面内侧壁之间；并且该区域坯料同加载上模和下模完全接触，此时该区域的加载状态为整体加载状态。The overall loading state is shown in Figure 2d; the lower surface of the billet is matched with the lower mold. A forming cavity with ribs on the surface of the lower mold. The overall loading state is located between the rib forming cavities of the lower mold, or between the rib forming cavity at one end of the component near the end and the inner side wall of the end face of the lower mold, or between the rib forming cavity at the end of the lower mold. Between the rib forming cavities and between the rib forming cavity near the end of one end of the component and the inner side wall of the end face of the lower die; and the blank in this area is in complete contact with the loaded upper die and lower die, so The loading status of the region is the overall loading status.

当构件一端临近端头处的筋条成形型腔到所述下模该端的端面内侧壁之间为整体加载状态，则材料分流层处到该筋条成形型腔中心的距离x_k为所述下模该端的端面内侧壁到该筋条成形型腔中心的距离。When one end of the member is near the end of the rib forming cavity to the inner wall of the end face of the lower die, it is in an integral loading state, then the distance x _k from the material distribution layer to the center of the rib forming cavity is the The distance from the inner wall of the end face of the lower die to the center of the rib forming cavity.

H＝H₀-s (13)H＝H ₀ -s (13)

确定第一加载上模的最大行程，取计算步长为Δs。所述Δs的取值范围为0.01～0.1，本实施例中Δs＝0.05mm；To determine the maximum stroke of the first loaded upper die, take the calculation step as Δs. The value range of Δs is 0.01～0.1, and Δs=0.05mm in this embodiment;

在步长Δs内，根据步骤a，确定简化界面第1个筋型腔两侧的加载状态，根据加载状态、筋型腔和坯料的几何参数、摩擦条件分别计算流入简化界面的第1个筋型腔的材料体积；第1个筋型腔两侧坯料未同上模具和下模具接触，流入筋型腔材料体积为零；重复上述过程，根据步骤a，分别确定第2筋型腔两侧、第3筋型腔两侧、第4筋型腔两侧和第5筋型腔两侧的加载状态。根据加载状态、筋型腔和坯料的几何参数、摩擦条件分别计算流入简化界面的第2筋型腔、第3筋型腔、第4筋型腔和第5筋型腔的材料体积；第2筋型腔两侧坯料未同上模具和下模具接触，流入筋型腔材料体积为零；第3筋型腔两侧坯料未同上模具和下模具接触，流入筋型腔材料体积亦为零；第4筋型腔两侧坯料未同上模具和下模具接触，流入筋型腔材料体积亦为零；第5筋型腔两侧坯料未同上模具和下模具接触，流入筋型腔材料体积亦为零。至此完成一个步长Δs的计算。记录得到的每个筋型腔的材料体积，更新坯料几何参数和接触情况。Within the step length Δs, according to step a, determine the loading state on both sides of the cavity of the first rib on the simplified interface, and calculate the first rib flowing into the simplified interface according to the loading state, geometric parameters of the rib cavity and blank, and friction conditions The material volume of the cavity; the blanks on both sides of the first rib cavity are not in contact with the upper mold and the lower mold, and the volume of the material flowing into the rib cavity is zero; repeat the above process, and according to step a, respectively determine the two sides of the second rib cavity, Loading states on both sides of the third rib cavity, both sides of the fourth rib cavity and both sides of the fifth rib cavity. According to the loading state, the geometric parameters of the rib cavity and the blank, and the friction conditions, the material volumes of the second rib cavity, the third rib cavity, the fourth rib cavity and the fifth rib cavity flowing into the simplified interface are calculated respectively; the second The blanks on both sides of the rib cavity are not in contact with the upper mold and the lower mold, and the volume of the material flowing into the rib cavity is zero; the blanks on both sides of the third rib cavity are not in contact with the upper mold and the lower mold, and the volume of the material flowing into the rib cavity is also zero; The blanks on both sides of the 4th rib cavity are not in contact with the upper mold and the lower mold, and the volume of the material flowing into the rib cavity is also zero; the blanks on both sides of the 5th rib cavity are not in contact with the upper mold and the lower mold, and the volume of the material flowing into the rib cavity is also zero. . So far, the calculation of a step size Δs is completed. Record the material volume of each rib cavity, and update the blank geometric parameters and contact conditions.

根据步骤a，重复上述过程，继续确定各筋型腔两侧的加载状态并计算流入各筋型腔的材料体积。计算过程中，累加计算步长Δs，直至完成第一加载上模的最大行程，得到流入各筋型腔的材料体积。According to step a, repeat the above process, continue to determine the loading state on both sides of each rib cavity and calculate the volume of material flowing into each rib cavity. During the calculation process, the calculation step length Δs is accumulated until the maximum stroke of the first loaded upper mold is completed, and the volume of material flowing into each rib cavity is obtained.

确定第二加载上模的最大行程，取计算步长为Δs。所述Δs的取值范围为0.01～0.1，本实施例中Δs＝0.05mm；To determine the maximum stroke of the second loaded upper die, take the calculation step as Δs. The value range of Δs is 0.01～0.1, and Δs=0.05mm in this embodiment;

在步长Δs内，根据步骤a，确定简化界面第1个筋型腔两侧的加载状态，根据加载状态、筋型腔和坯料的几何参数、摩擦条件分别计算流入简化界面的第1个筋型腔的材料体积；第1个筋型腔两侧坯料未同上模具和下模具接触，流入筋型腔材料体积为零；重复上述过程，根据步骤a，分别确定第2筋型腔两侧、第3筋型腔两侧、第4筋型腔两侧和第5筋型腔两侧的加载状态。根据加载状态、筋型腔和坯料的几何参数、摩擦条件分别计算流入第二简化界面的第2筋型腔、第3筋型腔、第4筋型腔和第5筋型腔的材料体积；第2筋型腔两侧坯料未同上模具和下模具接触，流入筋型腔材料体积为零；第3筋型腔两侧坯料未同上模具和下模具接触，流入筋型腔材料体积亦为零；第4筋型腔两侧坯料未同上模具和下模具接触，流入筋型腔材料体积亦为零；第5筋型腔两侧坯料未同上模具和下模具接触，流入筋型腔材料体积亦为零。至此完成一个步长Δs的计算。记录得到的每个筋型腔的材料体积，更新坯料几何参数和接触情况。Within the step length Δs, according to step a, determine the loading state on both sides of the cavity of the first rib on the simplified interface, and calculate the first rib flowing into the simplified interface according to the loading state, geometric parameters of the rib cavity and blank, and friction conditions The material volume of the cavity; the blanks on both sides of the first rib cavity are not in contact with the upper mold and the lower mold, and the volume of the material flowing into the rib cavity is zero; repeat the above process, and according to step a, respectively determine the two sides of the second rib cavity, Loading states on both sides of the third rib cavity, both sides of the fourth rib cavity and both sides of the fifth rib cavity. Calculate the material volumes of the second rib cavity, the third rib cavity, the fourth rib cavity and the fifth rib cavity flowing into the second simplified interface according to the loading state, the geometric parameters of the rib cavity and the blank, and the friction conditions; The blanks on both sides of the second rib cavity are not in contact with the upper mold and the lower mold, and the volume of the material flowing into the rib cavity is zero; the blanks on both sides of the third rib cavity are not in contact with the upper mold and the lower mold, and the volume of the material flowing into the rib cavity is also zero. The blanks on both sides of the 4th rib cavity are not in contact with the upper mold and the lower mold, and the volume of the material flowing into the rib cavity is also zero; the blanks on both sides of the 5th rib cavity are not in contact with the upper mold and the lower mold, and the volume of the material flowing into the rib cavity is also zero. to zero. So far, the calculation of a step size Δs is completed. Record the material volume of each rib cavity, and update the blank geometric parameters and contact conditions.

根据步骤a，重复上述过程，继续确定各筋型腔两侧的加载状态并计算流入各筋型腔的材料体积。计算过程中，累加计算步长Δs，直至完成第二加载上模的最大行程，得到流入各筋型腔的材料体积。According to step a, repeat the above process, continue to determine the loading state on both sides of each rib cavity and calculate the volume of material flowing into each rib cavity. During the calculation process, the calculation step length Δs is accumulated until the maximum stroke of the second loaded upper mold is completed, and the volume of material flowing into each rib cavity is obtained.

$h h = = \frac{{V V}_{in in}^{tot tot}}{b b} - - - - - - ((1515))$

式中

整个成形过程中流入筋型腔的材料体积。In the formula

The volume of material that flows into the rib cavity throughout the forming process.

c.基于解析结果修改不等厚坯料，简化界面局部加载成形过程成形筋高的解析计算。根据解析结果修改不等厚坯料，并执行简化界面局部加载成形过程成形筋高的解析计算，当计算的成形筋高同设计要求筋高之间的高度差e_h的最大值max(e_h)小于10-15％时，停止修改坯料；获得简化界面所需的不等厚坯料形状。c. Based on the analytical results, the unequal-thickness billet is modified, and the analytical calculation of the forming rib height in the forming process of the interface local loading is simplified. Modify the unequal-thickness blank according to the analytical results, and perform _the analytical calculation of the forming rib height during the simplified interface local loading forming process. When the calculated forming rib height is the maximum height difference e _h between the designed rib height When it is less than 10-15%, stop modifying the blank; obtain the unequal thickness blank shape required for the simplified interface.

得到构件厚度方向中心线一侧的不等厚坯料。Obtain blanks of unequal thickness on one side of the center line in the thickness direction of the component.

b.构件上表面和下表面对称地分布有筋条，将a得到的不等厚坯料镜像，使坯料上表面和下表面对称地分布变厚度区，如图6所示，获得整体构件局部加载成形用三维基本不等厚坯料。b. Ribs are symmetrically distributed on the upper surface and lower surface of the member. Mirror the blank of unequal thickness obtained in a, so that the upper surface and lower surface of the blank are symmetrically distributed with variable thickness areas, as shown in Figure 6, and the local loading of the overall member is obtained. Three-dimensional basically unequal thickness blanks for forming.

步骤5，根据构件形状确定最终不等厚坯料。通过计算机数值模拟分析确定不等厚坯料。数值模拟分析步骤4中的基本不等厚坯料的成形过程。图7为构件局部加载成形过程的数值模拟模型，该数值模拟模型包括整体下模12、第一加载上模13、第二加载上模14和不等厚坯料15；第一加载步对第一加载上模13加载，第二加载步对第二加载上模14加载。两个加载步后弧形段端面未充满，根据三维数值模拟结果修改坯料形状，直至满足充填要求，得到最终的坯料。本实施例中经过一次修改获得满足充填要求的不等厚坯料，如图8所示。Step 5, determine the final unequal-thickness blank according to the shape of the component. The unequal thickness blanks are determined by computer numerical simulation analysis. Numerical simulation analysis of the forming process of the basic unequal thickness blank in step 4. Fig. 7 is the numerical simulation model of member local loading forming process, and this numerical simulation model comprises integral lower mold 12, the first loading upper mold 13, the second loading upper mold 14 and unequal thickness blank 15; Loading upper mold 13 loads, and the second loading step loads the second loading upper mold 14 . After two loading steps, the end face of the arc section is not filled, and the shape of the billet is modified according to the 3D numerical simulation results until the filling requirements are met, and the final billet is obtained. In this embodiment, blanks with different thicknesses meeting the filling requirements are obtained after one modification, as shown in FIG. 8 .

Claims

1. a definite three-dimensional frame component local loading and shaping is used the not method of uniform thickness blank, it is characterized in that, may further comprise the steps:

Step 1 is confirmed the interface of member; The interface by arc-shaped interface with form and run through two loading zones with the vertical straight line interface two parts of directions X; Described interface is parallel to the center line of member width

Step 2 is simplified the interface of confirming; Determined interface upper surface and lower surface all are distributed with a plurality of ribs symmetrically; Symmetrical center line one side with the member thickness direction is a simplifying interface, and each rib in this simplifying interface is designated as i muscle, i=1～n respectively; The rib of shaping simplifying interface adopts local loading and shaping, and the mould district location is the center of subregion muscle in the loading; Confirm that a rib in the 2nd muscle～n-1 muscle is the subregion muscle;

Step 3 confirms that the simplifying interface place needs not uniform thickness blank shape; Realize confirming that through simplifying interface being carried out rapid analysis the simplifying interface place needs not uniform thickness blank shape; When simplifying interface is done rapid analysis, get one not the uniform thickness blank and confirm the blank shape of simplifying interface according to initial blank as initial blank; Simplifying interface is done in the rapid analysis, three kinds of local loading states and a kind of whole stress state are arranged; Said three kinds of local loading states are respectively; Because first kind of local loading state that mould part load to form, the second kind of local loading state that forms by the different depth of different webs district mould, and the third local loading state that causes by the step-thickness difference Δ H of the not step-like surface existence of uniform thickness blank; Each simplifying interface is being carried out rapid analysis, each muscle die cavity place of whole counterdie to set up local rectangular coordinate system; The Y coordinate of said local rectangular coordinate system is positioned at the symmetrical centre of muscle die cavity width of living in, and the origin of coordinates of each local rectangular coordinate system is positioned at the intersection point place of this Y coordinate and X coordinate;

Simplifying interface is carried out rapid analysis, confirm the blank shape of simplifying interface; Detailed process:

A. confirm shunting layer position and muscle die cavity filler volume calculation formula according to the stress state in the simplifying interface local loading and shaping;

Need not to wait the geometry characteristic of thick stock, mould according to the simplifying interface place, can three kinds of local loading states of appearance and a kind of whole stress state in the local loading and shaping process;

First kind of local loading state; The blank lower surface cooperates with bed die; Bottom mold surface has the shaping die cavity of rib;

Described first kind of local loading state arrives between the branch mould position near the complete muscle die cavity of minute first of mould position in loading zone; Blank in this zone contacts with loading upper die and lower die fully, and stress state that at this moment should the zone is first kind of local loading state;

Under first kind of local loading state; The local loading width is and occurs in first kind of local loading state region near minute complete muscle die cavity of first of mould position center two times to distance between the subregion muscle cavity lateral, and said subregion muscle cavity lateral is the sidewall that first kind of local loading state one side appears in this muscle die cavity; Local loading width l does not change in the stage in local loading, and occurring between the same line journey of sotck thinkness H in first kind of local loading state region is linear relationship; Adopt computing formula (1) calculate first kind of local loading state material shunting layer place down arrive muscle die cavity center apart from x _k:

\{\begin{matrix} x_{k} = \frac{b}{2} & σ_{x} |_{x = b / 2} \leq q \\ x_{k} = \frac{1}{4} (l + b - \frac{H^{2}}{mb}) & σ_{x} |_{x = b / 2} > q \end{matrix} --- (1)

Wherein:

σ_{x} |_{x = b / 2} = 2 K + \frac{mK}{H} (l - b)

q = 2 K (1 + \frac{H}{2 b})

In the formula: K is the material shear yield strength; B is that muscle is wide; L is the local loading width; H is for first kind of local loading state region sotck thinkness occurring; M is the normal shearing friction factor; σ _xDo not flow to the stress of blank X-direction in the web district of muscle die cavity for material, blank contacts with loading upper die and lower die simultaneously in the described web district; Q is the average unit pressure of the X-direction on interior muscle of blank and the web intersection interface, and described muscle and web intersection interface overlap with the muscle cavity lateral; The local coordinate system that is adopted in the formula (1) by blank in the simplifying interface the local coordinate system of inflow muscle die cavity;

Occurring first kind of local loading state region sotck thinkness H in the forming process is confirmed by formula (2) with the relation that loads patrix stroke s:

H＝H ₀-s (2)

In the formula: H ₀For first kind of local loading state region initial blank thickness occurring; S is for loading the patrix stroke;

Flow into the material volume V of muscle die cavity _InConfirm by formula (3):

V_{in} = {&Integral;}_{s_{1}}^{s_{2}} x_{k} (s) ds - - - (3)

Flow into the material volume V of subregion muscle die cavity _OutConfirm by formula (4):

V_{out} = {&Integral;}_{s_{1}}^{s_{2}} [\frac{l}{2} - x_{k} (s)] ds - - - (4)

Second kind of local loading state; The blank lower surface cooperates with bed die; Bottom mold surface has the shaping die cavity of rib; The both sides web thickness of muscle changes; In loading and shaping; Blank between the adjacent muscle die cavity with a side of this muscle die cavity contacts with loading upper die and lower die fully; And the blank between the adjacent muscle die cavity with opposite side of said this muscle die cavity does not contact with loading upper die and lower die fully, and the stress state between the adjacent muscle die cavity with a said side of said this muscle die cavity this moment is second kind of local loading state;

Under second kind of local loading state; The local loading width is said this muscle cavity lateral two times to distance between the adjacent muscle die cavity of this side center; Local loading width l does not change in the stage in local loading, and occurring between the same line journey of sotck thinkness H in second kind of local loading state region is linear relationship; Said muscle cavity lateral is the sidewall that second kind of local loading state one side appears in this muscle die cavity; Adopt formula (1) calculate second kind of local loading state material shunting layer place down arrive muscle die cavity center apart from x _kH in the formula (1) is for second kind of local loading state region sotck thinkness occurring;

Occurring second kind of local loading state region sotck thinkness H in the forming process is confirmed by formula (2) with the relation that loads patrix stroke s: the H in the formula (2) ₀For second kind of local loading state region initial blank thickness occurring;

Flow into the material volume V of muscle die cavity _InConfirm by formula (3);

The third local loading state; The blank lower surface cooperates with bed die; Bottom mold surface has the shaping die cavity of rib; The surface of said not uniform thickness blank is stepped, and the thickness difference of this ladder is Δ H; Described the third local loading state is between each rib shaping die cavity of bed die; Perhaps between the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie, perhaps between each rib shaping die cavity of bed die and the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie between; And should contact fully with counterdie by the zone blank, the stress state that this moment should the zone is the third local loading state;

Under the third local loading state; The local loading width is and blank occurs in the third local loading state region with all simultaneously two times of the width of contact portion of upper die and lower die; This local loading width l is dynamic change with loading procedure in local loading in the stage, and occurring between H and the same line journey of Δ H in the third local loading state region is nonlinear correlation; Material shunting layer place under the third local loading state to muscle die cavity center apart from x _kConfirm by formula (5):

\{\begin{matrix} x_{k} = \frac{b}{2} & σ_{x} |_{x = b / 2} \leq q \\ x_{k} = \frac{1}{4} (l + b) - \frac{ΔH}{2 m} (1 + \frac{H + ΔH}{2 b}) & σ_{x} |_{x = b / 2} > q \end{matrix} --- (5)

Wherein:

σ_{x} |_{x = b / 2} = \frac{mK}{ΔH} (l - b)

q = 2 K (1 + \frac{H + ΔH}{2 b})

In the formula: K is the material shear yield strength; B is that muscle is wide; L is the local loading width; Δ H is for becoming the thickness difference of caliper zones; H is for becoming in the caliper zones not with the sotck thinkness that loads upper mould contact; M is the normal shearing friction factor; σ _xFor material does not flow to the stress of blank X-direction in the muscle die cavity web district, blank contacts with loading upper die and lower die simultaneously in the described web district; Q is the average unit pressure of the X-direction on interior muscle of blank and the web intersection interface, and described muscle and web intersection interface overlap with the muscle cavity lateral; The local coordinate system that is adopted in the formula (5) by blank in the simplifying interface the local coordinate system of inflow muscle die cavity;

In the forming process, the dynamic change of local loading width l is confirmed by formula (6):

l＝l ₀+b ₁s+b ₂s ²(6)

L in the formula ₀Be initial local loading width; S is for loading the patrix stroke; b ₁Be coefficient once; b ₂Be the quadratic term coefficient; b ₁And b ₂Confirm by formula (7) and formula (8) respectively:

ln(b ₁)＝1.16941+0.03880A-0.13668B-0.33010C-0.47077D-0.04376R+0.17274lnA+0.73480lnB-0.39029lnC+0.64892lnR (7)

ln(b ₂)＝-1.01970-0.03751A+0.74384B-0.04876C-0.22359D+1.19454R+0.94165lnA-3.74272lnB-0.45123lnC-1.50094lnR (8)

A is l in the formula ₀The ratio of/b, B are L/l ₀Ratio, C is H ₀The ratio of/b, D are Δ H ₀/ H ₀Ratio;

L is muscle die cavity center two times to distance between the restrained end of thickness H biscuit area; R is defined as the ratio of width increment Delta l and thickness difference Δ H for becoming the transition condition of caliper zones, is Δ l/ Δ H;

The thickness difference Δ H that becomes caliper zones in the forming process is confirmed by formula (9):

ΔH＝C ₁-s-H (9)

In the formula: C1 is Δ H ₀Add H ₀Sum; Δ H ₀For original depth poor; H ₀For becoming in the caliper zones not with the initial blank thickness that loads upper mould contact;

Order

K ₁＝L-l ₀，

K ₂＝-b ₁C ₁-b+l ₀，

K ₃＝-2(b ₂C ₁-b ₁)，

K_{4} = b_{1} - \frac{1}{m} - \frac{C_{1}}{2 mb},

K_{5} = {2 b}_{2} + \frac{1}{2 mb},

K_{6} = - C_{1} K_{4} + \frac{1}{2} (l_{0} - b),

K_{7} = \frac{b_{1}}{2} + K_{4} - C_{1} K_{5},

K_{8} = K_{5} + \frac{b_{2}}{2},

Said K ₁～K ₈Be the simplification item in (10) and the formula (11);

Flow into the material volume V of muscle die cavity _InConfirm by formula (10) or formula (11) differential equation group:

Work as σ _x| _X=b/2Have during≤q:

\{\begin{matrix} (K_{1} - b_{1} s - b_{2} s^{2}) \frac{DH}{Ds} - (b_{1} + {2 b}_{2} s) H = K_{2} + K_{3} s + {3 b}_{2} s^{2} \\ \frac{{DV}_{In}}{Ds} = \frac{b}{2} \end{matrix} - - - (10)

Work as σ _x| _X=b/2Have during＞q:

\{\begin{matrix} (K_{1} - b_{1} s - b_{2} s^{2}) \frac{DH}{Ds} - (K_{4} + K_{5} s) H = K_{6} + K_{7} s + K_{8} s^{2} \\ \frac{{DV}_{In}}{Ds} = \frac{1}{4} (l_{0} + b + b_{1} s + b_{2} s^{2}) - \frac{C_{1} - s - H}{2 m} (1 + \frac{C_{1} - s}{2 b}) \end{matrix} - - - (11)

Can find the solution formula (10), formula (11) with numerical method according to initial condition;

Whole stress state; The blank lower surface cooperates with bed die; Bottom mold surface has the shaping die cavity of rib; Described whole stress state is between each rib shaping die cavity of bed die; Perhaps between the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie, perhaps between each rib shaping die cavity of bed die and the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie between; And should the zone blank contact fully with loading upper die and lower die, the stress state that this moment should the zone is whole stress state;

When the rib shaping die cavity at member one end proximity head place should be whole stress state between end face madial wall of end to said counterdie, then material shunting layer place arrive this rib shaping die cavity center apart from x _kFor said counterdie is somebody's turn to do the distance of the end face madial wall of end to this rib shaping die cavity center;

When being whole stress state between i muscle die cavity and i+1 the muscle die cavity, then material shunting layer place to i muscle die cavity center apart from x _kConfirm by formula (12):

x_{k} = \frac{a_{i, i + 1}}{2} + \frac{b_{i} - b_{i + 1}}{4} + \frac{H^{2}}{4 m} (\frac{1}{b_{i + 1}} - \frac{1}{b_{i}}) - - - (12)

In the formula: a _{I, i+1}It is the distance between i muscle die cavity center and i+1 the muscle die cavity center; b _iThe muscle that is i muscle is wide; b _I+1The muscle that is i+1 muscle is wide; H is for whole stress state zone sotck thinkness occurring; M is the normal shearing friction factor;

Occurring whole stress state zone sotck thinkness H in the forming process is confirmed by formula (13) with the relation that loads patrix stroke s:

H＝H ₀-s (13)

In the formula: H ₀For whole stress state zone initial blank thickness occurring; S is for loading the patrix stroke;

Flow into the material volume V of muscle die cavity _InConfirm by formula (14):

V_{in} = {&Integral;}_{s_{1}}^{s_{2}} x_{k} (s) ds - - - (14)

B. the high analytical Calculation of simplifying interface local loading and shaping process shaping muscle;

First loads the material volume that flows into each muscle die cavity of simplifying interface in the step calculates:

Confirm that first loads the range of patrix, get and calculate step delta s that the span of said Δ s is 0.01～0.1; In step delta s,, confirm the stress state of i muscle die cavity of simplifying interface both sides, i=1～n according to step a; Calculate the material volume of i the muscle die cavity that flows into simplifying interface respectively according to geometric parameter, the friction condition of stress state, muscle die cavity and blank; I muscle die cavity both sides blank do not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; So far accomplish the calculating of a step delta s; The material volume of each muscle die cavity that record obtains upgrades the blank geometric parameter and contacts situation;

According to step a, repeat said process, continue to confirm the stress state of each muscle die cavity both sides and calculate the material volume that flows into each muscle die cavity; Said continuation is confirmed the stress state of each muscle die cavity both sides and is calculated in the material volume process that flows into each muscle die cavity, and accumulation calculating step delta s until the range of accomplishing the first loading patrix, obtains flowing into the material volume of each muscle die cavity;

After accomplishing the calculating in the first loading step, on the blank shape basis of subregion shaping rib, carry out second and load the material volume calculating that flows into each muscle die cavity of simplifying interface in the step:

Confirm that second loads the range of patrix, get and calculate step delta s that the span of said Δ s is 0.01～0.1; In step delta s,, confirm the stress state of i muscle die cavity of simplifying interface both sides, i=1～n according to step a; Calculate the material volume of i the muscle die cavity that flows into simplifying interface respectively according to geometric parameter, the friction condition of stress state, muscle die cavity and blank; I muscle die cavity both sides blank do not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; So far accomplish the calculating of a step delta s; The material volume of each muscle die cavity that record obtains upgrades the blank geometric parameter and contacts situation;

According to step a, repeat said process, continue to confirm the stress state of each muscle die cavity both sides and calculate the material volume that flows into each muscle die cavity; The stress state and the calculating that continue definite each muscle die cavity both sides flow in the material volume process of each muscle die cavity, and accumulation calculating step delta s until the range of accomplishing the second loading patrix, obtains flowing into the material volume of each muscle die cavity;

Accomplish two calculating that load the step, the high h of shaping muscle of each muscle is confirmed by formula (15) respectively in the simplifying interface:

h = \frac{V_{in}^{tot}}{b} - - - (15)

Flow into the material volume of muscle die cavity in the formula in whole forming process;

C. revise not uniform thickness blank based on analysis result, the high analytical Calculation of simplifying interface local loading and shaping process shaping muscle; Revise not uniform thickness blank according to analysis result, and carry out the high analytical Calculation of simplifying interface local loading and shaping process shaping muscle, when the shaping muscle height that calculates with the difference in height e between the designing requirement muscle height _hMaximum max (e _h) during less than 10-15%, stop to revise blank; Obtain the required not uniform thickness blank shape of simplifying interface;

Step 4 is confirmed basically not uniform thickness blank shape;

A. according to the not uniform thickness blank shape on the simplifying interface of step 3 acquisition, confirm not uniform thickness blank of three-dimensional, simultaneously according to the following caliper zones setting principle that becomes:

Become caliper zones transition condition R＞1;

Blank becomes caliper zones and should avoid being arranged near the branch mould position and near the muscle die cavity;

If near muscle die cavity or mould subregion, the change caliper zones is set, need to adopt bigger transition condition, i.e. R＞2;

Obtain the not uniform thickness blank of member thickness direction center line one side;

B. member upper surface and lower surface are distributed with rib symmetrically, with the not uniform thickness blank mirror image that a obtains, make blank upper surface and the lower surface change caliper zones that distributes symmetrically, obtain the integrated member local loading and shaping with three-dimensional uniform thickness blank not basically;

Step 5 is confirmed finally not uniform thickness blank according to the member shape; Confirm not uniform thickness blank through the Computer Numerical Simulation analysis; The forming process of uniform thickness blank not basically in the numerical simulation analysis step 4; First loads the step to the first loading patrix loading, and the second loading step loaded the patrix loading to second; Two load the step back if member shape unmet filling requirement is then revised blank shape according to the three-dimensional numerical value analog result, until the not uniform thickness blank that is met the filling requirement.