JP2019123002A - Deformation analysis method for material to be pressed - Google Patents

Abstract

To provide a deformation analysis method for a material to be pressed capable of performing a deformation analysis at the time of press forming in short time.SOLUTION: A deformation analysis method for a material to be pressed as the method for analyzing deformation of the material to be pressed when performing mold-opening from a state of performing mold-clamping of the material to be pressed with a press mold includes a correlation acquisition step S41 of acquiring correlation between a stress distribution generated on the material to be pressed when applying a heat load to the material to be pressed and the heat load, a heat load applying step S42 of substituting the stress distribution generated on the material to be pressed in a mold-clamping state with the heat load based on correlation to apply the heat load to an analytic model 10 of the material to be pressed and a deformation analysis step S43 of analyzing the deformation of the analysis model 10 of the material to be pressed when turning to the mold-opening state from the mold-clamping state.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method of analyzing deformation of a material to be pressed.

  For example, in the process of manufacturing panel-like parts such as steel plates used in automobile bodies, press forming is generally used. As described above, a part obtained by press molding (hereinafter referred to as a pressed part) usually causes a considerable amount of springback at the time of mold opening due to the residual stress generated at the time of press molding (particularly at the time of mold clamping). Since this spring back can cause dimensional accuracy defects, deformation during press molding is predicted in advance by numerical analysis using FEM (finite element method) or the like, and measures are considered (for example, Patent Document 1). reference).

JP, 2013-198927, A

  By the way, when analyzing the deformation at the time of press molding as described above, depending on the conditions, the material to be pressed as an analysis condition so that a predetermined stress distribution (residual stress distribution) is generated in the clamped material in a clamped state. It may be desirable to apply a predetermined stress distribution to the In this case, as a method of applying a predetermined stress distribution to an analysis model of a material to be pressed, a method of applying a displacement or a load is generally used, but in the case of a displacement or a load, in addition to the size, the direction Since it is also necessary to specify information, there is a problem that the amount of calculation becomes enormous.

  In view of the above-mentioned circumstances, in the present invention, it is a technical problem to be solved that deformation analysis at the time of press molding can be performed in a short time.

  The solution to the above problem is achieved by the deformation analysis method of a material to be pressed according to the present invention. That is, this analysis method is a method of analyzing the deformation of the material to be pressed when the material to be pressed is opened with the press mold, and when the thermal load is applied to the material to be pressed Based on the correlation acquisition step of acquiring the correlation between the stress distribution occurring in the material and the thermal load and the correlation, the stress distribution occurring in the material to be pressed in the clamped state is replaced with the thermal load to obtain an analysis model of the material to be pressed It is characterized in that it comprises a thermal load application step to be applied, and a deformation analysis step of analyzing deformation of an analysis model of the material to be pressed when the mold is in a mold open state from the mold clamping state.

  As described above, in the analysis method according to the present invention, the stress distribution generated based on factors other than heat, such as the press load, in the clamping state of press forming is replaced by the heat load on the analysis to analyze the pressed material Added to the model. When a thermal load is applied to the material to be pressed in this type of press molding, that is, when heat is applied in the mold clamped state, a certain correlation is recognized between the stress distribution generated in the material to be pressed and the thermal load. Be Therefore, based on this correlation, a predetermined thermal load is applied to the analysis model of the material to be pressed so that the desired stress distribution to be applied is generated in the material to be pressed in the clamped state. As a result, since it is sufficient to specify only the magnitude of heat, the amount of calculation can be significantly reduced compared to the prior art. Therefore, accurate deformation analysis can be performed while shortening the time required for deformation analysis of the material to be pressed.

  Further, in the deformation analysis method of the material to be pressed according to the present invention, in the correlation acquisition step, the stress distribution generated in the basic shape model when the thermal load is applied to the basic shape model of the material to be pressed is calculated by analysis The correlation between the stress distribution and the thermal load may be acquired.

  Thus, if it is stress distribution at the time of giving a thermal load to a basic shape model of a material to be pressed, it can ask for by simple analysis. Therefore, the correlation between the stress distribution and the thermal load described above can be acquired in a short time, and the time required for the deformation analysis of the material to be pressed can be further shortened. Moreover, since the above-mentioned analysis is an analysis made for the purpose of acquiring the correlation (the tendency) between the stress distribution and the thermal load, it is not an analysis model that faithfully reproduces the shape of the material to be pressed (actually There is no particular problem in terms of analysis accuracy, even if the model is more simplified than the shape of.

  In the deformation analysis method of the material to be pressed according to the present invention, the analysis model of the material to be pressed may be formed by a solid model having a plurality of solid elements in the thickness direction.

  Thus, by forming an analysis model of the material to be pressed with a solid model having a plurality of solid elements in its thickness direction, for example, a thermal load is applied to the solid element forming the surface of the material to be pressed, The stress distribution generated in the material to be pressed in the tightened state can be reproduced. Therefore, accurate stress distribution can be reproduced in the thickness direction of the material to be pressed, which makes it possible to further improve the accuracy of the deformation analysis. Of course, in the present invention, since the stress distribution generated in the material to be pressed due to the mold clamping is replaced by the thermal load, even in the case of using a solid model having a plurality of solid elements in the thickness direction, Accurate deformation analysis can be performed while suppressing an increase in calculation time.

  As described above, according to the present invention, deformation analysis at the time of press molding can be performed in a short time.

It is a flowchart which shows the flow of the deformation factor analysis method of the press part which concerns on one Embodiment of this invention, and a design method. It is a flowchart which shows the flow of the deformation | transformation analysis method of the press components concerning one Embodiment of this invention. (A) is a full-sized model of a pressed part to be subjected to the deformation analysis, and (b) to (d) are specific examples of deformation modes which can be generated in the pressed part by press forming. It is the figure which enumerated the specific example of the deformation mode which may arise in the press part of predetermined shape by press molding. It is the figure which enumerated the specific example of the factor stress distribution used as the generating factor of each deformation mode. It is the figure which showed typically an example of the factor stress distribution which becomes a generation factor of each deformation mode. It is a principal part perspective view which concerns on an example at the time of producing the full size model shown in FIG. 2 by a solid element. It is a principal part front view which shows the state which applied the factor stress distribution with the thermal load with respect to the full size model shown in FIG. It is a graph which shows correlation with stress distribution and heat load. It is a graph which shows the contribution of each generating factor to one deformation mode. It is a graph which shows the contribution of each generating factor to other deformation modes. It is a schematic diagram which shows the procedure of the stress analysis method at the time of press molding conventionally performed.

  Hereinafter, the contents of a method of analyzing deformation factors of a pressed part according to an embodiment of the present invention and a method of designing a pressed part using the analysis result will be described based on the drawings.

  FIG. 1 shows a procedure of a method of designing a pressed part according to the present embodiment. As shown in FIG. 3, in this design method, a full-size model creation step S1 for creating a full-size model of a pressed part, a deformation mode setting step S2 for setting a plurality of deformation modes that may occur in the pressed part, and a deformation mode Factor stress setting step S3 for setting the factor stress that becomes the generation factor of the deformation, deformation analysis step S4 for applying the factor stress independently to the full size model, and performing deformation analysis of the full size model at that time, deformation analysis step S4 An evaluation step for evaluating the influence of the generation factor on each deformation mode based on the deformation analysis result obtained in step b, where a contribution degree specifying step S5 for specifying the number of generation factors contributing to each deformation mode and the contribution degree thereof; The influence of the cause of generation for each deformation mode, in this case the contribution of each cause of generation to each deformation mode, is reflected in the full-size model to design a pressed part. And a degree reflecting step S6.

  In addition, as shown in FIG. 2, in the deformation analysis step S4, a correlation acquisition step S41 for acquiring the correlation between the stress distribution generated in the pressed part when the thermal load is applied to the pressed part and the thermal load, and the correlation Based on the heat load application step S42 of replacing the stress distribution generated in the press part in the mold clamping state with the thermal load and applying to the full size model of the press part, and the press parts when the mold clamping state is changed to the mold opening state And a deformation analysis step S43 for analyzing the deformation of the true size model. In addition, the press part here corresponds to the to-be-pressed material which concerns on this invention, and the full size model of a press part corresponds to the analysis model of the to-be-pressed material which concerns on this invention. Hereinafter, each step will be described in order.

(S1) Exact Model Creation Step In this step, an exact model of a pressed part to be subjected to deformation analysis is created. In the present embodiment, the pressed part is formed of a plate-like member, and has, for example, a cross-sectional hat shape as shown in FIG. 3 (a). Therefore, a three-dimensional analysis model is created so that the full-sized model 10 of the pressed part also has a cross-sectional hat shape. In addition, the full size model 10 of a press part here shall mean the analysis model which has the drawing dimension of the press part in the time before the start of this analysis method.

(S2) Deformation Mode Setting Step In this step, a plurality of deformation modes which can be generated in the press part by press molding are set. Here, when selecting a specific deformation mode, past findings or data concerning stress forming of pressed parts of the same shape, different materials or similar shapes (including simple shapes) (stress analysis, basic experiment It is good to carry out based on the academic verification result concerning the same press molding and the thing obtained by trial production etc.) and the same press molding. For example, as shown in FIG. 3A, as a deformation mode that can occur when press-forming a press part having a cross-sectional hat shape, as shown in FIG. Mode M1), opening of vertical wall portion 11 (second deformation mode M2), warping of upper wall portion 12 (third deformation mode M3), splashing of flange portion 14 (fourth deformation mode M4), etc. It can be mentioned.

  In addition, the curvature of the vertical wall part 11 here means the mode which produces a bending deformation in the direction in which the vertical wall parts 11 on either side mutually distances, as shown, for example in FIG.3 (b). Further, as shown in FIG. 3C, for example, the opening of the vertical wall portion 11 is in the direction in which the angle between the inner surface of the vertical wall portion 11 and the inner surface of the upper wall portion 12 increases. This means a mode in which the corner (first corner 13) connecting the wall 12 is deformed. The warp of the upper wall portion 12 means, for example, a mode in which the upper wall portion 12 connected to the left and right vertical wall portions 11 causes bending deformation along the longitudinal direction, as shown in FIG. 3D.

  Of course, depending on the shape of the press part having a hat-shaped cross section, for example, although not shown, other deformation modes such as twisting (twisting around a virtual axis along the longitudinal direction) and bending of the entire press part are further set. May be

(S3) Factorial stress setting step In this step, factorial stress which is a generation factor of each deformation mode, here, factorial stress distribution is set for each deformation mode. Here, when setting the factor stress distribution that is a specific generation factor, as in the deformation mode, past knowledge or data concerning press forming of pressed parts of the same shape, different materials or similar shapes, and the same material, It is good to do based on the academic verification result concerning the same press molding. For example, as shown in FIG. 4, when a plurality of deformation modes M1 to M4 that can occur when a press part having a cross-sectional hat shape is formed by pressing, the generation factor F1 of each deformation mode M1 (M2 to M4) The factor stress distribution which becomes (F2 to F5) can be set. Specifically, as shown in FIG. 5, for the first deformation mode M1 related to the warping of the vertical wall portion 11, the front / back stress difference of the vertical wall portion 11 is the first occurrence factor F1 (factor stress distribution Can be mentioned as In addition, for the second deformation mode M2 related to the opening of the vertical wall portion 11, the front / back stress difference of the first corner portion 13 can be mentioned as a second generation factor F2 (factorial stress distribution). In addition, for the third deformation mode M3 related to the warpage of the upper wall portion 12, third and fourth stress differences between the upper wall portion 12 and the flange portion 14 are respectively calculated. Cause factor of F3 and F4
It can be mentioned as (factorial stress distribution). In addition, for the fourth deformation mode M4 related to the splash of the flange portion 14, the front / back stress difference of the corner portion (second corner portion 15) connecting the vertical wall portion 11 and the flange portion 14 is generated fifth It can be mentioned as a factor F5 (factorial stress distribution).

  Here, the front / back stress difference (the first generation factor F1) of the vertical wall portion 11 is, for example, shown in FIG. 6 that the outer surface 11a side of the vertical wall portion 11 with respect to the neutral axis 11c The stress σ + means a stress distribution which causes a compressive stress σ− in the longitudinal direction on the inner surface 11b side. The same stress distribution means the other generation factors F2 to F5.

  Of course, as described above, when further setting other deformation modes such as twisting or bending of the entire press part to the press part having a cross-sectional hat shape, the factor stress which causes generation of these other deformation modes ( The factor stress distribution) may be set individually.

(S4) Deformation Analysis Step In this step, deformation analysis of the true-size model 10 when the factor stress (factor stress distribution) that is a generation factor of each deformation mode is independently applied to the true-size model 10 is performed. For example, when the plurality of deformation modes M1 to M4 shown in FIG. 4 and the factor stress distribution (generation factors F1 to F5) shown in FIG. 5 are set, the factor that becomes the first generation factor F1 with respect to the full size model 10 The stress distribution (see FIG. 6) is independently applied to analyze the deformation of the full-sized model 10 at that time (deformation analysis for the first deformation mode M1). Also, the factor stress distribution (see FIG. 5) serving as the second occurrence factor F2 is independently imparted to the full size model 10, and the deformation of the full size model 10 at that time is analyzed (second deformation mode M2 Deformation analysis). In addition, factorial stress distributions (see FIG. 5) serving as the third and fourth occurrence factors F3 and F4 are individually applied to the full size model 10, and the deformation of the full size model 10 at that time is analyzed All are deformation analysis for the third deformation mode M3). In addition, the factor stress distribution (see FIG. 5) serving as the fifth generation factor F5 is independently imparted to the full size model 10, and the deformation of the full size model 10 at that time is analyzed (fourth deformation mode M4 Deformation analysis). The point is that the deformation analysis of the true-size model 10 is performed by the number of deformation modes set in step S2 (when the number of generation causes can be set for one deformation mode, the number of generation causes).

  Here, in the present embodiment, the factor stress distribution is applied to the true size model 10 by a thermal load (thermal load application step S42). The factor stress distribution referred to here corresponds to the stress distribution according to the present invention. Further, in this case, as shown in FIG. 7, for example, the full size model 10 as an analysis model is formed by a solid model having a plurality of solid elements 21 to 23 in the thickness direction, and a specific solid element (here, By applying a thermal load to the solid elements 22 and 23) on the surface side in the thickness direction that forms the surface of the pressed part, the factor stress distribution that is the generation factor F1 to F5 of each of the deformation modes M1 to M4 is reproduced. At this time, a thermal load may be applied in a state in which the solid element 21 located on the center side in the thickness direction of the true-size model 10 is restrained.

  Specifically, as shown in FIG. 8, in the press-clamped state, positive heat 24 is applied (heated) to the nodes 22a of the solid element 22 located on the front and back sides of the full-size model 10 By applying (cooling) negative heat 25 to the nodal point 23a of the solid element 23 located on the other side of the front and back sides, thereby applying a desired thermal load to a predetermined portion of the full size model 10, and press forming It is possible to reproduce a predetermined stress distribution (factorial stress distribution) in the clamped state of. For example, solid elements 22 located on the front and back sides constitute the inner surface 11b (see FIG. 6) of the vertical wall 11, and solid elements 23 located on the other side are the outer surface 11a of the vertical wall 11 (FIG. 6). 6) by applying positive heat 24 to the nodes 22a of the solid element 22 and applying negative heat 25 to the nodes 23a of the solid element 23, the stress distribution shown in FIG. (Factor stress distribution), that is, a factor stress distribution (difference between front and back stress of the vertical wall portion 11) which is the first generation factor F1 of the first deformation mode M1 shown in FIG. 3B can be provided. When the solid element 21 on the center side in the thickness direction is constrained, the above-described factor stress distribution is applied while the node 21a of the solid element 21 is also constrained. After giving the factorial stress distribution in this manner, the deformation of the true-size model 10 when the mold clamping state is changed to the mold opening state is analyzed (deformation analysis step S43).

  The magnitude of heat 24 and 25 (thermal load) applied at this time was determined by applying thermal load to an analysis model (basic shape model) having a shape obtained by further simplifying the true size model 10 or the true size model 10 in advance. The correlation between the stress distribution at that time and the thermal load is acquired by analysis (correlation acquisition step S41), and the correlation can be set based on the correlation. As shown in FIG. 9, a linear correlation tends to be recognized between the stress distribution and the thermal load when a thermal load is applied to a press part composed of a plate-like member in this type of press molding. Because of this, it is possible to replace the easily assumed factor stress distribution with a thermal load.

(S5) Contribution Degree Specifying Step In this step, based on the deformation analysis result of the full size model 10 obtained in the deformation analysis step S4, the number of generation factors contributing to each deformation mode and each generation factor to each deformation mode Identify the degree of contribution. For example, in the deformation analysis step S4, when the factor stress distribution serving as the generation factor F1 of the first deformation mode M1 shown in FIG. 5 is applied to the full size model 10 in the mold clamped state, the full size model 10 in the mold opened state is While the first deformation mode M1 (primary deformation mode) occurs, another deformation mode (for example, a secondary deformation mode such as the second deformation mode M2), and in some cases still another deformation mode (for example, the third deformation mode) A third-order deformation mode (such as deformation mode M3) may occur. In this case, the degree of contribution of the generation factors (for example, the first to fourth generation factors F1 to F4) of the deformation modes M1 to M3 is specified from the deformation amounts of the full size model 10 according to the deformation modes M1 to M3. Specifically, one deformation analysis result obtained by analysis is decomposed into deformation amounts for each of the deformation modes M1 to M3, and the corresponding generation factors F1 to F4 are calculated based on the size of the decomposed deformation amount. Calculate the degree of contribution.

  Similarly, with regard to the deformation analysis result when applying the factor stress distribution that causes the other deformation modes M2 to M4 to be the generation factors F2 to F5 to the full size model 10, the number of generation causes of the deformation mode in which the generation is recognized, And their contributions. In this way, with respect to the deformation analysis result of the true-size model 10 obtained for all the generation factors, the number of generation factors contributing to the deformation and the contribution thereof are specified. For example, in the deformation analysis result for one deformation mode shown in FIG. 10, the contribution degree of the generation factor A is the highest, and the contribution degree of the generation factor B is relatively low. On the other hand, in the deformation analysis results for the other deformation modes shown in FIG. 11, it can be seen that the contribution degree of the generation factor B is the highest, followed by the contribution degree of the generation factor A. From this, it can be clearly understood that the generation factor of one deformation mode contributes as the generation factor of the other deformation mode, and the degree of contribution thereof. In addition, the number and types of generation factors contributing to each deformation mode (for example, three types in the modification mode shown in FIG. 10 and four types in the modification mode shown in FIG. 11) can also be seen at a glance. From the above, it becomes possible to elucidate (at least the tendency of) the deformation mechanism at the time of press forming of the pressed part according to the full size model 10. 10 and 11 are merely illustrated as one of the methods for expressing the distribution of the degree of contribution based on the deformation analysis result, and each of the generation factors A to E and the generation factors F1 to F5 shown in FIG. There is no direct relationship with them.

(S6) Contribution degree reflection step (redesign step)
In this step, the design (redesign) of the pressed part is performed by reflecting the influence (in this case, the degree of contribution) of each generation factor to each deformation mode obtained in the above steps S1 to S5 on the full size model 10 . Specifically, since the contribution degree of the occurrence factor is known for each deformation mode, the correspondence of the normal size model 10 is made so that the factor stress distribution which becomes each occurrence factor becomes as small as possible according to the contribution degree. Change the shape of the part. As a specific example of shape change, addition of a seat surface, addition of a bead, etc. can be mentioned according to the deformation mode. Alternatively, an increase in plate thickness (including superposition of plate-like portions) for the purpose of rigidity improvement can be mentioned.

  In addition, in the case where a plurality of generation factors affect the deformation modes corresponding to each other, it is preferable to implement an individual design change according to the degree of contribution of each generation factor to the deformation mode. This makes it possible to offset the deformation and prevent deformation of the product after press molding (pressed part).

  As described above, in the deformation analysis method of a pressed part according to the present invention, a stress distribution which is actually generated based on an external factor such as a press load in a press-clamped state is replaced by a thermal load in analysis. It applied to the analysis model (size model 10) of When a thermal load is applied to a material to be pressed (press parts in this case) in this type of press forming, that is, a stress distribution generated in the material to be pressed when heat is applied in a clamped state, and the thermal load There is a certain correlation (see FIG. 9). Therefore, based on this correlation, a predetermined thermal load is applied to the full size model 10 as an analysis model of the pressed part so that the desired stress distribution to be applied is generated in the clamped part. As a result, since it is sufficient to specify only the magnitude of heat, the amount of calculation can be significantly reduced compared to the prior art. Therefore, the time required for deformation analysis of the pressed part can be shortened.

  Further, in the deformation factor analysis method of a pressed part according to the present embodiment, a plurality of deformation modes (for example, first to fourth deformation modes M1 to M4 shown in FIG. 4) which can be generated in the pressed part by press forming, and each deformation The factor stress distribution which becomes the generation factor of the mode (for example, the first to sixth generation factors F1 to F5 shown in FIG. 5) is set for each deformation mode, and these factor stress distributions are independently Perform deformation analysis of the full size model 10 when applied, and based on the deformation analysis result, the influence of the generation factor on each deformation mode, specifically, the number of generation factors contributing to each deformation mode, and to each deformation mode We decided to identify the degree of contribution of each occurrence factor. This makes it possible to obtain the following effects.

  That is, conventionally, as shown in, for example, FIG. 12, deformation analysis at the time of press molding is performed from the state where the material to be pressed 1a is disposed between the press dies 2 and 3 (see FIG. 12A). By performing stress analysis on the materials to be pressed 1a to 1c in the order of each step up to the state (refer to FIG. 12 (b)) and the state (refer to FIG. 12 (c)) where the mold is opened The later deformation (see FIG. 12 (d)) was predicted. Therefore, the residual stress distribution produced by clamping the mold and the deformation after mold opening caused by the residual stress distribution (for example, after the above-described press molding) are applied to the material to be pressed 1c after press molding (here, the pressed part) The difference between the shape 1c and the normal shape 1c ', etc.) is only obtained as one result.

  On the other hand, in the deformation factor analysis method according to the present embodiment, the deformation generated in the press part by press molding is a deformation or simple deformation for each part (for example, a plurality of parts shown in FIG. 3 (b) to (d)) In the deformation mode M1, M2 ...). In addition, in order to quantitatively evaluate the evaluation, the factor stress distribution that causes each deformation mode M1, M2 ... as a finished product, not the analysis model before press forming (the analysis model of the material to be pressed 1a) It applied to the full size model 10 (refer FIG. 3 (a)) of the press part of, and decided to perform the deformation analysis of the full size model 10. FIG. Then, based on the deformation analysis result, the number of generation factors contributing to each deformation mode M1, M2... And the contribution degree of each generation factor to each deformation mode M1, M2. As described above, the factor stress distribution that causes each deformation mode is added, and the analysis result of the deformation analysis of the full-size model 10 at that time is performed. It is possible to objectively evaluate the influence (the degree of contribution) on the occurrence factor. Therefore, by performing the above-mentioned deformation analysis on all parts of the full-size model 10 of the pressed part and all kinds of deformation modes, the deformation factors of the entire pressed part are systematically specified, organized and grasped (visualization) ) (See FIGS. 10 and 11). This makes it possible to take appropriate measures for each part type. Further, since the contribution rate of each occurrence factor becomes clear for each deformation mode, it is possible to easily take measures according to each deformation mode. In addition, if it is possible to elucidate deformation factors that cause dimensional accuracy defects at the product drawing stage, redesign the full-size model 10, for example, by incorporating in advance the countermeasure effect of the dimensional accuracy defects and the risk of generating secondary defects. It is possible to improve the degree of completeness of the drawing in a short period of time. Therefore, it becomes possible to design a pressed part at low cost. Of course, if the deformation factor at the time of press molding can be clarified, even if there is a change in part type, it becomes possible to easily develop measures based on the above analysis results to similar parts.

  Moreover, since these factor stress distributions correspond to the deformation mode which is a simple deformation, even if the factor stress distribution is reproduced by the application of a thermal load, high reproduction accuracy can be obtained, which makes it possible to accurately It becomes possible to analyze. Of course, since the pressed parts are formed in a thin shape such as a plate, positive and negative heats 24 and 25 are applied to the front and back to easily reproduce a predetermined stress distribution.

  Further, in the present embodiment, the full size model 10 as an analysis model is formed by a solid model having a plurality of solid elements 21 to 23 in the thickness direction, and a specific solid element (here, a solid on the surface side in the thickness direction) By applying a thermal load to the elements 22 and 23), the factor stress distribution that is the generation factor F1 to F5 of each of the deformation modes M1 to M4 is reproduced. As described above, by creating the full-size model 10 using a solid model having a plurality of solid elements in the thickness direction, it is possible to reproduce an accurate stress distribution in the thickness direction. Of course, by substituting the above-mentioned stress distribution with the thermal load and applying it to the full-sized model 10, it becomes possible to conduct accurate deformation analysis while suppressing the calculation time.

  As mentioned above, although one Embodiment of this invention was described, the deformation | transformation analysis method of the to-be-pressed material which concerns on this invention can also take the structure of that excepting the above in the range which does not deviate from the meaning.

  For example, in the above embodiment, the full-size model 10 as an analysis model is formed of a solid model having three solid elements 21 to 23 in its thickness direction (see FIG. 7), and heat is applied to specific solid elements 22 and 23. Although the case of applying the load has been illustrated, it is of course possible to adopt a solid model having another form. For example, although not shown, the full-size model 10 can be formed as a solid model having two solid elements (three nodes) in the thickness direction, or four or more solid elements in the thickness direction It is also possible to form a solid model. However, if there are too many solid elements in the thickness direction, the advantage of reducing the stress distribution by thermal load (reduction of calculation time) may be lost, so the shape of the material to be analyzed, The number of solid elements in the thickness direction should be set in consideration of the allowable calculation time. Of course, if there is no particular problem in terms of analysis accuracy, a shell model may be adopted instead of the solid model.

  Further, in the above embodiment, although the case where a press-shaped part having a cross-sectional hat shape is used as an analysis target has been described (see FIG. 3 etc.), of course, a press part having a form other than the cross-sectional hat shape Material is also applicable to the present invention. That is, it is possible to apply the deformation analysis method according to the present invention to a material to be pressed having an arbitrary shape as long as press forming is possible.

  Further, in the above embodiment, in the deformation analysis step S4 of the deformation factor analysis method at the time of press molding, with respect to the full size model 10 of the pressed part, the factor stress distribution serving as the generation factor of each deformation mode is heat (heat load) Although the case of giving it as an alternative is illustrated, it is of course possible to apply the present invention to other deformation analysis methods. That is, as long as the stress distribution is generated in the material to be pressed in the clamped state, it is possible to substitute the stress distribution other than the factor stress distribution with the thermal load according to the present invention and give it to the analysis model.

  In addition, regardless of the type of press forming, for example, when performing press forming on a work (pressed material) in a heated state such as warm press forming or hot press forming other than cold press forming, Of course, the invention can be applied.

1a to 1c Pressed materials 2 and 3 Press mold 10 Exact size model 11 of press parts Vertical wall 11c Neutral axis 12 Upper wall 13 First corner 14 Flange 15 Second corner 21 to 23 Solid elements 21a to 23a Nodal point F1-F5, AE Generation factor M1 to M4 Deformation mode S1 Correct model creation step S2 Deformation mode setting step S3 Factor stress setting step S4 Deformation analysis step S41 Correlation acquisition step S42 Thermal load application step S43 Deformation analysis step S5 Contribution Degree identification step (evaluation step)
S6 contribution degree reflection step (redesign step)

Claims (3)

A method of analyzing deformation of a material to be pressed when the material to be pressed is opened from the state of being clamped with a press die,
A correlation acquisition step of acquiring a correlation between a stress distribution generated in the material to be pressed when the thermal load is applied to the material to be pressed and the thermal load;
A thermal load applying step of replacing the stress distribution generated in the pressed material in the clamped state with the thermal load based on the correlation and applying the analysis model of the pressed material;
A deformation analysis method of a material to be pressed, comprising: a deformation analysis step of analyzing a deformation of an analysis model of the material to be pressed when the mold clamping state is changed to the mold opening state.   In the correlation acquisition step, when a thermal load is applied to the basic shape model of the material to be pressed, the stress distribution occurring in the basic shape model is calculated by analysis, and the correlation between the calculated stress distribution and the thermal load is acquired The deformation analysis method of a to-be-pressed material according to claim 1.   The deformation analysis method of a pressed material according to claim 1, wherein the analysis model of the pressed material is formed by a solid model having a plurality of solid elements in a thickness direction.

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