CN111256925A - Large-deflection small-strain structure follow-up normal loading implementation method - Google Patents
Large-deflection small-strain structure follow-up normal loading implementation method Download PDFInfo
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- CN111256925A CN111256925A CN202010177351.5A CN202010177351A CN111256925A CN 111256925 A CN111256925 A CN 111256925A CN 202010177351 A CN202010177351 A CN 202010177351A CN 111256925 A CN111256925 A CN 111256925A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M5/00—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings
- G01M5/0016—Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings of aircraft wings or blades
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- G—PHYSICS
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- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
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Abstract
A servo normal loading implementation method for a large-deflection small-strain structure is characterized in that after the large-deflection small-strain structure is fixed and is subjected to weight deduction treatment, an actuating cylinder is installed and fixed and is connected and matched with a structure loading point, and finally, servo loading with a determined step length is carried out to obtain a more accurate detection result.
Description
Technical Field
The invention relates to a technology in the field of mechanical structures, in particular to a method for realizing follow-up normal loading for simulating a large-deflection small-strain structure, such as follow-up aerodynamic loading on a full-size wing.
Background
The existing structural strength verification method is mainly used as follows: and applying a certain proportion of design load to the structural member to observe whether the designed structural member can meet the design requirement, and mainly observing whether the detected structural member has phenomena of buckling, damage, instability and the like in the design load range. The conventional load applying method can only change the load, and the direction of the load is difficult to adjust at any time along with the load deformation of the structure. For small deflection type structures that generally deform less than 1% of their length, the loads and directions applied during the test can effectively and accurately simulate normal loads, but for large deflection type structures, especially large deflection small strain type structures such as aircraft wings, the results obtained would be very inaccurate if direct normal loading methods were also employed. Because the airplane wing generates larger deformation (the deformation amount of the wing tip can even reach about 30% of the length of the wing) along with the increase of the load, the traditional load application method is always perpendicular to the original wing surface and is not changed, and the aerodynamic load born by the wing in the deformation process cannot be accurately simulated (the aerodynamic load is always perpendicular to the wing surface).
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a method for realizing the follow-up normal loading of a large-deflection small-strain structure.
The invention is realized by the following technical scheme:
after the large-deflection small-strain structure is fixed and the weight is deducted, the actuating cylinder is installed and fixed and is connected and matched with the structure loading points, and finally the follow-up loading with the determined step length is carried out.
Technical effects
The invention integrally solves the problem that the traditional normal loading method can not adjust the load direction in time along with the deformation of the structure in the load application process. Compared with the prior art, the invention can adjust the loading direction along with the structure deformation so as to realize the follow-up normal loading, greatly improve the accuracy of the detection result, and particularly improve the accuracy and the reliability of the result by adopting the follow-up loading design of the invention for the large-deflection small-strain structure. In addition, the follow-up loading design provided by the invention is simple and easy to implement, and has strong engineering practicability.
Drawings
FIG. 1 is a loading axial view of a loading point card and structure of the present invention;
FIG. 2 is a loading elevation view of the load point card and structure of the present invention;
FIG. 3 is a loading side view of the load point card and structure of the present invention;
FIG. 4 is a top view of the load point card and structure of the present invention;
FIG. 5 is a schematic view of the servo loading step of the present invention;
in the figure: 1 is a clamping plate, 2 is a large-deflection small-strain structure, 3 is a fixed platform, 4 is a protective rubber pad, 5 is a main body part of the actuating cylinder, 6 is a base of the actuating cylinder, and 7 is a sliding chute.
Detailed Description
As shown in fig. 1 to 4, the present embodiment relates to a follow-up normal loading device for a large-deflection small-strain structure, which implements the above method, and includes: base with spout 7 and set up in fixed platform 3 and the pressurized cylinder 5 at base both ends, wherein: one end of the large-deflection small-strain structure 2 is vertically connected with the fixed platform 3, and the other end of the large-deflection small-strain structure is arranged at the top of the actuating cylinder 5 through the clamping plate 1.
The bottom of the actuating cylinder 5 is arranged in the sliding groove 7 in a sliding manner through the actuating cylinder base 6.
And a protective rubber pad 4 is arranged between the clamping plate 1 and the large-deflection small-strain structure 2.
As shown in fig. 2, the method for implementing the follow-up normal loading of the large-deflection small-strain structure by using the device comprises the following steps:
step 1) fixing a large-deflection small-strain structure: one end of the large-deflection small-strain structure 2 to be loaded is fixed through the fixed platform 3 to form a cantilever-like beam structure, so that load is applied to the large-deflection small-strain structure.
The large-deflection small-strain structure 2 is a constant section or variable section structure with a solid or hollow structure, and the cross section size of the structure is far smaller than the whole length, preferably smaller than 10%.
Step 2) weight deduction treatment: firstly, combining and calculating the gravity center of the large-deflection small-strain structure 2 and the gravity center of the fixed platform 3 to obtain the gravity center of the weight, and applying a load with the same reverse direction and the same size according to the gravity center position of the weight and the loading direction of a loading point, thereby realizing weight deduction.
The number of the loading points is calculated according to the length of the large-deflection small-strain structure 2, and the interval between the loading points is preferably about 0.5-1 m.
The position of the loading point is preferably as follows: the fixed platform 3 and the fixed point of the large-deflection small-strain structure 2 are uniformly distributed towards the other end.
Step 3) mounting and fixing the actuating cylinder and connecting the actuating cylinder with a structural loading point: the main body part 5 of the actuating cylinder for applying load to the structure is rotatably connected with the base 6 through a ball cage to realize all-directional rotation, the base is connected and fixedly arranged on a sliding groove 7 of a fixed platform through a bolt, and the actuating cylinder is connected with the clamping plate 1 of the structural profile matched with the corresponding loading point position.
And a protective rubber pad 4 is arranged between the clamping plate and the actuating cylinder.
Step 4), follow-up loading design: for a large-deflection small-strain structure, normal follow-up loading is realized by using a slide rail to move an actuator cylinder and predicting a next-stage offset angle by combining with an Excel smooth curve or a sample line function in Catia software, and the method specifically comprises the following steps:
4.1) 0% -40% load stage, i.e. 0% load point A1To 40% load point A2: line OA from the fixed point to the ram vertex as shown in FIG. 21Curve OA from fixed point to 40% load point2L is shown as the distance from the fixed point O at one end of the structure to the fixed platform. Firstly, in an initial state of 0%, after the weight is deducted, the large-deflection small-strain structure is in a horizontal state, and at the moment, the fixed placing position of the actuating cylinder is shown as A in figure 21B1Shown therein, the arrangement position A of the actuating cylinder1B1Perpendicular to the initial position of the structure. Control actuator to apply load to 40% design load (fixed point to 40% load point curve OA)2) The position of the base is unchanged, and the direction of the main body part of the actuating cylinder changes along with the deformation of the structure.
4.2) 40% -60% loading stage, i.e. 40% load point A2To 60% load point A3: curve OA from fixed point to 40% load point of fig. 22Curve OA from fixed point to 60% load point3The initial position of the ram is shown from a1B1Moving to the projection connecting line A of the 40% load point and the 80% load point2B4Position, wherein 40% load point and 80% load point projection connecting line A2B4Line OA connecting fixed point of vertical curve to 40% load point2At 40% load point A2. To obtain a straight line A2B4Firstly, the whole deformation of the large-deflection small-strain structure can be fitted according to the position of each loading point when the load is designed by 40 percent (Excel smooth curve or the function of a sample line in Catia software can be quickly realized), and then A is passed2Making a point as a perpendicular line, and fixing the platform at a point B4And find point B4Position in which A2B4At an angle theta to the vertical1). The actuating cylinder moves the base through the sliding groove to move the base from the position B1Move to B4. Control actuator to apply load to 60% design load (curve OA)3) The position of the base is unchanged, and the direction of the main body part of the actuating cylinder changes along with the deformation of the structure.
4.3) 60% -100% Loading stage, i.e. 60% load Point A3To 100% load point A4: curve OA from fixed point to 60% load point of fig. 23Curve OA from fixed point to 100% load point4The initial position of the ram is shown as projected from 40% load point to 80% load point on line a2B4Moving to 60% load point and auxiliary point connecting line A3B5Position in which A3B5Vertical curve OA3At point A3. To obtain a straight line A3B5Firstly, the whole deformation of the large-deflection small-strain structure can be fitted according to the position of each loading point during 60% of design load, and then A is passed3Making a point into a perpendicular line, and fixing the platform at an auxiliary point B5I.e. finding the auxiliary point B5Position in which A3B5At an angle theta to the vertical2). The actuating cylinder moves the base through the sliding groove to move the base from the position B3Move to B5. Control actuator to apply load to 100% design load (curve OA)4) The position of the base is unchanged, and the direction of the main body part of the actuating cylinder changes along with the deformation of the structure.
And 4) in the step 4), the load of the actuating cylinder takes 5% as one stage, the load is gradually loaded to 60% of limit load, strain and displacement are collected at each stage, the load is manually kept for 60s, and the tooling, the loading equipment and the collecting equipment are checked and recorded.
Preferably, in the step 4.3), the load of the actuator cylinder is gradually loaded to 90% of the limit load by taking 2% as one stage in the range of 60% -90%, the load of the actuator cylinder is gradually loaded to 100% by taking 1% as one stage in the range of 90% -100%, the load is kept for 30 seconds, and each stage collects strain and displacement. And in the test process, attention is paid to checking whether the test piece and the clamp are normal or not, and monitoring test data such as displacement, strain and the like.
Preferably, the step of adjusting the ram in step 4) may also be divided by 0% -20%, 20% -40%, 40% -60%, 60% -80%, 80% -100%, and even more steps may be divided to obtain more accurate simulated pneumatic loading. The more times the ram base position is adjusted with load, the more accurate the load is applied, but also at the same time greater time and computational costs are incurred.
Through specific actual detection, under the room temperature setting, starting according to the actual structure size according to the steps, the detection data which can be obtained are as follows: displacement of structural loading point, loading force, and sliding groove position point.
Compared with the prior art, the larger the deformation generated when a large-deflection small-strain part is loaded, the higher the accuracy of the normal follow-up loading method provided by the invention is.
The foregoing embodiments may be modified in many different ways by those skilled in the art without departing from the spirit and scope of the invention, which is defined by the appended claims and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims (6)
1. A method for realizing follow-up normal loading of a large-deflection small-strain structure is characterized in that after the large-deflection small-strain structure is fixed and is subjected to buckling treatment, an actuating cylinder is installed and fixed and is connected and matched with a structure loading point, and finally follow-up loading with a determined step length is performed, and the method comprises the following specific steps of:
① fixing one end of the large-deflection small-strain structure to be loaded through the fixed platform and the three-dimensional truss and forming a cantilever-like beam structure, thereby applying load to the large-deflection small-strain structure;
② combining and calculating the gravity center of the large-deflection small-strain structure and the gravity center of the fixed platform to obtain the gravity center of the weight, and applying a load with the same reverse direction according to the gravity center position of the weight and the loading direction of the loading point to realize weight deduction;
③ the main body part of the actuator cylinder for applying load to the structure is rotationally connected with the base through a ball cage to realize the rotation in all directions, the base is connected with the sliding chute of the fixed platform through a bolt and is fixedly arranged, and the actuator cylinder is connected with the clamping plate matched with the structural profile of the corresponding loading point position;
④ for large deflection small strain structure, the normal follow-up loading is realized by using slide rail to move the actuator cylinder and combining with smooth curve or spline to predict the next stage offset angle.
2. The method for realizing the follow-up normal loading of the large-deflection small-strain structure as claimed in claim 1, wherein the large-deflection small-strain structure is a constant section or variable section structure of a solid or hollow structure, and the size of the cross section of the large-deflection small-strain structure is less than 10% of the whole length.
3. The method for realizing the follow-up normal loading of the large-deflection small-strain structure according to claim 1, wherein the number of the loading points is calculated according to the length of the large-deflection small-strain structure; the interval between the loading points is 0.5-1 m; the positions of the loading points are: the fixed platform and the fixed points of the large-deflection small-strain structure are uniformly distributed towards the other end.
4. The method for realizing the follow-up normal loading of the large-deflection small-strain structure as claimed in claim 1, wherein a protective rubber pad is arranged between the clamping plate and the actuating cylinder.
5. The method as claimed in claim 1, wherein in step ④, the actuator cylinder load is loaded to 60% of the limit load step by step with 5% as one step, each step collects strain and displacement, manually holds the load for 60s, and checks and records the tool and loading equipment and collecting equipment.
6. A follow-up normal loading device for a large-deflection small-strain structure for realizing the method of any one of claims 1 to 5, which is characterized by comprising the following steps: base with spout and set up in fixed platform and the pressurized cylinder at base both ends, wherein: one end of the large-deflection small-strain structure is vertically connected with the fixed platform, and the other end of the large-deflection small-strain structure is arranged at the top of the actuating cylinder through the clamping plate;
the bottom of the actuating cylinder is arranged in the sliding groove in a sliding manner through the actuating cylinder base;
and a protective rubber pad is arranged between the clamping plate and the large-deflection small-strain structure.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112730066A (en) * | 2020-12-28 | 2021-04-30 | 中国航发沈阳发动机研究所 | Load loading angle adjusting device and method for structural member bearing test |
| CN113218650A (en) * | 2021-06-04 | 2021-08-06 | 中国飞机强度研究所 | Landing gear strength test vertical load loading device |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1519346A1 (en) * | 1987-07-20 | 1995-07-20 | В.В. Дровянкин | Method of testing airframe for fatigue |
| CN105758629A (en) * | 2014-12-19 | 2016-07-13 | 成都飞机设计研究所 | Servo loading method in aircraft strength test |
| CN106596029A (en) * | 2016-11-30 | 2017-04-26 | 中国航空工业集团公司沈阳飞机设计研究所 | Wing pneumatic load follow-up loading device |
-
2020
- 2020-03-13 CN CN202010177351.5A patent/CN111256925A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU1519346A1 (en) * | 1987-07-20 | 1995-07-20 | В.В. Дровянкин | Method of testing airframe for fatigue |
| CN105758629A (en) * | 2014-12-19 | 2016-07-13 | 成都飞机设计研究所 | Servo loading method in aircraft strength test |
| CN106596029A (en) * | 2016-11-30 | 2017-04-26 | 中国航空工业集团公司沈阳飞机设计研究所 | Wing pneumatic load follow-up loading device |
Non-Patent Citations (2)
| Title |
|---|
| 刘文珽: "《结构可靠性设计手册》", 29 February 2008, 国防工业出版社 * |
| 覃湘桂 等: "大变形条件下机翼法向载荷的随动加载技术", 《南京航空航天大学学报》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112730066A (en) * | 2020-12-28 | 2021-04-30 | 中国航发沈阳发动机研究所 | Load loading angle adjusting device and method for structural member bearing test |
| CN112730066B (en) * | 2020-12-28 | 2024-01-02 | 中国航发沈阳发动机研究所 | Device and method for adjusting loading angle of structural member bearing test load |
| CN113218650A (en) * | 2021-06-04 | 2021-08-06 | 中国飞机强度研究所 | Landing gear strength test vertical load loading device |
| CN113218650B (en) * | 2021-06-04 | 2023-12-22 | 中国飞机强度研究所 | Vertical load loading device for landing gear strength test |
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