阅读说明：本技术 一种单翼梁裂纹扩展试验装置及试验方法 (Single-spar crack propagation test device and test method ) 是由 李玉莲 林长亮 王虎林 于国庆 张克晓 刘娜 于 2019-10-12 设计创作，主要内容包括：本发明提供一种单翼梁裂纹扩展试验装置,用于进行单翼梁2裂纹扩展试验,所述试验装置包括承力墙1、多个防失稳夹具3、剪力加载装置5、弯矩加载装置6,所述承力墙1用于夹持固定单翼梁2的一端；所述剪力加载装置5位于平行单翼梁2的一侧,用于向单翼梁2施加平行于单翼梁2侧面的腹板剪力；所述弯矩加载装置6包括弯矩加载夹具60和弯矩加载组件61,所述弯矩加载夹具60与单翼梁2相对的两个侧面固定连接；所述弯矩加载组件61与所述弯矩加载夹具60固定连接,所述弯矩加载组件61向所述弯矩加载夹具60施加作用力,用于向所述单翼梁2施加弯矩。(The invention provides a single-wing spar crack propagation test device which is used for carrying out a single-wing spar 2 crack propagation test and comprises a bearing wall 1, a plurality of instability-proof clamps 3, a shear force loading device 5 and a bending moment loading device 6, wherein the bearing wall 1 is used for clamping and fixing one end of the single-wing spar 2; the shear force loading device 5 is positioned on one side of the parallel single-wing spar 2 and is used for applying a web plate shear force parallel to the side face of the single-wing spar 2 to the single-wing spar 2; the bending moment loading device 6 comprises a bending moment loading clamp 60 and a bending moment loading assembly 61, and the bending moment loading clamp 60 is fixedly connected with two opposite side faces of the single-wing beam 2; the bending moment loading assembly 61 is fixedly connected with the bending moment loading clamp 60, and the bending moment loading assembly 61 applies acting force to the bending moment loading clamp 60 and is used for applying bending moment to the single-wing spar 2.)

1. A single wing beam crack propagation test device is used for carrying out a single wing beam (2) crack propagation test and is characterized by comprising a bearing wall (1), a plurality of anti-instability clamps (3), a shear force loading device (5) and a bending moment loading device (6),

the bearing wall (1) is used for clamping and fixing one end of the single wing beam (2);

the anti-instability clamp (3) comprises a clamp connecting piece (30) and an anti-instability clamp (31), the clamp connecting piece (30) and the anti-instability clamp (31) are respectively positioned on two opposite side surfaces of the single wing beam (2), and the upper end and the lower end of the clamp connecting piece (30) and the upper end and the lower end of the anti-instability clamp (31) are correspondingly and fixedly connected; the clamp connecting piece (30) is matched with the anti-instability clamp (31) to clamp the single wing beam (2);

the shear force loading device (5) is positioned on one side of the parallel single-wing beam (2) and is used for applying a web plate shear force parallel to the side face of the single-wing beam (2) to the single-wing beam (2);

the bending moment loading device (6) comprises a bending moment loading clamp (60) and a bending moment loading assembly (61), the bending moment loading clamp (60) comprises a first bending moment loading clamp (601) and a second bending moment loading clamp (602), the first bending moment loading clamp (601) and the second bending moment loading clamp (602) are respectively located on two opposite side faces of the single wing beam (2) and located at one end, far away from the bearing wall (1), of the single wing beam (2), and the first bending moment loading clamp (601) and the second bending moment loading clamp (602) are matched to clamp the single wing beam (2) and are fixedly connected with the single wing beam (2); the bending moment loading assembly (61) is fixedly connected with the bending moment loading clamp (60), and the bending moment loading assembly (61) applies acting force to the bending moment loading clamp (60) and is used for applying bending moment to the single wing beam (2).

2. A test device according to claim 1, wherein the shear loading device (5) is a first ram having a first load cell (50) disposed at an end of the first ram adjacent the spar (2), the first load cell (50) being located between the first ram and the spar (2) for measuring the web shear force applied by the first ram.

3. The test rig according to claim 1, wherein the bending moment loading assembly (61) comprises a first bending moment loading plate (610), a second bending moment loading plate (612) and two second rams (611), the first bending moment loading plate (610) being fixedly connected with the first bending moment loading clamp (601), the second bending moment loading plate (612) being fixedly connected with the first bending moment loading clamp (601),

the first bending moment loading plate (610) and the second bending moment loading plate (612) respectively comprise two loading rods extending in parallel, and the two second actuating cylinders (611) are respectively and correspondingly fixedly connected with the two loading rods of the first bending moment loading plate (610) and the second bending moment loading plate (612) and used for applying acting force to the loading rods.

4. A test device according to claim 3, wherein the second actuator cylinder (611) is provided with a second load cell (51) at an end thereof adjacent the load bar, the second load cell (51) being located between the second actuator cylinder (611) and the load bar for measuring the force applied to the load bar by the second actuator cylinder (611).

5. Test rig according to claim 1, characterized in that the test rig comprises at least 3 anti-buckling clamps (3), which 3 anti-buckling clamps (3) are each located at a position where a single spar is supported by a rib in the aircraft structure for simulating the bracing of the rib structure, the skin structure, to the single spar structure in a wing box.

6. Testing device according to claim 1, characterized in that the single spar (2) comprises a tab (20), one end of the shear loading device (5) being fixedly connected with the tab (20).

7. A single spar crack propagation test method using a test apparatus according to any of claims 1 to 6, the method comprising,

one end of the single wing beam (2) is clamped and fixed by a bearing wall (1); the anti-destabilization clamp (3) clamps two opposite side surfaces of the single wing beam (2); the bending moment loading clamp (60) clamps and fixes the two opposite side surfaces at the other end of the single wing beam (2) and is fixedly connected with the single wing beam (2), and the bending moment loading assembly (61) is fixedly connected with the bending moment loading clamp (60);

the two second actuating cylinders (611) respectively apply acting forces in different directions or different magnitudes to the two loading rods extending in parallel of the first bending moment loading plate (610) and the second bending moment loading plate (612), so that bending moment loading on the single-wing beam (2) is realized, and the two second actuating cylinders are used for simulating expansion crack propagation;

the directions of the forces exerted by the two second rams (611) are parallel.

8. The crack propagation test method of claim 7, further comprising,

applying a web plate shearing force parallel to the side surface of the single wing beam (2) to the single wing beam (2) by using a shearing force loading device (5); meanwhile, the two second actuating cylinders (611) respectively apply acting forces in different directions or different magnitudes to the two loading rods extending in parallel of the first bending moment loading plate (610) and the second bending moment loading plate (612), and meanwhile, the shear loading and bending moment loading of the single-wing spar (2) are achieved, and the composite crack propagation simulation device is used for simulating composite crack propagation.

9. The crack propagation test method of claim 8, further comprising, prior to performing the crack propagation test, performing a pre-crack of an initial crack of the single spar structure, the pre-crack being performed at a crack tip of a lower cap of the single spar.

Technical Field

The invention belongs to the technical field of spar tests, and relates to a crack propagation test method and a test device.

Background

The concept of damage tolerance is currently widely used in aircraft structural design, where the damage tolerance design recognizes the presence of undetected initial defects in the structure, requiring that the propagation of defects (cracks) be controlled within a certain range under the repeated action of the service loads. In the compliance methods of the airworthiness provisions of the CCAR23.573 and CCAR23.574, it is specifically stated that tests are selected or that a test-based supported analysis is used to indicate that the structure meets the airworthiness provisions. In aircraft structural damage tolerance design, damage to the wing spar can cause catastrophic damage, and crack propagation control of the wing spar is particularly important. The spar crack propagation test is also a damage tolerance test that must be performed by the aircraft to meet airworthiness requirements.

In practical engineering application, when a traditional test method is adopted for carrying out a spar crack propagation test, in order to truly simulate the actual stress boundary condition of a spar, the whole test is carried out by mostly adopting a wing box structure with the spacing length of 3 ribs. The test method for carrying out the crack propagation test by adopting the wing box structure has the advantages of high manufacturing cost of a test piece, large and heavy structure and low crack propagation test efficiency. In the crack propagation process of the wing beam, the whole wing box structure is complex, the load of the wing beam can be transferred along with the difference of the length of the crack, the crack propagation test scale performed by adopting the whole wing box structure is large, and the test cost is high. If the single-spar structure is adopted for testing, the boundary requirements of the test load and the constraint can be met, and the cost of the test can be greatly reduced.

Disclosure of Invention

The invention aims to design a single-wing spar crack propagation test device and a test method.

The invention provides a crack propagation test device for a single wing spar, which is simple and convenient, can effectively improve the efficiency of the crack propagation test of the single wing spar, can independently perform the crack propagation test on the wing spar, simulate the boundary support condition of a wing box on the single wing spar, and simulate the transfer of the whole wing box structure load of a wing web plate in the crack propagation process, and has simple structure form and low cost.

On one hand, the invention provides a single wing spar crack propagation test device which is used for carrying out a single wing spar 2 crack propagation test and comprises a bearing wall 1, a plurality of anti-instability clamps 3, a shear force loading device 5 and a bending moment loading device 6,

the bearing wall 1 is used for clamping and fixing one end of the single wing beam 2;

the anti-instability clamp 3 comprises a clamp connecting piece 30 and an anti-instability clamp 31, the clamp connecting piece 30 and the anti-instability clamp 31 are respectively positioned on two opposite side surfaces of the single wing beam 2, and the upper end and the lower end of the clamp connecting piece 30 and the upper end and the lower end of the anti-instability clamp 31 are correspondingly fixedly connected and used for clamping the single wing beam 2;

the shear force loading device 5 is positioned on one side of the parallel single-wing spar 2 and is used for applying a web plate shear force parallel to the side face of the single-wing spar 2 to the single-wing spar 2;

the bending moment loading device 6 comprises a bending moment loading clamp 60 and a bending moment loading assembly 61, the bending moment loading clamp 60 comprises a first bending moment loading clamp 601 and a second bending moment loading clamp 602, the first bending moment loading clamp 601 and the second bending moment loading clamp 602 are respectively positioned on two opposite side surfaces of the single-wing spar 2 and positioned at one end of the single-wing spar 2 far away from the bearing wall 1, and the first bending moment loading clamp 601 and the second bending moment loading clamp 602 clamp the single-wing spar 2 and are fixedly connected with the single-wing spar 2; the bending moment loading assembly 61 is fixedly connected with the bending moment loading clamp 60, and the bending moment loading assembly 61 applies acting force to the bending moment loading clamp 60 and is used for applying bending moment to the single-wing spar 2.

Further, the shear force loading device 5 is a first actuator cylinder, one end of the first actuator cylinder, which is close to the single-wing spar 2, is provided with a first load cell 50, and the first load cell 50 is located between the first actuator cylinder and the single-wing spar 2 and is used for measuring the web shear force applied by the first actuator cylinder.

Further, the bending moment loading assembly 61 includes a first bending moment loading plate 610, a second bending moment loading plate 612 and two second actuators 611, the first bending moment loading plate 610 is fixedly connected to the first bending moment loading fixture 601, the second bending moment loading plate 612 is fixedly connected to the first bending moment loading fixture 601,

the first bending moment loading plate 610 and the second bending moment loading plate 612 respectively include two loading rods extending in parallel, and the two second actuators 611 are respectively and fixedly connected to the two loading rods of the first bending moment loading plate 610 and the second bending moment loading plate 612, and are configured to apply an acting force to the loading rods.

Further, a second load cell 51 is disposed at one end of the two second actuators 611 close to the loading rod, and the second load cell 51 is located between the second actuators and the loading rod and is used for measuring the acting force applied to the loading rod by the second actuators.

Further, the test apparatus comprises at least 3 anti-buckling clamps 3, each located at a position where a single spar is supported by a rib in the aircraft structure.

Further, the single spar 2 comprises a lug 20, and one end of the shear loading device 5 is fixedly connected with the lug 20.

In another aspect, there is provided a single spar crack propagation test method, using a test apparatus as described above, characterised in that the method comprises,

one end of a single wing beam 2 is clamped and fixed by a bearing wall 1; the anti-instability clamp 3 clamps two opposite side surfaces of the single wing beam 2; the bending moment loading clamp 60 clamps and fixes the two opposite side surfaces at the other end of the single-wing beam 2 and is fixedly connected with the single-wing beam 2, and the bending moment loading assembly 61 is fixedly connected with the bending moment loading clamp 60;

the two second actuating cylinders 611 respectively apply acting forces in different directions or different magnitudes to one ends of two loading rods extending in parallel of the first bending moment loading plate 610 and the second bending moment loading plate 612, so that bending moment loading on the single-wing spar 2 is realized, and the two second actuating cylinders are used for simulating expansion crack propagation;

the directions of the forces applied by the two second rams 611 are parallel.

Further, the method may further comprise,

applying a web plate shearing force parallel to the side surface of the single wing beam 2 to the single wing beam 2 by using a shearing force loading device 5; meanwhile, the two second actuators 611 respectively apply acting forces in different directions or different magnitudes to one ends of two loading rods extending in parallel of the first bending moment loading plate 610 and the second bending moment loading plate 612, and simultaneously realize shear loading and bending moment loading on the single-wing spar 2, so as to simulate composite crack propagation.

Further, the method includes, prior to performing the crack propagation test, performing a pre-crack of an initial crack of the single spar structure, the pre-crack being performed at a crack tip of the single spar lower rail.

The invention has the technical effects that:

the single wing spar crack propagation test device is simple in structure, can effectively improve the efficiency of a wing spar crack propagation test, can independently perform the crack propagation test on a wing spar, simulate the boundary support condition of a wing box on the single wing spar, and simulate the transfer of the structural load of the whole wing box of a wing web in the crack propagation process, and the test assembly is simple in structural form and low in cost.

The test device combines two groups of loading systems, and realizes I-type (open type) crack propagation and II-type (slip type) crack propagation simulating crack propagation and a single-wing beam composite crack propagation test with two crack configurations existing simultaneously by adjusting the proportion of the shear loading systems. The single-wing spar crack propagation test method is designed based on a simple and practical principle, the test piece is easy to install and disassemble, the boundary constraint and loading condition of the single-wing spar are easy to simulate, the scale of the test piece is reduced, and the cost of a test tool and a test is controlled.

Drawings

FIG. 1 is a schematic diagram of the test apparatus of the present invention;

FIG. 2 is a disassembled schematic view of the test apparatus of the present invention.

Detailed Description