Flexible telescopic rod buckling performance test system and test method

Abstract

The invention provides a flexible telescopic rod buckling performance test system and method, and the system is characterized in that guide rods are fixedly installed between a loading device and a supporting platform, the two ends of a sample are respectively provided with a group of rod piece fixing joints, and the loading device and the supporting platform are respectively and fixedly provided with a connecting block; the fixed joint is hinged with a connecting block on the loading device through a pin, and the fixed joint is hinged with a connecting block on the supporting platform through a pin; a limiting block is installed between the connecting block on the loading device and the rod piece fixing connector, so that the connecting block on the loading device and the rod piece fixing connector are relatively fixed, and the limiting block is installed or not installed between the connecting block on the supporting platform and the rod piece fixing connector; and the vision measurement equipment is arranged beside the loading device and is used for recording the deformation of the rod piece. The load can be directionally, uniformly and controllably applied, so that the stable and reliable testing process of the flexible telescopic rod is ensured, and the buckling load and the buckling deformation characteristic of the thin-wall flexible rod piece with the large slenderness ratio are obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite material testing, in particular to a flexible telescopic rod buckling performance testing system and testing method. BACKGROUND

[0002] The flexible carbon fiber telescopic rod can be used as a driving and supporting structure of a spacecraft telescopic mechanism, has multiple outstanding advantages such as light mass, small folding volume, small thermal expansion coefficient, integrated structure mechanism, passive self-unfolding and high reliability, and is a new type of unfolding structure mechanism of a spacecraft high-power large-stow-ratio flexible wing and the like.

[0003] However, due to the characteristics such as low self-rigidity, poor stability and large size, the flexible carbon fiber telescopic rod is difficult to test, and there is no mature method for related performance evaluation. SUMMARY

[0004] In view of the defects in the prior art, the present application aims to provide a flexible telescopic rod buckling performance testing system and testing method.

[0005] According to the flexible telescopic rod buckling performance testing system provided by the present application, the loading device, the guide rod, the sample, the rod piece fixing joint, the limiting block, the connecting block, the support platform and the visual measurement equipment are included. The guide rod is fixedly installed between the loading device and the support platform, and a group of rod piece fixing joints are respectively arranged at both ends of the sample. The rod piece fixing joint at one end of the sample is hingedly connected to the connecting block on the loading device through a pin, and the rod piece fixing joint at the other end of the sample is hingedly connected to the connecting block on the support platform through a pin. The connecting block on the loading device and the rod piece fixing joint are fixed relative to each other by installing a limiting block therebetween, and the connecting block on the support platform and the rod piece fixing joint are fixed relative to each other by installing a limiting block therebetween or without installing a limiting block therebetween. The visual measurement equipment is arranged beside the loading device and is used for recording the deformation of the rod piece.

[0006] Preferably, if the sample is a cantilever beam structure, a limiting block is installed between the connecting block on the support platform and the rod piece fixing joint, so that the connecting block on the support platform and the rod piece fixing joint are fixed relative to each other. If the sample is a truss structure, no limiting block is installed between the connecting block on the support platform and the rod piece fixing joint, so that the connecting block on the support platform and the rod piece fixing joint are hingedly constrained.

[0007] Preferably, the shape and fixing form of the rod fixing joint and the connecting interface of the sample are matched according to the actual shape and interface position of the sample.

[0008] Preferably, the loading device comprises a hydraulic loading system and a force displacement sensor, and the sample is pressurized and the force and displacement values in the loading process are measured and recorded.

[0009] Preferably, the guide rod is provided with one on each side of the sample, so as to ensure that the loading direction is vertical.

[0010] Preferably, the visual measurement device comprises two measurement cameras arranged orthogonally.

[0011] Preferably, the connecting block is provided with a hinged seat, the rod fixing joint is provided with a hinge joint on the side away from the sample, and the hinge joint is hinged with the hinged seat through a pin.

[0012] Preferably, the hinged shafts of the connecting block and the rod fixing joint are parallel to the radial direction of the sample.

[0013] Preferably, the shape of the limiting block allows the limiting block to be clamped with the hinged seat on the connecting block, and the limiting block clamped on the hinged seat on the connecting block abuts against the rod fixing joint.

[0014] According to the present application, a flexible telescopic rod buckling performance test method is provided, and the test method comprises the following steps: S1, installing a loading device, and associating the loading device with a support platform through a guide rod; S2, installing the connecting block on the loading device and the support platform by means of fasteners; S3, connecting the rod fixing joint with the end of the sample by means of gluing or screwing; S4, connecting the rod fixing joint with the corresponding connecting block by means of a pin; S5, if the loading boundary condition is a hinged constraint, the limiting block is not installed, and if the loading boundary condition is a fixed constraint, the limiting block is installed; S6, calibrating the visual measurement device; S7, starting the visual measurement device and recording image data; S8, starting the loading device, applying a compression load to the sample, and recording the loading load and displacement values through the sensor; S9, loading to the sample until buckling occurs, obtaining the buckling load through the loading device, and obtaining the buckling deformation characteristics through the visual measurement device; S10, turning off the loading device and the visual measurement device.

[0015] Compared with the prior art, the present application has the following beneficial effects: 1. The application can realize directional, uniform and controllable load application through the guide rod and the loading device, thereby ensuring the stability and reliability of the flexible telescopic rod test process, and through the limiting block, the multi-working condition measurement of the test system is realized, and finally the instability deformation characteristics are recorded by the visual measurement system, so that the buckling load and instability deformation characteristics of the large slenderness ratio thin-walled flexible rod are obtained. BRIEF DESCRIPTION OF DRAWINGS

[0016] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, read in conjunction with the accompanying drawings: Fig. 1 The structure diagram of the flexible telescopic rod buckling performance test system is mainly embodied in the application; Fig. 2 The local enlarged view of the area A as a fixed constraint is mainly embodied in the application; Fig. 3 The local enlarged view of the area A as a hinged constraint is mainly embodied in the application.

[0017] As shown in the figure: 1, loading device; 2, guide rod; 3, sample; 4, rod fixing joint; 5, limiting block; 6, connecting block; 7, support platform; 8, visual measurement equipment. DETAILED DESCRIPTION

[0018] The application will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the application, but do not limit the application in any form. It should be pointed out that for those skilled in the art, without departing from the concept of the application, a number of changes and improvements can be made. These all belong to the protection scope of the application.

[0019] As Figs. 1 to 3As shown, the flexible telescopic rod buckling performance test system provided by the application comprises a loading device 1, a guide rod 2, a test sample 3, a rod fixing joint 4, a limiting block 5, a connecting block 6, a support platform 7 and a visual measurement device 8. The guide rod 2 is fixedly installed between the loading device 1 and the support platform 7, and a group of rod fixing joints 4 is arranged at each end of the test sample 3. The connecting block 6 is fixedly installed on the side wall of the loading device 1 facing the support platform 7 and the side wall of the support platform 7 facing the loading device 1. The rod fixing joint 4 at one end of the test sample 3 is hingedly connected to the connecting block 6 on the loading device 1 through a pin, and the rod fixing joint 4 at the other end of the test sample 3 is hingedly connected to the connecting block 6 on the support platform 7 through a pin. The limiting block 5 is installed between the connecting block 6 on the loading device 1 and the rod fixing joint 4, so that the connecting block 6 on the loading device 1 and the rod fixing joint 4 are relatively fixed, and the limiting block 5 is installed or not installed between the connecting block 6 on the support platform 7 and the rod fixing joint 4. The visual measurement device 8 is arranged beside the loading device 1 and is used for recording the deformation of the rod.

[0020] The technical scheme of the application can realize stable testing of the buckling performance of a large slenderness ratio thin-walled flexible rod by adopting loading direction guidance, boundary condition constraint and stable loading control, and the visual measurement device 8 can be used to record the deformation process of the rod, so that the buckling load and instability deformation characteristics of the large slenderness ratio thin-walled flexible rod can be finally obtained.

[0021] Specifically, if the test sample 3 is a cantilever beam structure and the loading boundary condition is fixed constraint, the limiting block 5 is installed between the connecting block 6 on the support platform 7 and the rod fixing joint 4, so that the connecting block 6 on the support platform 7 and the rod fixing joint 4 are relatively fixed. If the test sample 3 is a rod system structure and the loading boundary condition is hinged constraint, the limiting block 5 is not installed between the connecting block 6 on the support platform 7 and the rod fixing joint 4, so that the connecting block 6 on the support platform 7 and the rod fixing joint 4 are hingedly constrained. It should be noted that the connecting interface shape and fixing form of the rod fixing joint 4 and the test sample 3 are matched according to the actual shape and interface position of the test sample 3.

[0022] More specifically, the loading device 1 comprises a hydraulic loading system and a force displacement sensor, which are used to pressurize the test sample 3 and measure and record the force and displacement measurement values in the loading process. It should be noted that the hydraulic loading system and the force displacement sensor in the prior art are used in the application.

[0023] In a preferred embodiment, one guide rod 2 is arranged on each side of the test sample 3 to ensure that the loading direction is vertical. The visual measurement device 8 comprises two measurement cameras which are arranged orthogonally.

[0024] In one feasible embodiment, a hinge seat is provided on the connecting block 6, and a hinge joint is provided on the side of the rod fixing joint 4 opposite to the sample 3. The hinge joint is hinged to the hinge seat by a pin. The hinge axis of the connecting block 6 and the rod fixing joint 4 is parallel to the radial direction of the sample 3. The shape of the limiting block 5 allows the limiting block 5 to engage with the hinge seat on the connecting block 6, and the limiting block 5 on the hinge seat engaged with the connecting block 6 abuts against the rod fixing joint 4. Preferably, the hinge seat of this application includes two protruding edges arranged at relative intervals. The limiting block 5 is provided with an opening of the same shape as the protruding edges to ensure that the limiting block 5 can engage with the protruding edges of the hinge seat. When the limiting block 5 is engaged with the protruding edges of the hinge seat, one side of the limiting block 5 abuts against the connecting block 6, and the other side of the limiting block 5 abuts against the rod fixing joint 4. Further, the end of the protruding edge of the limiting block 5 away from the connecting block 6 is set as an arc shape to facilitate hinge engagement.

[0025] The technical solution of this application achieves reliable control of the loading load through loading direction guidance, boundary condition constraints and stable loading control, ensuring the slow and uniform application of the buckling test load of the flexible telescopic rod. The boundary fixed support or hinged support constraints can be adjusted by assembling and disassembling components to realize buckling tests under multiple working conditions. The buckling load test results are obtained through sensors, and the instability deformation characteristics are recorded through a visual measurement system.

[0026] The guide rod 2 and the loading device 1 enable the load to be applied in a directional, uniform and controllable manner, thereby ensuring the stability and reliability of the flexible telescopic rod test process. At the same time, the limiting block 5 enables multi-condition measurement of the test system, and the final instability deformation characteristics are recorded by the visual measurement system.

[0027] According to the present invention, a method for testing the buckling performance of a flexible telescopic rod includes the following steps: S1. Install loading device 1 and connect loading device 1 to support platform 7 via guide rod 2.

[0028] S2. Install the connecting block 6 onto the loading device 1 and the support platform 7 respectively using fasteners.

[0029] S3. Connect the rod fixing joint 4 to the end of the sample 3 by adhesive bonding or screwing.

[0030] S4. Use pins to connect the rod fixing joint 4 to the corresponding connecting block 6.

[0031] S5. If the loading boundary condition is a hinged constraint, do not install limit block 5; if the loading boundary condition is a fixed constraint, install limit block 5.

[0032] S6. Calibrate the visual measurement device 8.

[0033] S7. Start the visual measurement device 8 and record image data.

[0034] S8. Start the loading device 1 to apply a compressive load to the sample 3, and record the loading load and displacement value through the sensor.

[0035] S9. Loading to specimen 3 resulted in buckling instability. The buckling load was obtained through loading device 1, and the buckling deformation characteristics were obtained through visual measurement device 8. It should be noted that buckling instability refers to the phenomenon where a slender rod, under axial pressure, suddenly undergoes lateral bending deformation (rather than material strength failure) and loses its load-bearing capacity when the pressure reaches a certain critical value. The core concept is "load-bearing failure caused by abrupt shape changes," and the judgment is based on two criteria: abrupt shape changes and a sudden drop in load.

[0036] There are two characteristics of instability deformation: one is a sudden drop in the force sensor (load), and the other is a sudden change in shape, with large deformation occurring in areas with weak performance. Information extraction from the visual testing system: The product shape is fitted from a photograph, and the deformation is determined by subsequent changes in the shape.

[0037] S10. Close the loading device 1 and the visual measurement device 8.

[0038] It should be further noted that the technical solution of this application can be applied to the performance testing and verification of products such as flexible antennas and flexible deployment mechanisms.

[0039] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0040] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A flexible telescopic rod buckling performance testing system, characterized in that, It includes a loading device (1), a guide rod (2), a sample (3), a rod fixing joint (4), a limiting block (5), a connecting block (6), a support platform (7), and a visual measurement device (8); The guide rod (2) is fixedly installed between the loading device (1) and the support platform (7). The rod fixing joint (4) is provided at both ends of the sample (3). The connecting block (6) is fixedly installed on the side wall of the loading device (1) facing the support platform (7) and the side wall of the support platform (7) facing the loading device (1). The rod fixing joint (4) at one end of the specimen (3) is hinged to the connecting block (6) on the loading device (1) by a pin, and the rod fixing joint (4) at the other end of the specimen (3) is hinged to the connecting block (6) on the support platform (7) by a pin. A limiting block (5) is installed between the connecting block (6) on the loading device (1) and the rod fixing joint (4) to fix the connecting block (6) on the loading device (1) and the rod fixing joint (4) respectively. The limiting block (5) is installed between the connecting block (6) on the support platform (7) and the rod fixing joint (4) or no limiting block (5) is installed. The visual measurement device (8) is located beside the loading device (1) and is used to record the deformation of the rod.

2. The flexible telescopic rod buckling performance testing system as described in claim 1, characterized in that, If the sample (3) is a cantilever beam structure, a limiting block (5) is installed between the connecting block (6) on the support platform (7) and the rod fixing joint (4) so ​​that the connecting block (6) on the support platform (7) and the rod fixing joint (4) are relatively fixed. If the sample (3) is a rod structure, no limiting block (5) is installed between the connecting block (6) on the support platform (7) and the rod fixing joint (4), so that the connecting block (6) on the support platform (7) and the rod fixing joint (4) are hinged and constrained.

3. The flexible telescopic rod buckling performance testing system as described in claim 1, characterized in that, The shape and fixing form of the connection interface between the rod fixing joint (4) and the specimen (3) are matched according to the actual shape and interface position of the specimen (3).

4. The flexible telescopic rod buckling performance testing system as described in claim 1, characterized in that, The loading device (1) includes a hydraulic loading system and a force displacement sensor, which pressurizes the sample (3) and measures and records the force and displacement values ​​during the loading process.

5. The flexible telescopic rod buckling performance testing system as described in claim 1, characterized in that, The guide rod (2) is provided on both sides of the sample (3) to ensure that the loading direction is perpendicular.

6. The flexible telescopic rod buckling performance testing system as described in claim 1, characterized in that, The visual measurement device (8) includes two measuring cameras, which are placed orthogonally.

7. The flexible telescopic rod buckling performance testing system as described in claim 1, characterized in that, The connecting block (6) is provided with a hinge seat, and the rod fixing joint (4) is provided with a hinge joint on the side away from the sample (3). The hinge joint is hinged to the hinge seat by a pin.

8. The flexible telescopic rod buckling performance testing system as described in claim 7, characterized in that, The hinge axis of the connecting block (6) and the rod fixing joint (4) is parallel to the radial direction of the specimen (3).

9. The flexible telescopic rod buckling performance testing system as described in claim 7, characterized in that, The shape of the limiting block (5) allows the limiting block (5) to engage with the hinge seat on the connecting block (6), and the limiting block (5) engaged with the hinge seat on the connecting block (6) abuts against the rod fixing joint (4).

10. A method for testing the buckling performance of a flexible telescopic rod, characterized in that, The buckling performance testing system for flexible telescopic rods according to any one of claims 1 to 9 includes the following steps: S1. Install the loading device (1) and connect the loading device (1) to the support platform (7) via the guide rod (2); S2. Install the connecting block (6) onto the loading device (1) and the support platform (7) respectively using fasteners. S3. Connect the rod fixing joint (4) to the end of the specimen (3) by adhesive bonding or screwing. S4. Use pins to connect the rod fixing joint (4) to the corresponding connecting block (6); S5. If the loading boundary condition is a hinged constraint, do not install the limit block (5). If the loading boundary condition is a fixed constraint, install the limit block (5). S6. Calibrate the visual measurement equipment (8); S7. Start the visual measurement device (8) and record the image data; S8. Start the loading device (1) to apply a compressive load to the sample (3) and record the loading load and displacement value through the sensor; S9. Loading the specimen (3) causes buckling instability. The buckling load is obtained through the loading device (1), and the buckling deformation characteristics are obtained through the visual measurement device (8). S10. Close the loading device (1) and the visual measurement device (8).

Images