Mechanical property testing device and testing method

Abstract

The invention discloses a mechanical property testing device and a testing method, and relates to the technical field of mechanical property testing. The testing device comprises a first clamp, a second clamp, a force sensor, a force application device, a displacement sensor and a control device. Each of the first clamp and the second clamp comprises a sleeve, an expansion sleeve and a lining, the expansion sleeve is located in the sleeve, and the outer wall of the expansion sleeve is matched with the conical surface of the inner wall of the sleeve; the lining is located in the expansion sleeve, an annular area used for clamping the end of a to-be-tested piece is defined between the outer wall of the lining and the inner wall of the expansion sleeve, and the outer wall of the expansion sleeve moves along the conical surface relative to the inner wall of the sleeve and can clamp the to-be-tested piece; the testing method comprises the following steps: applying force to a to-be-tested piece by using a force applying device; the control device receives the stress data and the displacement data, converts the stress data and the displacement data into a stress-strain relationship, and obtains mechanical property parameters of the to-be-tested piece according to the stress-strain relationship. The curved-surface thin-wall test piece can be stably clamped, and the requirement for high-precision mechanical property testing is met.

Description

Technical Field

[0001] This invention relates to the field of mechanical performance testing technology, and in particular to a mechanical performance testing device and testing method. Background Technology

[0002] In the field of materials mechanical property testing, tensile testing of curved thin-walled specimens is an important means of evaluating their mechanical properties such as elastic modulus, yield strength, and tensile strength. However, current devices used for testing the mechanical properties of curved thin-walled specimens cannot effectively clamp the specimens, leading to many inaccuracies in the analysis of the performance of curved thin-walled structures.

[0003] In view of the problems of the prior art, those skilled in the art urgently need a mechanical property testing device and method to meet the mechanical property testing requirements of curved thin-walled specimens. Summary of the Invention

[0004] The purpose of this invention is to provide a mechanical property testing device and method to solve the problems existing in the prior art, and to stably clamp curved thin-walled specimens to meet the requirements of high-precision mechanical property testing.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a mechanical property testing device, comprising a first clamp, a second clamp, a force sensor, a force application device, a displacement sensor, and a control device. Both the first clamp and the second clamp include a sleeve, an expansion sleeve, and a bushing. The expansion sleeve is located inside the sleeve, and its outer wall mates with the conical surface of the inner wall of the sleeve. The bushing is located inside the expansion sleeve, and its outer wall and the inner wall of the expansion sleeve form an annular region for clamping the end of the test piece. The outer wall of the expansion sleeve can move relative to the inner wall of the sleeve along the conical surface to clamp the test piece. One end of the force sensor is connected to the force application device, and the other end is connected to either the first clamp or the second clamp. The displacement sensor is used to detect the displacement caused by the deformation of the test piece under force. The force sensor, the displacement sensor, and the force application device are all electrically connected to the control device.

[0007] In some embodiments, the inner wall of the sleeve is formed with an inner conical surface and a stepped portion, wherein the end of the inner conical surface near the stepped portion is a first large diameter end and the other end away from the stepped portion is a first small diameter end; the outer wall of the expansion sleeve is formed with an outer conical surface and an annular flange, wherein the end of the outer conical surface near the annular flange is a second large diameter end and the other end away from the annular flange is a second small diameter end; the annular flange and the stepped portion are connected by fasteners, and the fasteners are capable of driving the outer conical surface of the expansion sleeve to move relative to the inner conical surface of the sleeve.

[0008] In some embodiments, the inner wall of the expansion sleeve is provided with a plurality of expansion and contraction compensation grooves extending along its axial direction.

[0009] In some embodiments, the circumferential edge of one end of the outer wall of the bushing protrudes outward to form a guide ring; the guide ring abuts against the inner wall of the expansion sleeve, and the inner wall of the expansion sleeve, the guide ring, and the outer wall of the bushing form the annular region.

[0010] In some embodiments, both the inner wall of the expansion sleeve and the outer wall of the bushing are provided with multiple anti-slip grooves extending circumferentially.

[0011] In some embodiments, a fixing frame is also included, comprising a first support beam, a second support beam, a support plate, a fixing ring, and a sensor mounting plate; the force application device is mounted on the first support beam, and the telescopic shaft of the force application device passes through the first support beam and is connected to one end of the force sensor; the second support beam is perpendicular to the first support beam, and one end of the sensor mounting plate is fixedly connected to the second support beam, while the other end is a cantilever end; the displacement sensor is mounted on the sensor mounting plate, and the transmitting end of the displacement sensor is disposed opposite to the end of the first clamp; the support plate is disposed opposite to the first support beam, and the fixing ring is disposed on the support plate, and one end of the sleeve of the second clamp is connected to the fixing ring.

[0012] In some embodiments, the control device includes a data acquisition transmitter and a host computer; the force sensor, the displacement sensor and the force application device are all electrically connected to the data acquisition transmitter via a wiring harness, and the data acquisition transmitter is electrically connected to the host computer via a wiring harness.

[0013] In some embodiments, the force sensor is an S-type force sensor, the displacement sensor is a laser displacement sensor, and the force application device is an electric cylinder.

[0014] In some embodiments, the first clamp further includes a connector; the connector includes a connecting rod and a disk, one end of the connecting rod is integrally connected to the side of the disk, and the other end is threadedly connected to one end of the force sensor; the outer peripheral wall of the disk is threadedly connected to one end of the sleeve of the first clamp, and the disk has a plurality of through-holes for weight reduction.

[0015] This invention also provides a mechanical property testing method using the aforementioned mechanical property testing device. The method includes: clamping both ends of the test piece in the annular regions of a first clamp and a second clamp, such that the outer wall of the expansion sleeve moves relative to the inner wall of the sleeve along a conical surface to clamp the ends of the test piece; applying force to the test piece using a force application device; a force sensor detecting the force data of the test piece and sending it to a control device; a displacement sensor detecting the displacement data of the test piece under force deformation and sending it to the control device; the control device receiving the force data and the displacement data and converting them into a stress-strain relationship, and obtaining the mechanical property parameters of the test piece based on the stress-strain relationship.

[0016] The present invention achieves the following technical effects compared to the prior art:

[0017] The mechanical property testing device and method of the present invention utilize a first clamp and a second clamp to clamp the two ends of the test piece, respectively. Both the first clamp and the second clamp include a sleeve, an expansion sleeve, and a bushing. The outer wall of the expansion sleeve and the inner wall of the sleeve form a conical fit. The annular area between the inner wall of the expansion sleeve and the outer wall of the bushing is used to clamp the ends of the test piece. When the expansion sleeve moves relative to the sleeve, the conical surface causes the expansion sleeve to be compressed, thereby clamping the test piece and achieving stable clamping of the curved thin-walled specimen. Furthermore, a force-applying device applies force to the test piece. A force sensor detects the force data of the test piece and sends it to a control device, while a displacement sensor detects the displacement data of the test piece after deformation under force and sends it to the control device. The control device can then obtain the mechanical property parameters of the test piece based on the force and displacement data, meeting the requirements for high-precision mechanical property testing. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the mechanical performance testing device in some embodiments of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the fixing frame in some embodiments of the present invention;

[0021] Figure 3 This is a schematic diagram of the structure of the test piece in some embodiments of the present invention;

[0022] Figure 4This is a schematic diagram showing the connection between the first fixture and the test piece in some embodiments of the present invention;

[0023] Figure 5 This is a cross-sectional view showing the connection between the first fixture and the test piece in some embodiments of the present invention;

[0024] Figure 6 This is a three-dimensional structural diagram of the bushing in some embodiments of the present invention;

[0025] Figure 7 This is a cross-sectional view of the bushing in some embodiments of the present invention;

[0026] Figure 8 This is a three-dimensional structural diagram of the expansion sleeve in some embodiments of the present invention;

[0027] Figure 9 This is a cross-sectional view of the expansion sleeve in some embodiments of the present invention;

[0028] Figure 10 This is a three-dimensional structural diagram of the sleeve in some embodiments of the present invention;

[0029] Figure 11 This is a cross-sectional view of the sleeve in some embodiments of the present invention;

[0030] Figure 12 This is a three-dimensional structural diagram of the connector in some embodiments of the present invention;

[0031] Figure 13 This is a cross-sectional view of a connector in some embodiments of the present invention;

[0032] Figure 14 This is a schematic diagram of the force sensor structure in some embodiments of the present invention;

[0033] Figure 15 This is a schematic diagram showing the connection between the second fixture and the test piece in some embodiments of the present invention;

[0034] Figure 16 This is a cross-sectional view showing the connection between the second clamp and the test piece in some embodiments of the present invention;

[0035] Figure 17 This is a flowchart illustrating the main steps of the mechanical performance testing method in some embodiments of the present invention.

[0036] In the diagram: 1-Fixed frame; 2-Test piece; 3-First clamp; 4-Force sensor; 5-Force application device; 6-Displacement sensor; 7-Second clamp; 8-Data acquisition and transmission device; 9-Host computer; 11-First support beam; 12-Through hole; 13-Light transmission hole; 14-Sensor mounting plate; 15-Fixing ring; 16-Second support beam; 17-Support plate; 31-Sleeve; 32-Fastener; 33-Expansion sleeve; 34-Bushing; 35-Connector; 41 - First threaded hole; 42 - Second threaded hole; 100 - First wire harness; 101 - Second wire harness; 102 - Third wire harness; 103 - Fourth wire harness; 311 - Threaded part; 312 - Third threaded hole; 313 - Inner conical surface; 331 - Annular flange; 332 - Mounting hole; 333 - First anti-slip groove; 334 - Expansion compensation groove; 335 - Outer conical surface; 341 - Second anti-slip groove; 342 - Guide ring; 351 - Connecting rod; 352 - Disc. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The purpose of this invention is to provide a mechanical property testing device and method to solve the problems existing in the prior art, which can stably clamp curved thin-walled specimens and meet the needs of high-precision mechanical property testing.

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] This invention provides a mechanical property testing device, such as... Figures 1 to 16 As shown, the device includes a first clamp 3, a second clamp 7, a force sensor 4, a force application device 5, a displacement sensor 6, and a control device. The first clamp 3 and the second clamp 7 have roughly the same structure, both including a sleeve 31, an expansion sleeve 33, and a bushing 34. The expansion sleeve 33 has a conical annular structure and is located inside the sleeve 31. The outer wall of the expansion sleeve 33 has an outer conical surface, and the inner wall of the sleeve 31 has an inner conical surface. The outer wall of the expansion sleeve 33 and the inner wall of the sleeve 31 form a conical surface fit. The bushing 34 has a cylindrical structure and is located inside the expansion sleeve 33. The outer wall of the bushing 34 and the inner wall of the expansion sleeve 33 form an annular area, which is used to clamp the test piece 2.

[0041] One end of the force sensor 4 is connected and fixed to the force application device 5, and the other end is connected and fixed to the first clamp 3 or the second clamp 7. The force application device 5 is used to apply force to the test piece 2, and the force sensor 4 is used to detect the magnitude of the applied force. The displacement sensor 6 is used to detect the displacement caused by the deformation of the test piece 2 under force. Furthermore, the force sensor 4, the displacement sensor 6, and the force application device 5 are all electrically connected to the control device.

[0042] It should be noted that the appendix of this invention... Figure 1 The first clamp 3 and the second clamp 7 are arranged opposite each other in the vertical direction, and the force-applying device 5 applies an axial tensile force to the first clamp 3; those skilled in the art can also arrange the first clamp 3 and the second clamp 7 opposite each other in the horizontal direction. In this case, the force-applying device 5 can apply an axial force to the first clamp 3 and / or the second clamp 7; that is, those skilled in the art can specifically set the arrangement and force-applying method of the first clamp 3 and the second clamp 7, and the present invention does not specifically limit this.

[0043] In some embodiments, such as Figure 10 and Figure 11 As shown, the inner wall of the sleeve 31 has an inner conical surface 313 and a stepped portion. The surface of the stepped portion is recessed inward to form a third threaded hole 312. The end of the inner conical surface 313 near the surface of the stepped portion is the first large diameter end, and the end away from the surface of the stepped portion is the first small diameter end.

[0044] like Figure 8 and Figure 9 As shown, the outer wall of the expansion sleeve 33 is formed with an outer conical surface 335 and an annular flange 331. The end of the outer conical surface 335 near the annular flange 331 is the second large diameter end, and the other end away from the annular flange 331 is the second small diameter end.

[0045] like Figure 5 and Figure 16 As shown, the annular flange 331 and the stepped portion are connected by a fastener 32. The fastener 32 passes through the mounting hole 332 on the annular flange 331 and is threaded into the third threaded hole 312. By tightening the fastener 32, the outer conical surface 335 of the outer wall of the expansion sleeve 33 can move relative to the inner conical surface 313 of the sleeve 31 in the direction from the large diameter end to the small diameter end. Here, the direction from the large diameter end to the small diameter end refers to the axial direction from the second large diameter end to the second small diameter end of the outer conical surface 335 or the axial direction from the first large diameter end to the first small diameter end of the inner conical surface 313. The inner conical surface 313 and the outer conical surface 335 are matched, that is, they have the same inclination angle.

[0046] It should be noted that the end of the test piece 2 has an arc-shaped structure and is adapted to be clamped in the annular area between the expansion sleeve 33 and the bushing 34. During the process of the expansion sleeve 33 moving relative to the sleeve 31 along the conical surface, the expansion sleeve 33 is squeezed by the conical surface of the sleeve 31 and tends to shrink inward. This allows the expansion sleeve 33 to gradually clamp the arc-shaped end of the test piece 2 during the movement, achieving the effect of stable clamping of the curved thin-walled test piece.

[0047] In some embodiments, such as Figure 8 and Figure 9 As shown, multiple expansion and contraction compensation grooves 334 extending axially along the inner wall of the expansion sleeve 33 are provided.

[0048] It should be noted that the present invention uses expansion and contraction compensation grooves 334 to compensate for the deformation of the expansion sleeve 33. That is, as the expansion sleeve 33 moves along the conical surface, the size of the conical surface gradually decreases, causing the expansion sleeve 33 to deform. By setting expansion and contraction compensation grooves 334, the deformation can be made to occur at the expansion and contraction compensation grooves 334, thereby compensating for the amount of extrusion deformation of the expansion sleeve 33. Those skilled in the art can specifically set the number of expansion and contraction compensation grooves 334, and those skilled in the art can also specifically set the groove depth or groove width of the expansion and contraction compensation grooves 334 to gradually change along the length direction or to be a fixed size. The present invention does not make specific limitations in these respects.

[0049] In some embodiments, such as Figure 6 and Figure 7 As shown, the circumferential edge of one end of the outer wall of the bushing 34 protrudes outward to form a guide ring 342; as Figure 5 As shown, the guide ring 342 abuts against the inner wall of the expansion sleeve 33, and the inner wall of the expansion sleeve 33, the outer wall of the bushing 34, and the guide ring 342 form an annular area; one end of the annular area is open for the insertion of the end of the test piece 2.

[0050] It should be noted that the present invention uses the guide ring 342 to provide support and ensure that the expansion sleeve 33 moves axially; and the annular area is adapted to the end arc structure of the test piece 2.

[0051] In some embodiments, both the inner wall of the expansion sleeve 33 and the outer wall of the bushing 34 are provided with multiple anti-slip grooves extending circumferentially. For example... Figure 9 As shown, the inner wall of the expansion sleeve 33 is provided with multiple first anti-slip grooves 333 at the corresponding annular areas; as Figure 7 As shown, the outer wall of the bushing 34 is provided with multiple second anti-slip grooves 341 at the corresponding annular area. The present invention can increase the contact friction between the bushing 34 and the test piece 2 by providing anti-slip grooves.

[0052] Furthermore, the two side walls of the anti-slip groove are a plane and an inclined plane, respectively. The plane is perpendicular to the inner wall of the expansion sleeve 33 or the outer wall of the bushing 34 to form a pointed structure. This pointed structure can prevent the test piece 2 from sliding and increase the contact friction.

[0053] In some embodiments, the testing apparatus of the present invention further includes a mounting bracket 1, such as... Figure 2 As shown, the mounting bracket 1 includes a first support beam 11, a second support beam 16, a support plate 17, a fixing ring 15, and a sensor mounting plate 14; wherein, the first support beam 11 is arranged opposite to the support plate 17, the second support beam 16 is arranged perpendicularly to both the first support beam 11 and the support plate 17, the support plate 17 is provided with a fixing ring 15, one end of the sensor mounting plate 14 is connected and fixed to the second support beam 16, and the other end is a cantilever end.

[0054] A force-applying device 5 is installed on the first support beam 11, and a through hole 12 is provided on the first support beam 11. The first force-applying device 5 has a telescopic shaft, and the telescopic shaft passes through the through hole 12 on the first support beam 11 and is connected to one end of the force sensor 4.

[0055] The sensor mounting plate 14 has a light-transmitting hole 13. The displacement sensor 6 is mounted on the sensor mounting plate 14. This displacement sensor 6 is a laser displacement sensor. The laser emitted by the laser displacement sensor shines through the light-transmitting hole 13 onto the end of the first clamp 3. When the test piece 2 is subjected to force and deforms, causing displacement, the first clamp 3 also moves accordingly. The displacement data can be detected by the laser displacement sensor. Here, the end of the first clamp 3 refers to the end of the first clamp 3 that is closer to the second clamp 7.

[0056] One end of the sleeve 31 is a threaded part 311, and the threaded part 311 of the sleeve 31 of the second clamp 7 is threadedly connected and fixed to the retaining ring 15.

[0057] In some embodiments, such as Figure 4 , Figure 12 and Figure 13 As shown, the first clamp 3 also includes a connector 35, which includes a connecting rod 351 and a disc 352. One end of the connecting rod 351 is integrally connected to the side of the disc 352, and the other end is threadedly connected to one end of the force sensor 4. The outer peripheral wall of the disc 352 is provided with an external thread and is threadedly connected to the threaded portion 311 of the sleeve 31 of the first clamp 3. The disc 352 is provided with a plurality of weight reduction holes that pass through it.

[0058] like Figure 14 As shown, the force sensor 4 is an S-type force sensor. The two ends of the S-type force sensor are respectively provided with a first threaded hole 41 and a second threaded hole 42. One end of the connecting rod 351 and the telescopic end of the force application device 5 are respectively threadedly connected and fixed to the first threaded hole 41 and the second threaded hole 42.

[0059] In some embodiments, such as Figure 1 As shown, the control device includes a data acquisition and transmission unit 8 and a host computer 9; the force application device 5 is electrically connected to the data acquisition and transmission unit 8 through a first wiring harness 100, the force sensor 4 is electrically connected to the data acquisition and transmission unit 8 through a second wiring harness 101, the displacement sensor 6 is electrically connected to the data acquisition and transmission unit 8 through a third wiring harness 102, and the data acquisition and transmission unit 8 is electrically connected to the host computer 9 through a fourth wiring harness 103.

[0060] In some embodiments, the force-applying device 5 of the present invention is an electric cylinder.

[0061] like Figure 17 As shown, the present invention provides a mechanical property testing method, which uses the above-mentioned mechanical property testing device and includes the following steps:

[0062] Step S1: Clamp both ends of the test piece 2 in the annular area of ​​the first clamp 3 and the second clamp 7 respectively, and make the outer wall of the expansion sleeve 33 move relative to the inner wall of the sleeve 31 along the conical surface to clamp the end of the test piece 2.

[0063] Step S2: Apply force to the test piece 2 using the force application device 5, the force sensor 4 detects the force data of the test piece 2 and sends it to the control device, and the displacement sensor 6 detects the displacement data of the test piece 2 under force deformation and sends it to the control device.

[0064] Step S3: The control device receives the force data and displacement data and converts them into stress-strain relationship, and obtains the mechanical performance parameters of the test piece 2 based on the stress-strain relationship.

[0065] In some embodiments, in step S1 above, the two ends of the test piece 2 are respectively clamped in the annular area between the expansion sleeve 33 and the bushing 34 of the first clamp 3 and the second clamp 7, and the fastener 32 is tightened. The outer conical surface 335 of the expansion sleeve 33 and the inner conical surface 313 of the sleeve 31 cooperate, and the expansion and contraction compensation groove 334 of the expansion sleeve 33 compensates for the deformation of the expansion sleeve 33, clamping the two ends of the test piece 2. The guide ring 342 of the bushing 34 plays a supporting role to ensure that the expansion sleeve 33 moves axially. The second anti-slip groove 341 of the bushing 34 and the first anti-slip groove 333 of the expansion sleeve 33 prevent the ends of the test piece 2 from sliding.

[0066] In some embodiments, in step S2 above, the host computer 9 of the control device starts the electric cylinder to retract, the S-shaped force sensor senses the real-time tension, and the laser displacement sensor measures the real-time change of displacement of the tensile deformation of the test piece 2 through the light-transmitting hole 13 and transmits it to the host computer 9.

[0067] In some embodiments, in step S3 above, the host computer 9 synchronously converts the collected tensile and displacement data into stress-strain relationships, thereby testing the mechanical property parameters such as elastic modulus, yield strength and tensile strength of the curved thin-walled circular tube specimen, i.e., the test specimen 2.

[0068] This invention employs a clamping and tensile device, a control system, and a data analysis system to achieve real-time acquisition and analysis of the mechanical properties of curved thin-walled specimens. This invention has the following technical advantages:

[0069] It has a simple structure, can be miniaturized, and is easy to maintain;

[0070] The fixture is used in curved thin-walled structures;

[0071] Self-locking clamping design ensures high reliability;

[0072] Low cost and high precision;

[0073] Intelligent control ensures high testing efficiency.

[0074] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A mechanical property testing device, characterized in that, It includes a first clamp, a second clamp, a force sensor, a force application device, a displacement sensor, and a control device; Both the first clamp and the second clamp include a sleeve, an expansion sleeve, and a bushing. The expansion sleeve is located inside the sleeve, and the outer wall of the expansion sleeve mates with the conical surface of the inner wall of the sleeve. The bushing is located inside the expansion sleeve, and the outer wall of the bushing and the inner wall of the expansion sleeve form an annular area for clamping the end of the test piece. The outer wall of the expansion sleeve can move relative to the inner wall of the sleeve along the conical surface to clamp the test piece. One end of the force sensor is connected to the force application device, and the other end is connected to the first clamp or the second clamp. The displacement sensor is used to detect the displacement caused by the deformation of the test piece under force. The force sensor, the displacement sensor, and the force application device are all electrically connected to the control device.

2. The mechanical property testing device according to claim 1, characterized in that, The inner wall of the sleeve is formed with an inner conical surface and a stepped portion. The end of the inner conical surface near the stepped portion is the first large diameter end, and the other end away from the stepped portion is the first small diameter end. The outer wall of the expansion sleeve is formed with an outer conical surface and an annular flange. The end of the outer conical surface near the annular flange is the second large diameter end, and the other end away from the annular flange is the second small diameter end. The annular flange is connected to the stepped portion by a fastener, and the fastener can drive the outer conical surface of the expansion sleeve to move relative to the inner conical surface of the sleeve.

3. The mechanical property testing device according to claim 1, characterized in that, The inner wall of the expansion sleeve is provided with multiple expansion and contraction compensation grooves extending along its axial direction.

4. The mechanical property testing device according to claim 1, characterized in that, The circumferential edge of one end of the outer wall of the bushing protrudes outward to form a guide ring; The guide ring abuts against the inner wall of the expansion sleeve, and the inner wall of the expansion sleeve, the guide ring, and the outer wall of the bushing form the annular region.

5. The mechanical property testing device according to claim 1, characterized in that, The inner wall of the expansion sleeve and the outer wall of the bushing are both provided with multiple anti-slip grooves extending circumferentially.

6. The mechanical property testing device according to claim 1, characterized in that, It also includes a fixing frame, which includes a first support beam, a second support beam, a support plate, a fixing ring, and a sensor mounting plate; The force-applying device is installed on the first support beam, and the telescopic shaft of the force-applying device passes through the first support beam and is connected to one end of the force sensor; The second support beam is perpendicular to the first support beam, and one end of the sensor mounting plate is connected and fixed to the second support beam, while the other end is a cantilever end. The displacement sensor is mounted on the sensor mounting plate, and the transmitting end of the displacement sensor is positioned opposite to the end of the first clamp. The support plate is disposed opposite to the first support beam, the support plate is provided with the fixing ring, and one end of the sleeve of the second clamp is connected to the fixing ring.

7. The mechanical property testing device according to claim 1, characterized in that, The control device includes a data acquisition and transmission unit and a host computer; The force sensor, the displacement sensor, and the force application device are all electrically connected to the data acquisition and transmission device via a wiring harness, and the data acquisition and transmission device is electrically connected to the host computer via a wiring harness.

8. The mechanical property testing device according to claim 1, characterized in that, The force sensor is an S-type force sensor, the displacement sensor is a laser displacement sensor, and the force application device is an electric cylinder.

9. The mechanical property testing device according to claim 6, characterized in that, The first clamp also includes a connector; The connector includes a connecting rod and a disk. One end of the connecting rod is integrally connected to the side of the disk, and the other end is threadedly connected to one end of the force sensor. The outer peripheral wall of the disk is threaded to one end of the sleeve of the first clamp, and the disk has multiple weight-reducing holes that pass through it.

10. A method for testing mechanical properties, characterized in that, The method using the mechanical property testing apparatus according to any one of claims 1-9 includes: The two ends of the test piece are respectively clamped in the annular areas of the first clamp and the second clamp, and the outer wall of the expansion sleeve moves relative to the inner wall of the sleeve along the conical surface to clamp the ends of the test piece. A force is applied to the test piece using a force application device. A force sensor detects the force data of the test piece and sends it to a control device. A displacement sensor detects the displacement data of the test piece under force deformation and sends it to the control device. The control device receives the force data and the displacement data and converts them into a stress-strain relationship, and obtains the mechanical performance parameters of the test piece based on the stress-strain relationship.

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