Multi-functional small punch test device and method

Abstract

A multi-functional small punch test device and method. The device comprises: a driving unit, a loading unit, a first fixing unit (3), a second fixing unit (6), a third fixing unit, a detection unit, a temperature control unit and a control unit, wherein the driving unit drives, on the basis of a driving signal, the loading unit to move; the first fixing unit (3) fixes the loading unit, and the second fixing unit (6) cooperates with the third fixing unit to fix a circular sample (10); the detection unit performs force displacement detection on a sample to be pressed, the sample to be pressed including a plurality of punch balls; and the temperature control unit executes temperature adjustment control on the basis of a control signal which is output by the control unit. In a single test, mechanical property parameters of materials are determined on the basis of a plurality of sets of data, which has high reliability. In addition, the problem of the monotonous test temperature for existing fixtures can be solved, and the mechanical property parameters of a plurality of materials at a specific temperature can also be acquired in a single test, which prevents repeated tests and significantly improves the test efficiency.

Description

A multifunctional small punch test device and method TECHNICAL FIELD

[0001] The present application relates to the technical field of mechanical property testing of metal materials, and more particularly to a multifunctional small punch test device and method. BACKGROUND

[0002] With the increasing demand for energy, oil and gas pipelines and pressure vessels and other equipment as important energy mechanical structures, their integrity and safety during service are increasingly concerned. These devices are long-term served in high pressure, high temperature, deep sea low temperature and corrosive environment, and cannot avoid the deterioration of mechanical property parameters. Therefore, the mechanical property parameters under high temperature or low temperature environment are an important indicator for evaluating the safety performance of important equipment structures, and the deterioration of the mechanical property parameters of materials under different temperature environments needs to be accurately tested and evaluated.

[0003] The existing small punch test device has the following defects:

[0004] 1. The existing small punch test device obtains the load-displacement curve of the material through a single test, and then extracts the values of specific points on the curve to determine the mechanical property parameters of the material according to the empirical formula, which has relatively low reliability, and the applicable range of the empirical formula is relatively limited, which limits the application range of the small punch test device;

[0005] 2. The existing small punch test device needs to constantly repeat the test when testing the mechanical properties of a certain material under different temperature conditions, which has relatively low efficiency;

[0006] 3. The existing small punch test device also needs to repeat the test multiple times when testing the mechanical properties of different materials under the same temperature condition, which affects the experimental efficiency. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a multifunctional small punch test device and method in view of the problems in the prior art.

[0008] The technical scheme adopted by the present application to solve the technical problem is to construct a multifunctional small punch test device, comprising: a driving unit, a loading unit, a first fixing unit, a second fixing unit, a third fixing unit, a detection unit, a temperature control unit and a control unit;

[0009] The driving unit is connected with the loading unit and is used to drive the loading unit to move according to the driving signal;

[0010] The first fixing unit, the second fixing unit and the third fixing unit are arranged from top to bottom along the axial direction, the first fixing unit is used for fixing the loading unit, the second fixing unit cooperates with the third fixing unit to fix the circular sample; the detection unit is installed on the loading unit and located between the first fixing unit and the second fixing unit; the detection unit is used for detecting the force displacement of the sample to be pressed when the loading unit presses the sample to be pressed and outputting a detection signal to the control unit; the sample to be pressed includes a plurality of impact balls.

[0011] The temperature control unit is connected with the control unit and is used for performing temperature adjustment control according to the control signal output by the control unit.

[0012] In the multifunctional small punch experimental device, the loading unit includes a main loading rod and a plurality of impact ball loading rods.

[0013] The main loading rod and the plurality of impact ball loading rods are arranged on the first fixing unit, and the main loading rod is connected with the driving unit.

[0014] The main loading rod moves according to the driving of the driving unit and drives the plurality of impact ball loading rods and the detection unit to move, so as to press the plurality of impact balls placed below the detection unit.

[0015] In the multifunctional small punch experimental device, the first fixing unit includes a plurality of first threaded holes corresponding to the plurality of impact ball loading rods; and the detection unit includes a plurality of force displacement sensors corresponding to the plurality of impact ball loading rods.

[0016] The plurality of first threaded holes are arranged uniformly in the circumferential direction, and the first threaded hole cooperates with the thread on the cylindrical surface of the impact ball loading rod.

[0017] Each force displacement sensor is arranged below the corresponding impact ball loading rod.

[0018] In the multifunctional small punch experimental device, the second fixing unit includes a plurality of through holes corresponding to the plurality of impact ball loading rods.

[0019] The plurality of through holes are arranged uniformly in the circumferential direction, and each through hole is used for allowing the corresponding impact ball loading rod and impact ball to pass through.

[0020] In the multifunctional small punch experimental device, a plurality of first positioning holes and a plurality of second threaded holes are arranged around each through hole.

[0021] The third fixing unit comprises a plurality of fixing devices corresponding to the plurality of through holes;

[0022] Each of the fixing devices is a barrel structure, and a center hole is arranged at the center of the cylindrical barrel structure, and a plurality of second positioning holes and a plurality of third threaded holes are arranged on the upper surface of the barrel structure;

[0023] The plurality of second positioning holes are arranged corresponding to the plurality of first positioning holes, and the plurality of third threaded holes are arranged corresponding to the plurality of second threaded holes;

[0024] The plurality of second positioning holes and the plurality of first positioning holes are matched to allow a positioning pin to pass through and fix the positioning pin;

[0025] The plurality of second threaded holes and the plurality of third threaded holes are matched to allow a connecting screw to pass through and connect the second fixing unit and the third fixing unit to clamp the circular sample between the second fixing unit and the third fixing unit.

[0026] In the multifunctional small punch experimental device, the temperature control unit comprises a plurality of temperature control modules;

[0027] The plurality of temperature control modules are arranged corresponding to the plurality of punch ball loading rods and are respectively used for temperature adjustment.

[0028] In the multifunctional small punch experimental device, each of the temperature control modules comprises a temperature control box, an electric heating wire and a temperature sensor;

[0029] The temperature control box is arranged below the corresponding fixing device, and the electric heating wire and the temperature sensor are arranged inside the temperature control box;

[0030] The electric heating wire is connected with the control unit and is used for on / off control according to the control unit;

[0031] The temperature sensor is used for detecting the temperature in the temperature control box and outputting a temperature detection signal to the control unit.

[0032] In the multifunctional small punch experimental device, each of the temperature control modules further comprises a cooling liquid delivery hole;

[0033] The cooling liquid delivery hole is arranged on the temperature box and is used for delivering cooling liquid into the temperature control box.

[0034] In the multifunctional small punch experimental device, the center of the first threaded hole on the first fixing unit, the through hole on the second fixing unit and the center hole on the third fixing unit are located on the same axis.

[0035] The application also provides a multifunctional small punch experimental method, which is applied to the multifunctional small punch experimental device and comprises the following steps:

[0036] constructing a small punch experimental model;

[0037] obtaining input parameters and a load of the experiment;

[0038] performing simulation calculation based on the input parameters and the load of the experiment to obtain a plurality of simulated force-displacement curves;

[0039] performing a small punch experiment;

[0040] recording experimental data during the experiment;

[0041] performing analysis according to the experimental data to obtain a plurality of experimental force-displacement curves;

[0042] judging whether the simulated force-displacement curves match the plurality of experimental force-displacement curves;

[0043] if the simulated force-displacement curves match the plurality of experimental force-displacement curves, determining material mechanical property parameters;

[0044] if the simulated force-displacement curves do not match the plurality of experimental force-displacement curves, adjusting the input parameters and continuing the simulation calculation until the simulated force-displacement curves match the plurality of experimental force-displacement curves.

[0045] The multifunctional small punch experimental device and method have the following beneficial effects: the device comprises a driving unit, a loading unit, a first fixing unit, a second fixing unit, a third fixing unit, a detection unit, a temperature control unit and a control unit; the driving unit drives the loading unit to move according to a driving signal; the first fixing unit fixes the loading unit, and the second fixing unit and the third fixing unit cooperate to fix a circular sample; the detection unit detects the force displacement of the sample to be tested; the sample to be tested comprises a plurality of punch balls; and the temperature control unit performs temperature adjustment control according to a control signal output by the control unit. The device can determine material mechanical property parameters based on a plurality of groups of data in a single experiment, has high reliability, can solve the problem of single test temperature of the existing clamp, can also realize the acquisition of mechanical property parameters of a plurality of materials at a specific temperature in a single experiment, avoids repeated experiments, and significantly improves experimental efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0046] The application will be further described below with reference to the drawings and embodiments. In the drawings:

[0047] FIG. 1 is a structural schematic view of the multifunctional small punch experimental device provided by the application;

[0048] FIG. 2 is a top view of the multifunctional small punch experimental device provided by the application;

[0049] Fig. 3 is an exploded view of the multifunctional small punch test device provided by the present application.

[0050] Fig. 4 is a flowchart of the multifunctional small punch test method provided by the present application. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0052] The present application provides a multifunctional small punch test device and method, which can realize accurate measurement of the mechanical properties of small punch test materials at room temperature, simultaneous testing of small punch tests of the same material at different temperatures, and simultaneous testing of small punch tests of different materials at the same temperature. Moreover, the multifunctional small punch test device and method provided by the present application have simple experimental steps and reasonable design. The multifunctional small punch test device can realize small punch tests of different diameters of punch balls and different sizes (diameters) of circular samples at a certain range under multiple temperature environments simultaneously. By combining multiple single small punch clamps, each corresponding pressure displacement sensor obtains a force displacement curve, and then the mechanical property parameters are obtained through a finite element inversion method. The implementation process is easy and has high precision, which provides a reference for the evaluation of the mechanical properties of the materials to be tested.

[0053] Referring to Figs. 1-3, the structure of the multifunctional small punch test device provided by the present application is shown.

[0054] Specifically, as shown in Fig. 1, the multifunctional small punch test device includes a driving unit, a loading unit, a first fixing unit 3, a second fixing unit 6, a third fixing unit, a detection unit, a temperature control unit, and a control unit. The driving unit and the control unit are not shown in Fig. 1.

[0055] In the embodiments of the present application, the driving unit is connected with the loading unit, and is used to drive the loading unit to move according to a driving signal.

[0056] Optionally, in the embodiments of the present application, the control unit is a computer terminal.

[0057] In the embodiment of the present application, the first fixing unit 3, the second fixing unit 6 and the third fixing unit are arranged from top to bottom along the axial direction, the first fixing unit 3 is used for fixing the loading unit, the second fixing unit 6 cooperates with the third fixing unit to fix the circular sample 10; the detection unit is installed on the loading unit and located between the first fixing unit 3 and the second fixing unit 6; the detection unit is used for detecting the force displacement of the sample to be pressed when the loading unit presses the sample to be pressed and outputting a detection signal to the control unit. The sample to be pressed includes a plurality of impact balls. The temperature control unit is connected with the control unit and is used for performing temperature adjustment control according to the control signal output by the control unit.

[0058] Specifically, as shown in FIG. 1, the loading unit includes a main loading rod 1 and a plurality of impact ball loading rods 2. The main loading rod 1 and the plurality of impact ball loading rods 2 are arranged on the first fixing unit 3, and the main loading rod 1 is connected with the driving unit; the main loading rod 1 moves under the driving of the driving unit and drives the plurality of impact ball loading rods 2 and the detection unit to move, so as to press the plurality of impact balls placed below the detection unit.

[0059] As shown in FIG. 2, the first fixing unit 3 includes a plurality of first threaded holes 31 arranged correspondingly to the plurality of impact ball loading rods 2; the detection unit includes a plurality of force displacement sensors 4 arranged correspondingly to the plurality of impact ball loading rods 2; the plurality of first threaded holes 31 are arranged uniformly at intervals along the circumference, and the first threaded hole 31 cooperates with the thread on the cylindrical surface of the impact ball loading rod 2; each force displacement sensor 4 is arranged below the corresponding impact ball loading rod 2.

[0060] Optionally, in the embodiment of the present application, the driving unit is a motor, and the electronic is a motor of an electronic universal testing machine. The connection mode of the main loading rod 1 and the motor can refer to the electronic universal testing machine. In a preferred embodiment, the plurality of impact ball loading rods 2 can be six. Correspondingly, the detection unit can include six force displacement sensors 4, and each force displacement sensor 4 is arranged below the corresponding impact ball loading rod 2.

[0061] In a preferred embodiment, as shown in FIG. 2, six first threaded holes 31 can be arranged on the first fixing unit 3, the six first threaded holes 31 are arranged uniformly at intervals of 60° along the circumference, the cylindrical surface of each impact ball loading rod 2 has a thread, and the thread on the cylindrical surface of the impact ball loading rod 2 cooperates with the corresponding first threaded hole 31. Each impact ball loading rod 2 is connected (generally through threaded connection) with a force displacement sensor 4 below, is responsible for detecting and collecting the force displacement curve of the impact ball in each group of small impact rod experiment, and the main loading rod 1 moves under the driving of the motor and drives the six impact ball loading rods 2 and the force displacement sensors 4 to move, so as to press the impact ball.

[0062] As shown in FIG. 3, in this embodiment, the second fixing unit 6 comprises: a plurality of through holes 61 corresponding to the plurality of ball loading rods 2; the plurality of through holes 61 are uniformly arranged at intervals along the circumference, and each through hole 61 is for the corresponding ball loading rod 2 and the ball to pass through. Wherein, the periphery of each through hole 61 is provided with a plurality of first positioning holes 62 and a plurality of second threaded holes 63; the third fixing unit comprises: a plurality of fixing devices; the plurality of fixing devices are correspondingly arranged with the plurality of through holes 61; each fixing device is a barrel structure 11, and the center of the cylinder of the barrel structure 11 is provided with a center hole 111, and the upper surface of the barrel structure 11 is provided with a plurality of second positioning holes 112 and a plurality of third threaded holes 113; the plurality of second positioning holes 112 are correspondingly arranged with the plurality of first positioning holes 62, and the plurality of third threaded holes 113 are correspondingly arranged with the plurality of second threaded holes 63; the plurality of second positioning holes 112 and the plurality of first positioning holes 62 are matched to pass through and fix the positioning pin 8; the plurality of second threaded holes 63 and the plurality of third threaded holes 113 are matched to pass through and connect the second fixing unit 6 and the third fixing unit to clamp the circular sample 10 located between the second fixing unit 6 and the third fixing unit.

[0063] Wherein, the center of the first threaded hole 31 on the first fixing unit 3, the through hole 61 on the second fixing unit 6 and the center hole 111 on the third fixing unit are located on the same axis.

[0064] In a preferred embodiment, the second fixing unit 6 can be provided with six through holes 61, which are uniformly arranged at intervals of 60° along the circumference, and the ball loading rod 2 and the ball can pass through the through hole 61. Around each through hole 61, there are also three first positioning holes 62 and three second threaded holes 63.

[0065] In this embodiment, the third fixing unit is a barrel structure 11. Correspondingly, the third fixing unit is provided with six barrel structures 11, and the center of the cylinder of each barrel structure 11 is provided with a center hole 111. The upper surface of the barrel structure 11 is provided with a third threaded hole 113 and a second positioning hole 112. The positioning pin 8 passes through the first positioning hole 62 on the second fixing unit 6 and the second positioning hole 112 on the third fixing unit to realize the positioning and matching of the second fixing unit 6 and the third fixing unit. The connecting screw 9 passes through the second threaded hole 63 of the second fixing unit 6 and the third threaded hole 113 of the third fixing unit to realize the overall connection of the second fixing unit 6 and the third fixing unit, thereby realizing the clamping of the circular sample 10. Wherein, the upper surface of the circular sample 10 is attached to the bottom surface of the second fixing unit 6, and the lower surface of the circular sample 10 is attached to the upper surface of the third fixing unit.

[0066] Optionally, in the embodiment of the present application, the diameter of the ball is 0-20mm, the diameter of the circular sample is 0-40mm, and the center of the ball and the center of the circular sample are on the same vertical axis. The centers of the six first threaded holes 31 on the first fixing unit 3, the six through holes 61 on the second fixing unit 6, and the central hole 111 on the third fixing unit are on the same vertical axis.

[0067] Optionally, in the embodiment of the present application, the temperature control unit comprises a plurality of temperature control modules corresponding to the plurality of ball loading rods 2, respectively used for temperature adjustment. In a preferred embodiment, the temperature control unit can be provided with six temperature control modules.

[0068] Optionally, in the embodiment of the present application, each temperature control module comprises a temperature control box 7, an electric heating wire 71, and a temperature sensor 72.

[0069] The temperature control box 7 is arranged below the corresponding fixing device, and the electric heating wire 71 and the temperature sensor 72 are arranged inside the temperature control box 7; the electric heating wire 71 is connected with the control unit and is used for on / off control according to the control of the control unit; the temperature sensor 72 is used for detecting the temperature inside the temperature control box 7 and outputting a temperature detection signal to the control unit.

[0070] Further, each temperature control module further comprises a cooling liquid delivery hole 73 arranged on the temperature control box and used for delivering cooling liquid into the temperature control box 7.

[0071] Referring to FIG. 4, FIG. 4 is a flowchart of the multifunctional small ball punch experimental method provided by the present application.

[0072] The multifunctional small ball punch experimental method is applied to the multifunctional small ball punch experimental device disclosed in the embodiment of the present application.

[0073] Specifically, as shown in FIG. 4, the multifunctional small ball punch experimental method comprises the following steps:

[0074] Step S101: constructing a small ball punch experimental model.

[0075] Optionally, in the embodiment of the present application, the small ball punch experimental model can be a hollomon model. For metal materials, the yield stress is 200-800Mpa, and the hardening index is 0.1-0.5.

[0076] Step S102: obtaining input parameters and experimental load.

[0077] The input parameters are input material mechanical property parameters. The experimental load can be determined according to actual simulation.

[0078] Step S103: based on the input parameters and the load of the test, simulation calculation is performed to obtain a plurality of groups of simulated force-displacement curves.

[0079] Step S201: a small punch test is performed.

[0080] Step S202: test data is recorded during the test.

[0081] Step S203: analysis is performed according to the test data to obtain a plurality of groups of test force-displacement curves.

[0082] Step S301: it is judged whether the simulated force-displacement curve matches the plurality of groups of test force-displacement curves; if not, the input parameters are adjusted and the simulation calculation is continued until the simulated force-displacement curve matches the plurality of groups of test force-displacement curves.

[0083] Step S302: if matched, the material mechanical property parameters are determined.

[0084] In the embodiment of the application, when the simulated load displacement curve (i.e. the simulated force-displacement curve) matches the test load displacement curve (i.e. the test force-displacement curve), it is considered that the input combination is the mechanical property parameter of the test material. Wherein, 20 points are selected on the test force-displacement curve and the simulated force-displacement curve, and the error of the 20 points is not more than ±5%, which can be determined as matching, i.e. consistent.

[0085] For the first problem of the prior art, the multifunctional small punch test device and method provided by the application adopts six groups of different size punch balls (the diameters are 1mm, 2mm, 3mm, 4mm, 5mm and 6mm), loading rods and matching load sensors, which can realize the simultaneous acquisition of 6 groups of different small punch test curves; then through the comparison of the 6 groups of small punch test curves calculated by the input mechanical property parameters in the finite element model, when the 6 groups of load displacement curves calculated by the input mechanical property parameters in the finite element model match the 6 groups of load displacement curves in the test, it can be considered that the input mechanical property parameters in the finite element software are the mechanical property parameters of the material to be tested.

[0086] For the second problem of the prior art, the application can solve the problem that the existing clamp test temperature is single and only one temperature condition can be tested in a single experiment by setting six groups of environmental boxes (i.e. temperature control boxes 7) at the test position of the rotating small punch sample, and setting electric heating wires 71 (to raise the environmental temperature to 400℃), liquid nitrogen interfaces (i.e. cooling liquid delivery holes 73, to lower the temperature to-196℃) and temperature sensors 72 (environmental temperature feedback) in the environmental boxes.

[0087] In view of the prior art problem 3, the application can obtain the mechanical property parameters of 6 kinds of materials at a specific temperature by a single experiment when the mechanical property parameters of 2-6 kinds of materials at a specific temperature (-196℃-400℃) need to be tested simultaneously, only by adjusting the temperature of 6 groups of environmental boxes to be uniform, then performing small punch rod tests of 6 kinds of different materials by selecting 6 kinds of different materials, and referring to the above method to perform finite element inversion respectively.

[0088] The application has simple steps and reasonable design, and can simultaneously perform small punch rod tests of the same or different materials within a certain range at a specific temperature (-196℃-400℃) by using the application. The small punch rod tests at multiple temperature environments can be simultaneously performed by using the environmental boxes. The load curve is obtained by corresponding each force displacement sensor 4, the displacement curve of the clamp in the application is combined, and the mechanical property parameters are obtained by the finite element inversion method. The implementation process is relatively easy, has high precision, further improves the experimental efficiency, and provides a basis for the implementation of the small punch rod test at a variable temperature environment and the accurate test of the mechanical property of the material.

[0089] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the embodiments can be referred to each other.

[0090] The skilled person can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in the present text can be realized by electronic hardware, computer software or a combination of both. In order to clearly show the interchangeability of hardware and software, the components and steps of each example have been described in the above description. Whether the functions are realized by hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0091] The steps of the method or algorithm described in combination with the embodiments disclosed in the present text can be directly implemented by hardware, software modules executed by a processor, or a combination of both. The software modules can be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0092] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it accordingly, and cannot limit the protection scope of the present application. Any equivalent changes and modifications made within the scope of the claims of the present application shall belong to the scope of the claims of the present application.

Claims

1. A multi-functional small punch specimen testing device, characterized by, The application relates to a testing device for a circular sample, which comprises a driving unit, a loading unit, a first fixing unit, a second fixing unit, a third fixing unit, a detecting unit, a temperature control unit and a control unit. The driving unit is connected with the loading unit and is used for driving the loading unit to move according to a driving signal. The first fixing unit, the second fixing unit and the third fixing unit are arranged along an axial direction from top to bottom, the first fixing unit is used for fixing the loading unit, the second fixing unit and the third fixing unit are used for fixing a circular sample, the detecting unit is installed on the loading unit and is located between the first fixing unit and the second fixing unit, the detecting unit is used for detecting the force displacement of a sample to be pressed when the loading unit presses the sample to be pressed and outputs a detecting signal to the control unit. The sample to be pressed comprises a plurality of impact balls. The temperature control unit is connected with the control unit and is used for executing temperature adjusting control according to a control signal output by the control unit. The loading unit comprises a main loading rod and a plurality of impact ball loading rods.

2. The multi-functional small punch specimen testing device of claim 1, wherein, The main loading rod and the plurality of impact ball loading rods are arranged on the first fixing unit, and the main loading rod is connected with the driving unit. The main loading rod moves according to the driving of the driving unit and drives the plurality of impact ball loading rods and the detecting unit to move, so as to press a plurality of impact balls placed below the detecting unit. The first fixing unit comprises a plurality of first threaded holes corresponding to the plurality of impact ball loading rods, and the detecting unit comprises a plurality of force displacement sensors corresponding to the plurality of impact ball loading rods.

3. The multi-functional small punch specimen testing device of claim 2, wherein, The plurality of first threaded holes are arranged uniformly along a circumferential direction, and the first threaded holes are matched with threads on the cylindrical surface of the impact ball loading rods. Each force displacement sensor is arranged below a corresponding impact ball loading rod. The second fixing unit comprises a plurality of through holes corresponding to the plurality of impact ball loading rods.

4. The multi-functional small punch specimen testing device of claim 2, wherein, The plurality of through holes are arranged uniformly along a circumferential direction, and each through hole is used for allowing a corresponding impact ball loading rod and an impact ball to pass through. A plurality of first positioning holes and a plurality of second threaded holes are arranged around each through hole.

5. The multi-functional small punch specimen testing device of claim 4, wherein, The third fixing unit comprises a plurality of fixing devices, and the plurality of fixing devices are arranged corresponding to the plurality of through holes. Each fixing device is in a barrel structure, a center hole is arranged at the center of the cylindrical surface of the barrel structure, and a plurality of second positioning holes and a plurality of third threaded holes are arranged on the upper surface of the barrel structure. The plurality of second positioning holes are arranged corresponding to the plurality of first positioning holes, and the plurality of third threaded holes are arranged corresponding to the plurality of second threaded holes. The plurality of second positioning holes and the plurality of first positioning holes are matched to allow a positioning pin to pass through and be fixed. The plurality of second threaded holes and the plurality of third threaded holes are matched to allow a connecting screw to pass through and connect the second fixing unit and the third fixing unit, so as to clamp the circular sample located between the second fixing unit and the third fixing unit. The temperature control unit comprises a plurality of temperature control modules.

6. The multi-functional small punch specimen testing device of claim 5, wherein, ​ The plurality of temperature control modules are arranged correspondingly to the plurality of ball loading rods, and are respectively used for temperature adjustment.

7. The multi-functional small punch specimen testing device of claim 6, wherein, Each of the temperature control modules comprises a temperature control box, an electric heating wire and a temperature sensor. The temperature control box is arranged below the corresponding fixing device, and the electric heating wire and the temperature sensor are arranged inside the temperature control box. The electric heating wire is connected to the control unit, and is used for on / off control according to the control of the control unit. The temperature sensor is used for detecting the temperature inside the temperature control box and outputting a temperature detection signal to the control unit.

8. The multi-functional small punch specimen testing device of claim 7, wherein, Each of the temperature control modules further comprises a cooling liquid delivery hole. The cooling liquid delivery hole is arranged on the temperature control box, and is used for delivering cooling liquid to the inside of the temperature control box.

9. The multi-functional small punch specimen testing device of claim 5, wherein, The center of the first threaded hole on the first fixing unit, the center of the through hole on the second fixing unit and the center of the center hole on the third fixing unit are located on the same axis.

10. A multi-functional small punch testing method applied to the multi-functional small punch testing device of any one of claims 1-9, characterized in that, The method comprises the following steps: constructing a small punch rod experiment model; obtaining input parameters and test loads; performing simulation calculation based on the input parameters and the test loads to obtain a plurality of simulated force-displacement curves; performing a small punch rod test; recording test data during the test; analyzing the test data to obtain a plurality of test force-displacement curves; determining whether the simulated force-displacement curves match the plurality of test force-displacement curves; if matched, determining material mechanical property parameters; if not matched, adjusting the input parameters and continuing the simulation calculation until the simulated force-displacement curves match the plurality of test force-displacement curves.

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