Low-speed energy consumption testing method and device for evaluating impact resistance of thermoplastic resin

Abstract

The invention provides a low-speed energy consumption testing method and device for evaluating the impact resistance of thermoplastic resin. The low-speed energy consumption testing method comprises the following steps: S1, synchronously measuring strain, stress and temperature of a test sample in a mechanical low-speed loading process; s2, post-processing the temperature drop part in the measured temperature, subtracting the temperature drop starting time from the measurement time, and subtracting the long-term temperature of the temperature drop from the measurement temperature so as to obtain a temperature drop-time result; s3, parametric fitting is carried out, so that fitting of the initial time, the end time and the long-term temperature of the temperature drop process is intact, and a coefficient x is determined; s4, calculating adiabatic temperature rise in the plastic deformation process by using the determined coefficient x and the time step length of real-time temperature measurement; s5, calculating slow energy consumption according to the relative temperature difference between the adiabatic temperature rise and the initial temperature by using the specific heat capacity of the material at the initial temperature; and S6, obtaining stress-strain-adiabatic temperature rise-energy consumption data, and synchronously and accurately measuring stress, strain and energy consumption.

Description

Technical Field

[0001] The invention belongs to the technical field of testing for evaluating the impact resistance of thermoplastic resins, and in particular relates to a slow energy consumption testing method and device for evaluating the impact resistance of thermoplastic resins. Background Art

[0002] Thermoplastic resins such as polycarbonate (PC) have excellent impact resistance. They are often subjected to large deformation and damage in engineering applications such as aircraft canopies, fully transparent mobile phones, and high-pressure medical syringes. Understanding the impact resistance of materials is an important part of conducting strength analysis of engineering structures and achieving reliability design. Due to the heat exchange between the measurement environment and the test sample, rapid loading experiments are usually carried out to directly measure the dissipated heat and stress response. However, high strain rate experimental characterization is relatively difficult, expensive, and has a single loading method. Moreover, for materials under complex loading conditions such as cyclic loading (slow speed), only partial stress behavior can be measured. There is a lack of characterization results of thermal response, which makes it impossible to provide comprehensive characterization data for the evaluation of the impact resistance of materials. Therefore, it is urgent to develop a method that can accurately measure the plastic dissipation energy of impact-resistant materials under slow loading. Summary of the invention

[0003] In view of the above technical problems, the present invention provides a slow energy consumption test method and device for evaluating the impact resistance of thermoplastic resins. The method is a method for measuring the dissipated energy and representative stress-strain of thermoplastic polymers during slow plastic deformation. The mechanical properties testing equipment, infrared thermal imager and optical strain measurement device are integrated together to enable synchronous and accurate measurement of stress, strain and energy consumption.

[0004] Note that the description of these objectives does not prevent the existence of other objectives. One embodiment of the present invention does not need to achieve all of the above objectives. Objectives other than the above objectives can be extracted from the description of the specification, drawings, and claims.

[0005] The present invention achieves the above technical objectives through the following technical means.

[0006] A slow energy consumption test method for evaluating the impact resistance of a thermoplastic resin comprises the following steps:

[0007] Step S1, synchronously measuring the strain, stress and temperature of the test sample during the mechanical slow loading process; the temperature is measured by an infrared thermal imager; the strain is measured by an optical strain measuring device; the stress is measured by a mechanical property testing device to obtain the torque, which is calculated according to Formula 1;

[0008]

[0009] Where, τ is stress; M is the actual measured torque, d is the average value of the inner and outer diameters of the thin wall of the test sample, and δ is the thin wall thickness of the test sample;

[0010] Step S2: post-process the temperature drop portion of the temperature measured in step S1, subtract the temperature drop start time t1 from the measured time, and subtract the long-term temperature T of the temperature drop from the measured temperature. ∞ , thus obtaining the temperature drop-time result;

[0011] Step S3: According to the temperature drop-time result obtained in step S2, equation 2 is used for parameter fitting to convert the initial time t1 to the end time t2 of the temperature drop process and the long-term temperature T ∞ The fit is perfect, so the coefficient χ in equation 2 is determined:

[0012]

[0013] Where T is the actual measured temperature, T A is the starting temperature of temperature drop, χ is the equivalent coefficient of convection model, and t is the actual measurement time;

[0014] Step S4, according to the entire real-time measured temperature, using the coefficient χ determined in step S3 and the time step Δt of the real-time temperature measurement, the adiabatic temperature rise during the plastic deformation process is calculated using the summation equation 3, that is, the adiabatic temperature:

[0015]

[0016] Among them, T 绝热 is the adiabatic temperature, T t0 is the temperature at time t0, i.e., the starting temperature of the actual measurement, T is the actual measurement time, T ti is the time t i Temperature at time, t i To represent each measurement moment i;

[0017] Step S5, using the specific heat capacity c of the material at the starting temperature p According to the relative temperature difference between the adiabatic temperature rise and the starting temperature obtained in step S4, the slow energy consumption Δξ is calculated using formula 4. t :

[0018]

[0019] Step S6, obtaining stress-strain-adiabatic temperature rise-energy consumption data to complete thermodynamic measurement.

[0020] In the above scheme, the material of the test sample is polycarbonate (PC), the test sample is a ring, the wall thickness is 1mm, the width is 2mm, the small fillets on both sides are R1mm, the inner diameter of the thin wall is 18mm, the outer diameter of the end face flange is 30mm, the sample thickness of the entire test sample is 12mm, and the processing error of all dimensions is ±0.1mm.

[0021] In the above scheme, the strain rate of slow loading is 0.001-0.1s -1 .

[0022] In the above scheme, the duration from the initial time t1 to the end time t2 of the temperature drop is 8-12 seconds.

[0023] In the above scheme, the long-term temperature of the temperature drop is T ∞ The time difference between the current time t3 and the initial time t1 of the temperature drop is 300-400 seconds.

[0024] A device for implementing the slow energy consumption test method for evaluating the impact resistance of thermoplastic resin, comprising an infrared thermal imager, a mechanical property testing device, an optical strain measuring device and a control system, wherein the infrared thermal imager, the mechanical property testing device and the optical strain measuring device are respectively connected to the control system;

[0025] The mechanical property testing equipment clamps the test sample, and the infrared thermal imager and the optical strain measuring device are placed on both sides or the same side of the test sample;

[0026] The infrared thermal imager is used to measure the temperature of the test sample during the mechanical slow loading process; the optical strain measurement device is used to measure the strain of the test sample during the mechanical slow loading process; and the mechanical property testing equipment is used to measure the torque of the test sample during the mechanical slow loading process.

[0027] In the above scheme, the mechanical properties testing equipment includes a rotating shaft, a fixture and a torque sensor;

[0028] The test sample is clamped in the middle of the fixture, one side of the fixture is connected to the rotating shaft, and the other side is provided with a torque sensor, which is connected to the control system; the rotation of the rotating shaft causes one side of the fixture to drive the test sample to twist, thereby generating strain, and the torque sensor is used to detect the applied torque of the test sample and transmit it to the control system.

[0029] In the above solution, the test sample is a thin-walled ring, and the flanges at both ends of the test sample are bonded to the fixture.

[0030] In the above scheme, the optical strain measurement device includes two CCD cameras and a light source, and the CCD cameras are connected to a control system; the CCD cameras are used to take torsional strain images of the test sample.

[0031] In the above solution, the infrared thermal imager, mechanical property testing equipment, and optical strain measuring device are connected to the control system via a synchronous trigger.

[0032] Principle of the invention:

[0033] During the slow deformation of thermoplastic resin, the heat exchange (convection and heat conduction) between the test sample and the surrounding environment will gradually cool down the temperature rise caused by plastic dissipation energy. The equivalent heat loss can be quantitatively described by a simple heat convection formula, and the equation is: Integrating the equation gives

[0034]

[0035] in

[0036] ρ is the mass density of the test sample, w is the width of the test sample, and h is the thermal convection coefficient;

[0037] After the mechanical loading is completed, the material has no plastic energy consumption, and only heat exchange exists, so the temperature drop at the current stage can be used to determine the coefficient χ in the heat convection equation;

[0038] Through integral operation, equation 2 is obtained, and parameter fitting is performed to convert the initial time t1 to the end time t2 of the temperature drop process and the long-term temperature T ∞ The fit is perfect, so the coefficient χ in equation 2 is determined:

[0039]

[0040] The optimal coefficient of the thermal convection equation can be obtained by using the data of the early stage of temperature drop. The principle is that compared with heat conduction, heat convection transfers heat faster. The early stage of temperature drop is mainly dominated by heat convection, while the later stage is a mixed mode of heat convection and heat conduction.

[0041] In addition, the thermal conductivity of the resin is poor, and the loss of plastic dissipated energy caused by heat conduction accounts for a relatively small proportion; finally, based on the real-time temperature measurement during the loading process and the heat convection equation determined above, according to the formula To calculate the adiabatic temperature rise during plastic deformation, considering the actual measurement results and the convenience of related calculations, the summation integral equation is transformed into the summation formula

[0042]

[0043] Finally, according to the relative temperature difference between the adiabatic temperature rise and the starting temperature, the formula is used Calculate the plastic energy.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. The present invention can make up for the single loading mode of high-speed impact performance test, reduce the test cost, and expand the test method for evaluating the impact resistance of materials;

[0046] 2. The present invention determines the key coefficient of the heat convection equation by using the temperature drop after the external load ends, and can quantitatively characterize the energy dissipation of the slow deformation process of the sample;

[0047] 3. The present invention uses the early temperature drop data of the temperature drop process to obtain an ideal key coefficient, thereby improving the accuracy of the slow energy consumption test of the material;

[0048] 4. The present invention can realize the simultaneous measurement of the plastic dissipation energy (or adiabatic temperature rise) and stress-strain of thermoplastic polymers, thereby understanding the thermodynamic mechanism of thermoplastic resins and providing characterization data for the evaluation of the impact resistance of such materials, so as to accurately evaluate the dynamic impact response of actual engineering structures, i.e., impact energy absorption and dissipation.

[0049] Note that the description of these effects does not prevent the existence of other effects. One embodiment of the present invention does not necessarily have all of the above effects. Effects other than the above can be clearly seen and extracted from the description of the specification, drawings, claims, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a structural schematic diagram of a slow energy consumption testing device for evaluating the impact resistance of a thermoplastic resin according to one embodiment of the present invention;

[0051] Figure 2 is a schematic diagram of strain measurement according to an embodiment of the present invention;

[0052] Figure 3 is a schematic diagram of stress measurement according to an embodiment of the present invention;

[0053] Figure 4 is a schematic diagram of temperature measurement according to an embodiment of the present invention;

[0054] Figure 5 is a schematic diagram of post-processing of a temperature drop curve according to an embodiment of the present invention;

[0055] Figure 6 is a schematic diagram of determining thermal convection model coefficients using a parameterized fitting method according to an embodiment of the present invention;

[0056] Figure 7 is a schematic diagram of calculating adiabatic temperature rise using a thermal convection model based on actual temperature measurement according to an embodiment of the present invention;

[0057] Figure 8is a schematic diagram of determining plastic dissipated energy according to adiabatic temperature rise according to an embodiment of the present invention;

[0058] Fig. 9 is the measurement of real-time stress-strain-temperature under unidirectional torsion in Example 1 of the present invention, wherein Fig. 9 (a) is the torsional shear stress curve under unidirectional torsion, Fig. 9 (b) is the shear strain curve under unidirectional torsion. Fig. 9 (c) is the temperature curve under unidirectional torsion. Fig. 9 (d) is the temperature difference curve under unidirectional torsion;

[0059] Fig.10 is the characterization result of adiabatic temperature rise and plastic dissipated energy under unidirectional torsion in Example 1 of the present invention, wherein Fig.10 (a) is the adiabatic temperature rise curve under unidirectional torsion. Fig.10 (b) is the curve of plastic dissipation energy under unidirectional torsion;

[0060] Fig.11 is the real-time stress-strain-temperature measurement under reverse cyclic torsion in Example 2 of the present invention, wherein Fig.11 (a) is the torsional shear stress curve under reverse cyclic torsion. Fig.11 (b) is the shear strain curve under reverse cyclic torsion. Fig.11 (c) is the temperature curve under reverse cycle torsion. Fig.11 (d) is the temperature difference curve under reverse cycle torsion;

[0061] Fig.12 is the characterization result of adiabatic temperature rise and plastic dissipated energy under reverse cyclic torsion in Example 2 of the present invention, wherein Fig.12 (a) is the adiabatic temperature rise curve under reverse cycle torsion. Fig.12 (b) is the plastic dissipation energy curve under reverse cyclic torsion.

[0062] In the figure, 1 is an infrared thermal imager, 2 is a test sample, 3 is a mechanical property testing device, 31 is a rotating axis, 32 is a fixture, 33 is a torque sensor, 4 is an optical strain measuring device, 41 is a light source, 5 is a control system, 51 is a synchronous trigger, 6 is a strain-time measurement curve, 7 is a stress-time measurement curve, 8 is a real-time temperature-time measurement curve, 81 is a temperature drop curve, 82 is a t1 to t2 and a long-term temperature curve, 83 is adiabatic temperature rise curve, and 84 is a plastic dissipated energy curve. DETAILED DESCRIPTION

[0063] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0064] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "front", "back", "left", "right", "up", "down", "axial", "radial", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0065] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0066] In order to describe the implementation details of the present invention in detail, the slow energy consumption test method for evaluating the impact resistance of thermoplastic resin of the present invention is described below with reference to the accompanying drawings.

[0067] A device for implementing the slow energy consumption test method for evaluating the impact resistance of thermoplastic resin, comprising an infrared thermal imager 1, a mechanical property testing device 3, an optical strain measuring device 4 and a control system 5, wherein the infrared thermal imager 1, the mechanical property testing device 3 and the optical strain measuring device 4 are respectively connected to the control system 5;

[0068] The mechanical property testing device 3 clamps the test sample 2, and the infrared thermal imager 1 and the optical strain measuring device 4 are placed on both sides or the same side of the test sample 2;

[0069] The infrared thermal imager 1 is used to measure the temperature of the test sample 2 during the mechanical slow loading process; the optical strain measurement device 4 is used to measure the strain of the test sample 2 during the mechanical slow loading process; the mechanical property testing equipment 3 is used to measure the torque of the test sample 2 during the mechanical slow loading process.

[0070] The mechanical property testing equipment 3 includes a rotating shaft 31, a fixture 32 and a torque sensor 33; the middle of the fixture 32 clamps the test sample 2, one side of the fixture is connected to the rotating shaft 31, and the other side is provided with a torque sensor 33, and the torque sensor 33 is connected to the control system 5; the rotation of the rotating shaft 31 causes one side of the fixture to drive the test sample 2 to twist, thereby generating strain, and the torque sensor 33 is used to detect the applied torque of the test sample 2 and transmit it to the control system 5.

[0071] The test sample 2 is a thin-walled ring, and the flanges at both ends of the test sample 2 are bonded to the fixture 32 by high-strength glue.

[0072] The optical strain measuring device 4 includes two CCD cameras and a light source 41 . The CCD cameras are connected to a control system 5 . The CCD cameras are used to take torsional strain images of the test sample 2 .

[0073] The infrared thermal imager 1 , the mechanical property testing equipment 3 , and the optical strain measuring device 4 are connected to the control system 5 via a synchronous trigger 51 .

[0074] A slow energy consumption test method for evaluating the impact resistance of a thermoplastic resin comprises the following steps:

[0075] Step S1, synchronously measuring the strain, stress and temperature of the test sample 2 during the mechanical slow loading process; the temperature is measured by the infrared thermal imager 1; the strain is measured by the optical strain measuring device 4; the stress is measured by the mechanical property testing equipment 3 and the torque is calculated according to formula 1;

[0076]

[0077] Wherein, τ is stress; M is the actual measured torque, d is the average value of the inner and outer diameters of the thin wall of the test sample 2, and δ is the thin wall thickness of the test sample 2;

[0078] Step S2: post-process the temperature drop portion of the temperature measured in step S1, subtract the temperature drop start time t1 from the measured time, and subtract the long-term temperature T of the temperature drop from the measured temperature. ∞ , thus obtaining the temperature drop-time result;

[0079] Step S3: According to the temperature drop-time result obtained in step S2, equation 2 is used for parameter fitting to convert the initial time t1 to the end time t2 of the temperature drop process and the long-term temperature T ∞The fit is perfect, so the coefficient χ in equation 2 is determined:

[0080]

[0081] Where T is the actual measured temperature, T A is the starting temperature of temperature drop, χ is the equivalent coefficient of convection model, and t is the actual measurement time;

[0082] Step S4, according to the entire real-time measured temperature, using the coefficient χ determined in step S3 and the time step Δt of the real-time temperature measurement, the adiabatic temperature rise during the plastic deformation process is calculated using the summation equation 3, that is, the adiabatic temperature:

[0083]

[0084] Among them, T 绝热 is the adiabatic temperature, T t0 is the temperature at time t0, i.e. the starting temperature of the actual measurement, T is the actual measurement time, is the time t i Temperature at time, t i To represent each measurement moment i;

[0085] Step S5, using the specific heat capacity c of the material at the starting temperature p According to the relative temperature difference between the adiabatic temperature rise and the starting temperature obtained in step S4, the slow energy consumption Δξ is calculated using formula 4. t :

[0086]

[0087] Step S6, obtaining stress-strain-adiabatic temperature rise-energy consumption data to complete thermodynamic measurement.

[0088] In a specific embodiment of the present invention, the material of the test sample 2 is polycarbonate PC, the test sample 2 is a circular ring with a wall thickness of 1 mm, a width of 2 mm, a small fillet R of 1 mm on both sides, an inner diameter of the thin wall of 18 mm, an outer diameter of the end face flange of 30 mm, a sample thickness of 12 mm, and a processing error of all dimensions of ±0.1 mm.

[0089] The strain rate of the slow loading is 0.001-0.1s -1 .

[0090] The duration from the initial time t1 to the end time t2 of the temperature drop is 8-12 seconds, which can obtain the best equivalent coefficient χ.

[0091] The long-term temperature T of the temperature drop ∞The time difference between the time t3 and the initial time t1 of the temperature drop is 300-400 seconds, which is used to obtain the best long-term temperature T ∞ .

[0092] Implementation Example 1:

[0093] In this embodiment, the test sample is polycarbonate PC, and the specific heat capacity of the test sample 2 is 1.2 J / gK; Fig. 9 As shown, the loading method is unidirectional torsion, and the stress test curve 90, the shear strain test curve 91 and the real-time temperature test curve 92 are measured simultaneously; the design strain rate is 0.01s -1 The actual measured strain rate is 0.006s -1 ; The maximum loading strain is about 70%; After loading, an unloading stage is applied, unloading to 60% of the yield stress, that is, the time difference between t1 and t2 is 12 seconds; The time difference between the long-term temperature of the temperature drop and the initial time of the temperature drop is 350 seconds; The temperature drop data test curve 93 is used to determine the equivalent coefficient χ. If the entire temperature drop curve is used, the coefficient 94 will be obtained: χ=0.023; Only the early temperature drop t1 to t2 and the long-term temperature T ∞ =19.22℃ will get the optimal coefficient 95:χ=0.03; Fig.10 The adiabatic temperature rise and plastic energy dissipation of the unidirectional slow torsion process are shown respectively. It can be seen from the figure that during the slow loading to 70% strain, compared with the real-time temperature measurement curve 98, the adiabatic temperature rise curve 96 obtained by using the optimal coefficient χ=0.03 is higher than the adiabatic temperature rise curve 97 obtained by using the conventional method χ=0.023. Correspondingly, from the obtained plastic energy dissipation curve 99 and the plastic energy dissipation curve 100 obtained by the conventional method, it can be seen that the obtained plastic energy dissipation of 9.2 J / g is more accurate than the plastic energy dissipation of 7.4 J / g obtained by the conventional method.

[0094] Implementation Example 2:

[0095] In this embodiment, the test sample is polycarbonate PC, such as Fig.11 As shown, the loading method is forward-reverse cyclic torsion, and the stress test curve 110, the shear strain test curve 111 and the real-time temperature test curve 112 are measured simultaneously; the design strain rate is 0.1s -1 The actual measured strain rate is 0.01s -1; The strain range of cyclic loading is -51% to 43%; The number of loading cycles is 3.25; After the loading is completed, the sample is kept still, and the time difference between t1 and t2 is 8 seconds; The time difference between the long-term temperature of the temperature drop and the initial time of the temperature drop is 300 seconds; The temperature drop data curve 115 is used to determine the equivalent coefficient χ. If the entire temperature drop curve is used, the coefficient 113 will be obtained: χ=0.041; Only the early temperature drop t1 to t2 and the long-term temperature T ∞ =19.6℃ will get the optimal coefficient 114:χ=0.055; from Fig.12 It can be seen that during the 3.25-cycle loading process, compared with the real-time temperature measurement curve 118, the adiabatic temperature rise curve 116 obtained by using the optimal coefficient χ=0.055 is higher than the adiabatic temperature rise curve 117 obtained by using the conventional method χ=0.041. Correspondingly, from the obtained plastic energy dissipation curve 119 and the plastic energy dissipation curve 120 obtained by the conventional method, it can be seen that the accurate plastic energy dissipation is 49.4 J / g, while the plastic energy dissipation obtained by the conventional method is only 37.4 J / g.

[0096] The present invention uses the temperature drop after loading to calibrate the coefficient of the simple thermal convection formula, so as to quantitatively characterize the loss of plastic heat dissipation caused by heat exchange during loading; based on the thermal convection formula and combined with the entire real-time temperature measurement, the adiabatic temperature rise and plastic energy consumption of the resin in the slow deformation process are calculated, and finally the slow energy consumption of the test sample and the related thermodynamic behavior, that is, the stress-strain-adiabatic temperature rise-energy consumption data are obtained. The present invention can reduce the testing cost of the characterization data required for the thermodynamic research of impact-resistant polymer materials, break through the singleness of the loading method in the high-rate thermodynamic test, and help to comprehensively evaluate the impact resistance of actual engineering structural materials. The present invention can be used to synchronously measure the stress-strain-adiabatic temperature rise of the test sample.

[0097] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0098] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A slow energy consumption test method for evaluating the impact resistance of thermoplastic resins, characterized in that: The following steps are involved: Step S1, synchronously measuring the strain, stress and temperature of the test sample (2) during the mechanical slow loading process; the temperature is measured by the infrared thermal imager (1); the strain is measured by the optical strain measuring device (4); the stress is measured by the mechanical property testing equipment (3) and the torque is calculated according to formula 1; Wherein, τ is stress; M is the actual measured torque, d is the average value of the inner and outer diameters of the thin wall of the test sample (2), and δ is the thin wall thickness of the test sample (2); Step S2: post-process the temperature drop portion of the temperature measured in step S1, subtract the temperature drop start time t1 from the measured time, and subtract the long-term temperature T of the temperature drop from the measured temperature. ∞ , thus obtaining the temperature drop-time result; Step S3: According to the temperature drop-time result obtained in step S2, equation 2 is used for parameter fitting to convert the initial time t1 to the end time t2 of the temperature drop process and the long-term temperature T ∞ The fit is perfect, so the coefficient χ in equation 2 is determined: Where T is the actual measured temperature, T A is the starting temperature of temperature drop, χ is the equivalent coefficient of convection model, and t is the actual measurement time; Step S4, according to the entire real-time measured temperature, using the coefficient χ determined in step S3 and the time step Δt of the real-time temperature measurement, the adiabatic temperature rise during the plastic deformation process is calculated using the summation equation 3, that is, the adiabatic temperature: Among them, T 绝热 is the adiabatic temperature, is the temperature at time t0, i.e. the starting temperature of the actual measurement, T is the actual measurement time, is the time t i Temperature at time, t i To represent each measurement moment i; Step S5, using the specific heat capacity c of the material at the starting temperature p According to the relative temperature difference between the adiabatic temperature rise and the starting temperature obtained in step S4, the slow energy consumption Δξ is calculated using formula 4. t : Step S6, obtaining stress-strain-adiabatic temperature rise-energy consumption data to complete thermodynamic measurement.

2. The slow energy consumption test method for evaluating the impact resistance of thermoplastic resin according to claim 1, characterized in that: The material of the test sample (2) is polycarbonate (PC). The test sample (2) is a circular ring with a wall thickness of 1 mm, a width of 2 mm, small fillets on both sides of R1 mm, a thin wall inner diameter of 18 mm, an outer diameter of the end face flange of 30 mm, a sample thickness of 12 mm, and a processing error of all dimensions of ±0.1 mm.

3. The slow energy consumption test method for evaluating the impact resistance of thermoplastic resin according to claim 1, characterized in that: The strain rate of slow loading is 0.001-0.1s -1 .

4. The slow energy consumption test method for evaluating the impact resistance of thermoplastic resin according to claim 1, characterized in that: The duration from the initial time t1 to the end time t2 of the temperature drop is 8-12 seconds.

5. The slow energy consumption test method for evaluating the impact resistance of thermoplastic resin according to claim 1, characterized in that: The long-term temperature T of the temperature drop ∞ The time difference between the current time t3 and the initial time t1 of the temperature drop is 300-400 seconds.

6. A device for implementing the slow energy consumption test method for evaluating the impact resistance of thermoplastic resins according to any one of claims 1 to 5, characterized in that: It comprises an infrared thermal imager (1), a mechanical properties testing device (3), an optical strain measuring device (4) and a control system (5), wherein the infrared thermal imager (1), the mechanical properties testing device (3) and the optical strain measuring device (4) are respectively connected to the control system (5); The mechanical property testing device (3) clamps the test sample (2), and the infrared thermal imager (1) and the optical strain measuring device (4) are placed on both sides or on the same side of the test sample (2); The infrared thermal imager (1) is used to measure the temperature of the test sample (2) during the mechanical slow loading process; the optical strain measurement device (4) is used to measure the strain of the test sample (2) during the mechanical slow loading process; and the mechanical property testing equipment (3) is used to measure the torque of the test sample (2) during the mechanical slow loading process.

7. The device for the slow energy consumption test method for evaluating the impact resistance of thermoplastic resin according to claim 6, characterized in that: The mechanical property testing device (3) comprises a rotating shaft (31), a fixture (32) and a torque sensor (33); The middle of the clamp (32) clamps the test sample (2), one side of the clamp is connected to the rotating shaft (31), and the other side is provided with a torque sensor (33), and the torque sensor (33) is connected to the control system (5); the rotation of the rotating shaft (31) causes one side of the clamp to drive the test sample (2) to twist, thereby generating strain, and the torque sensor (33) is used to detect the applied torque of the test sample (2) and transmit it to the control system (5).

8. The device for the slow energy consumption test method for evaluating the impact resistance of thermoplastic resin according to claim 6, characterized in that: The test sample (2) is a thin-walled circular ring, and flanges at both ends of the test sample (2) are bonded to the fixture (32).

9. The device for the slow energy consumption test method for evaluating the impact resistance of thermoplastic resin according to claim 6, characterized in that: The optical strain measuring device (4) comprises two CCD cameras and a light source (41), wherein the CCD cameras are connected to a control system (5); the CCD cameras are used to take a torsional strain picture of the test sample (2).

10. The device for the slow energy consumption test method for evaluating the impact resistance of thermoplastic resin according to claim 6, characterized in that: The infrared thermal imager (1), the mechanical property testing equipment (3), and the optical strain measuring device (4) are connected to the control system (5) via a synchronous trigger (51).

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