Ice constant-temperature dynamic mechanical property testing device

Abstract

The application provides a kind of ice constant temperature dynamic mechanical property testing device, belongs to ice detection technical field, including launch subassembly, impact lever, incident support, incident lever, sample support, transmission support, transmission lever, data acquisition module and data processing module, the end face of impact lever towards incident lever is equipped with several spaced convex structures, the end face of incident lever towards impact lever is equipped with shaping piece, shaping piece is used to extend the rising time of incident stress wave that incident lever transmits to ice sample, the end face of incident lever towards ice sample is equipped with wave modulation module, wave modulation module is used to realize the wave impedance continuous gradient matching of incident stress wave from incident lever to ice sample, data processing module corrects the data collected by data acquisition module to obtain final incident wave strain and final transmission wave strain, and calculates the strain rate, stress and strain of ice sample.The application scheme improves the accuracy of ice constant temperature dynamic mechanical property test results.

Description

Technical Field

[0001] This application relates to the field of ice detection, and in particular to a device for testing the isothermal dynamic mechanical properties of ice. Background Technology

[0002] Aircraft often face severe dynamic loads during high-altitude flight, such as hail impacts and ice shedding impacts. High-strain-rate collisions between ice and critical structures can easily cause structural damage. Therefore, conducting high-strain-rate dynamic mechanical property tests on ice can provide crucial data support for ice impact-resistant design, simulation modeling, and airworthiness assessment of aircraft structures. However, dynamic mechanical property testing of ice places stringent requirements on the ice sample and ambient temperature: internal defects in the ice sample, installation deviations, and uncontrollable ambient temperatures can all lead to inaccurate test results. Summary of the Invention

[0003] In view of this, this application provides a thermostatic dynamic mechanical property testing device for ice, which solves the problems in the prior art and improves the accuracy of the thermostatic dynamic mechanical property testing results for ice.

[0004] The isothermal dynamic mechanical property testing device for ice provided in this application adopts the following technical solution:

[0005] A isothermal dynamic mechanical property testing device for ice includes a launching component, an impact rod, an incident support, an incident rod, a sample support, a transmission support, a transmission rod, a data acquisition module, and a data processing module. The incident rod is slidably mounted on the incident support, the transmission rod is slidably mounted on the transmission support, the sample support is located between the incident support and the transmission support, and the sample support is used to place the ice sample so that the ice sample is located between the incident rod and the transmission rod. The incident rod and the transmission rod are coaxially arranged, and the sliding direction of the incident rod and the transmission rod is along the axial direction of the incident rod. The launching assembly is located on the end of the incident rod facing away from the transmission rod. The impact rod is mounted on the launching end of the launching assembly. The impact rod and the incident rod are coaxially arranged. The launching assembly is used to provide the impact rod with force toward the incident rod so that the impact rod impacts the incident rod. The impact rod has several spaced protrusions on its end face facing the incident rod. The incident rod has a shaping plate on its end face facing the impact rod. The shaping plate is used to extend the rise time of the incident stress wave transmitted from the incident rod to the ice sample after the impact rod strikes the incident rod. The incident rod has a waveform modulation module on its end face facing the ice sample. The waveform modulation module is used to achieve continuous gradient matching of the wave impedance of the incident stress wave from the incident rod to the ice sample, and to filter the wave band of the incident stress wave at a preset frequency to suppress the resonance of the ice sample. Strain gauges are attached to both the incident rod and the transmission rod. The data acquisition module is used to acquire the initial incident wave strain from the strain gauges on the incident rod and the initial transmitted wave strain from the strain gauges on the transmission rod. The data processing module acquires the data acquired by the data acquisition module. After correcting the initial incident wave strain and the initial transmitted wave strain, the data processing module obtains the final incident wave strain and the final transmitted wave strain. Based on the final incident wave strain and the final transmitted wave strain, the strain rate, stress, and strain of the ice sample are calculated.

[0006] Optionally, the data processing module obtains the final incident wave strain and the final transmitted wave strain by correcting the initial incident wave strain and the initial transmitted wave strain as follows: First-order corrections are made to the initial incident wave strain and the initial transmitted wave strain to obtain the first-order incident wave strain and the first-order transmitted wave strain: ; ; in, For the initial incident wave strain, This refers to the contact area between the protruding structure on the impact bar and the shaping plate. This refers to the area of ​​the end face of the shaping piece facing the impact rod. This is a first-level correction factor. For time; The first-order frequency domain incident wave strain is obtained by performing Fourier transforms on the first-order incident wave strain and the first-order transmitted wave strain. and first-order frequency domain transmitted wave strain ; The second-order frequency domain incident wave strain is obtained by performing second-order corrections on the first-order frequency domain incident wave strain and the first-order frequency domain transmitted wave strain. and second-order frequency domain transmitted wave strain : ; ; in, For transfer functions, , Angular frequency, The attenuation coefficient of ice. For the thickness of the shaping sheet, These are the filter characteristic parameters; Strain of second-order frequency domain incident wave and second-order frequency domain transmitted wave strain The second-order incident wave strain is obtained by performing an inverse Fourier transform. and second-order transmitted wave strain ; strain of second-order incident wave and second-order transmitted wave strain The final incident wave strain is obtained by performing three-level corrections. and final transmitted wave strain : ; ; in, This is the equivalent wave impedance of the waveform modulation module. The wave impedance of ice, Let be the wave impedance of the incident rod.

[0007] Optionally, the steps for calculating the strain rate, stress, and strain of the ice sample based on the final incident wave strain and the final transmitted wave strain include: Calculate the strain of the final reflected wave : ; in, For the strain of the final incident wave, The strain is the final transmitted wave strain. Strain rate of ice sample for: ; ; ; in, The longitudinal wave velocity of the incident or transmitting rod. The length of the ice sample along the axial direction of the incident rod. This is the strain rate correction term caused by dispersion. This is the friction correction term for the interfacial strain rate between the ice sample and the incident or transmitted rod. This is the strain rate dispersion correction factor. For the thickness of the shaping sheet, Let be the coefficient of friction of ice. Let be the radius of the ice sample. The characteristic time of pressure melting; Stress of ice sample for: ; ; ; ; ; in, Let be the circumferential cross-sectional area of ​​the incident rod. Let be the circumferential cross-sectional area of ​​the ice sample. The elastic modulus of the incident rod, This is a stress correction term caused by dispersion. This is a temperature rise softening correction term. This is a correction term for the interfacial stress friction between the ice sample and the incident or transmitted rod. This is the stress dispersion correction factor. Let be the elastic modulus of ice. Let be the elastic modulus of the transmission rod. The temperature rise softening coefficient of ice. The adiabatic temperature rise of the ice sample during deformation is given. The heat conversion coefficient, The density of ice, The specific heat capacity of ice. For integration time variable, Values ​​range from 0 to , for The stress of the ice sample at any time, for The strain of the ice sample at any time, This refers to the contact area between the protruding structure on the impact bar and the shaping plate. This refers to the area of ​​the end face of the shaping piece facing the impact rod. Strain of ice sample for: ; in, The time variable is the integral time variable, and its value ranges from 0 to... , for The strain rate of the ice sample at any given time.

[0008] Optionally, the shaping sheet has a three-layer composite structure, with the middle layer being aramid paper and the outer layers being an aluminum sheet and a polyethylene film, respectively. The aluminum sheet is located on the side closer to the incident rod, and the polyethylene film is located on the side closer to the impact rod.

[0009] Optionally, both the incident rod and the transmission rod are made of aluminum. The waveform modulation module consists of a steel sheet, a copper sheet, an aluminum sheet, and a nylon sheet in sequence. The steel sheet is welded to the end face of the incident rod, and the nylon sheet is used to contact the ice sample. The steel sheet, copper sheet, and aluminum sheet are connected by welding, and the nylon sheet is bonded to the aluminum sheet.

[0010] Optionally, the launching assembly includes a gas chamber and a launching tube, the launching tube being located on the side of the gas chamber, the gas chamber storing compressed gas, the gas chamber having an exhaust channel communicating with the launching tube, the exhaust channel having an electromagnetic valve, the launching tube and the incident rod being coaxial, and the impact rod being located in the launching tube.

[0011] Optionally, the sample holder includes two opposing support plates and a support block. The support block is located between the two support plates and is mounted on the support plates by bolts. Each support plate has at least two parallel waist-shaped grooves distributed in the vertical direction. The bolts pass through the waist-shaped grooves and are threadedly connected to the support block. The top surface of the support block has a V-shaped groove for placing ice samples.

[0012] Optionally, the isothermal dynamic mechanical property testing device for ice also includes an insulated chamber, a cold source, and a temperature sensor. The insulated chamber is wrapped around the outer periphery of the sample holder, and the insulated chamber is provided with through holes for the incident rod and the transmission rod to pass through. The cold source is connected to the insulated chamber through a delivery pipe, and the delivery pipe is provided with a control valve. The control valve is used to control the opening and closing of the cold source delivering the cooling medium into the insulated chamber. The probe of the temperature sensor is located inside the insulated chamber, and the display end of the temperature sensor is located outside the insulated chamber.

[0013] In summary, this application includes the following beneficial technical effects: This application reduces the problem of diffuse oscillation of the incident waveform caused by lateral inertia effect by designing the impact rod end face, shaping plate and waveform modulation module, eliminates the negative impact of internal inhomogeneity of ice sample, and can make the stress reached by ice sample more uniform; and corrects the collected parameters and the calculation process of strain rate, stress and strain of ice sample, thereby improving the accuracy of the final test results. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the overall structure of the isothermal dynamic mechanical property testing device for ice according to an embodiment of this application. Figure 2 This is a schematic diagram of the sample holder structure.

[0016] Explanation of reference numerals in the attached drawings: 1. Base; 11. Buffer plate; 21. Gas chamber; 22. Launch tube; 23. Impact rod; 3. Injection bracket; 31. Injection rod; 4. Sample holder; 41. Support plate; 42. Support block; 43. Waist-shaped groove; 44. V-groove; 5. Transmission bracket; 51. Transmission rod; 6. Data acquisition module; 7. Data processing module; 8. Shaping plate; 9. Waveform modulation module; 10. Insulation box; 101. Cold source; 102. Temperature sensor; 103. Control valve; 110. Strain gauge. Detailed Implementation

[0017] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0018] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0020] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0022] This application provides a device for testing the isothermal dynamic mechanical properties of ice.

[0023] like Figure 1 and Figure 2 As shown, a isothermal dynamic mechanical property testing device for ice includes a base 1, a launching component, an impact rod 23, an incident support 3, an incident rod 31, a sample holder 4, a transmission support 5, a transmission rod 51, a data acquisition module 6, and a data processing module 7. The base 1 is mounted on a test bench, and the launching component, the incident support 3, the sample holder 4, and the transmission support 5 are mounted on the base 1. The incident support 3 supports both ends of the incident rod 31, and the transmission support 5 supports both ends of the transmission rod 51. The impact rod 23, the incident rod 31, the transmission rod 51, and the ice sample are all cylindrical, and the incident rod 31 and the transmission rod 51 have the same diameter.

[0024] The incident rod 31 is slidably mounted on the incident bracket 3, and the transmission rod 51 is slidably mounted on the transmission bracket 5. The incident bracket 3 has annular structures sleeved on the outer periphery of the incident rod 31 at both ends corresponding to the incident rod 31, which are used to guide the sliding of the incident rod 31. The transmission bracket 5 has annular structures sleeved on the outer periphery of the transmission rod 51 at both ends corresponding to the transmission rod 51, which are used to guide the sliding of the transmission rod 51. The sample holder 4 is located between the incident bracket 3 and the transmission bracket 5. The sample holder 4 is used to place the ice sample so that the ice sample is located between the incident rod 31 and the transmission rod 51. The incident rod 31 and the transmission rod 51 are coaxially arranged, and the sliding direction of the incident rod 31 and the transmission rod 51 is along the axial direction of the incident rod 31.

[0025] The launching assembly is located on the end of the incident rod 31 facing away from the transmission rod 51. The impact rod 23 is mounted on the launching end of the launching assembly. The impact rod 23 and the incident rod 31 are coaxially arranged. The launching assembly is used to provide the impact rod 23 with power toward the incident rod 31 so that the impact rod 23 impacts the incident rod 31. A buffer plate 11 is provided on the side of the transmission rod 51 facing away from the incident rod 31 and mounted on the base 1. The buffer plate 11 is used to limit the displacement of the transmission rod 51, so as to prevent the transmission rod 51 from flying out too far under force and to prevent the transmission rod 51 from detaching from the transmission bracket 5.

[0026] The impact rod 23 has several spaced protrusions on its end face facing the incident rod 31. These protrusions form multiple loading points on the end face of the impact rod 23, preventing stress concentration during impact and improving the uniformity of loading when impacting the incident rod 31. The end face of the protrusions facing the incident rod 31 is flat. The end face of the incident rod 31 facing the impact rod 23 has a shaping piece 8, which extends the rise time of the incident stress wave transmitted from the incident rod 31 to the ice sample after the impact rod 23 impacts the incident rod 31. The end face of the incident rod 31 facing the ice sample has a waveform modulation module 9, which achieves continuous gradient matching of the wave impedance of the incident stress wave from the incident rod 31 to the ice sample, improves the signal strength of the transmitted wave, and filters the high-frequency band of the incident stress wave at a preset frequency to suppress the resonance of the ice sample. In this embodiment, the preset frequency range for ice samples with a diameter of 10-20 mm and an axial length of 25-50 mm is 1200 Hz-15000 Hz.

[0027] Strain gauges 110 are attached to both the incident rod 31 and the transmission rod 51. The data acquisition module 6 is used to acquire the initial incident wave strain from the strain gauges 110 on the incident rod 31 and the initial transmitted wave strain from the strain gauges 110 on the transmission rod 51. The data processing module 7 acquires the data acquired by the data acquisition module 6, corrects the initial incident wave strain and the initial transmitted wave strain to obtain the final incident wave strain and the final transmitted wave strain, and calculates the strain rate, stress, and strain of the ice sample based on the final incident wave strain and the final transmitted wave strain. The data acquisition module 6 includes a signal conditioning module and a data acquisition card, which are existing technologies. The data acquisition module 6 sends the acquired data to the data processing module 7, which is a computer. In this embodiment, a high-speed camera is installed inside the insulation box 10. The high-speed camera's shooting range covers the end of the incident rod 31 near the ice sample, the ice sample, and the end of the transmission rod 51 near the ice sample, and is used to record the process of the incident rod 31 impacting the ice sample.

[0028] This application reduces the problem of diffuse oscillation of the incident waveform caused by lateral inertia effect through the design of the end face of the impact rod 23, the shaping plate 8, and the waveform modulation module 9, and eliminates the negative impact of internal inhomogeneity of the ice sample. This can make the stress reached by the ice sample more uniform, thereby improving the accuracy of the final test results.

[0029] In this embodiment, the shaping sheet 8 has a three-layer composite structure. The middle layer of the shaping sheet 8 is aramid paper, and the outer layers are an aluminum sheet and a polyethylene film. The aluminum sheet is located near the incident rod 31, and the polyethylene film is located near the impact rod 23. The three layers of the shaping sheet 8 are bonded together, and the shaping sheet 8 is circular with a diameter larger than that of the incident rod 31. The middle layer is formed by stacking two to three layers of aramid paper with a total thickness of 0.6 mm, which is used to increase energy dissipation; the aluminum sheet is a 1060-O state soft aluminum sheet with a thickness of 0.5 mm, which is used to provide the main plastic deformation; the polyethylene film has a thickness of 0.9-1.6 mm.

[0030] Both the incident rod 31 and the transmission rod 51 are made of aluminum. The waveform modulation module 9 consists of a steel sheet, a copper sheet, an aluminum sheet, and a nylon sheet. The steel sheet is vacuum brazed onto the end face of the incident rod 31. The nylon sheet is used to contact the ice sample. The steel sheet, copper sheet, and aluminum sheet are connected by vacuum brazing. The nylon sheet is bonded to the aluminum sheet. The thickness of the steel sheet, copper sheet, aluminum sheet, and nylon sheet is 8 mm.

[0031] The launching assembly includes a gas chamber 21 and a launching tube 22. The launching tube 22 is located on the side of the gas chamber 21. The gas chamber 21 stores compressed gas and has an exhaust channel communicating with the launching tube 22. An electromagnetic valve is installed on the exhaust channel. The launching tube 22 and the incident rod 31 are coaxial, and the impact rod 23 is located in the launching tube 22. When the impact rod 23 is launched, the electromagnetic valve is opened, and high-pressure gas instantly enters the launching tube 22, forming a stable thrust in the axial direction. This pushes the impact rod 23 to move in a straight line along the launching tube 22 with acceleration, and finally impacts the incident rod 31.

[0032] The sample holder 4 includes two opposing support plates 41 and a support block 42. The support block 42 is located between the two support plates 41 and is bolted to the support plates 41. Each support plate 41 has at least two parallel, vertically distributed waist-shaped grooves 43. The bolts pass through the waist-shaped grooves 43 and are threadedly connected to the support block 42. The top surface of the support block 42 has a V-shaped groove 44 for placing the ice sample. By adjusting the position of the bolts on the waist-shaped grooves 43, the height of the support block 42 is adjusted to make the ice sample and the incident rod 31 coaxial.

[0033] The isothermal dynamic mechanical property testing device for ice also includes an insulated box 10, a cold source 101, and a temperature sensor 102. The insulated box 10 is wrapped around the sample holder 4, and the insulated box 10 has through holes for the incident rod 31 and the transmission rod 51 to pass through. The cold source 101 is connected to the insulated box 10 through a delivery pipe, and the delivery pipe is equipped with a control valve 103. The control valve 103 is used to control the opening and stopping of the delivery of cooling medium from the cold source 101 to the insulated box 10. The probe of the temperature sensor 102 is located inside the insulated box 10, and the display end of the temperature sensor 102 is located outside the insulated box 10. The insulated box 10 is made of foam material, and the inner wall is covered with multiple layers of tin foil. The temperature sensor 102 is a thermocouple. The cold source 101 is a liquid nitrogen tank containing liquid nitrogen. When the control valve 103 is opened, low-temperature nitrogen gas enters the insulated box 10.

[0034] The operator controls the opening and closing of the control valve 103 based on the temperature value detected by the temperature sensor 102, so as to maintain the insulation box 10 at the preset temperature, ensure the ambient temperature of the ice sample, and improve the accuracy of the final test results.

[0035] The data processing module obtains the final incident wave strain and final transmitted wave strain by correcting the initial incident wave strain and initial transmitted wave strain as follows: First-order corrections are made to the initial incident wave strain and the initial transmitted wave strain to obtain the first-order incident wave strain and the first-order transmitted wave strain: ; ; in, For the initial incident wave strain, The contact area between the protruding structure on the impact rod 23 and the shaping piece 8. The area of ​​the end face of the shaping piece 8 facing the impact rod 23. This is a first-level correction factor. For time; The first-order frequency domain incident wave strain is obtained by performing Fourier transforms on the first-order incident wave strain and the first-order transmitted wave strain. and first-order frequency domain transmitted wave strain ; The second-order frequency domain incident wave strain is obtained by performing second-order corrections on the first-order frequency domain incident wave strain and the first-order frequency domain transmitted wave strain. and second-order frequency domain transmitted wave strain : ; ; in, For transfer functions, , Angular frequency, The attenuation coefficient of ice. The thickness of the shaping sheet is 8. These are the filter characteristic parameters; Strain of second-order frequency domain incident wave and second-order frequency domain transmitted wave strain The second-order incident wave strain is obtained by performing an inverse Fourier transform. and second-order transmitted wave strain ; strain of second-order incident wave and second-order transmitted wave strain The final incident wave strain is obtained by performing three-level corrections. and final transmitted wave strain : ; ; in, This is the equivalent wave impedance of waveform modulation module 9. The wave impedance of ice, Let be the wave impedance of the incident rod 31.

[0036] The steps for calculating the strain rate, stress, and strain of an ice sample based on the final incident wave strain and the final transmitted wave strain include: Calculate the strain of the final reflected wave : ; in, For the strain of the final incident wave, The strain is the final transmitted wave strain. Strain rate of ice sample for: ; ; ; in, The longitudinal wave velocity of the incident rod 31 or the transmission rod 51. The length of the ice sample along the axial direction of the incident rod 31. This is the strain rate correction term caused by dispersion. This is the frictional correction term for the interfacial strain rate between the ice sample and the incident rod 31 or the transmission rod 51. This is the strain rate dispersion correction factor. The thickness of the shaping sheet is 8. Let be the coefficient of friction of ice. Let be the radius of the ice sample. The characteristic time of pressure melting; Stress of ice sample for: ; ; ; ; ; in, Let be the circumferential cross-sectional area of ​​the incident rod 31. Let be the circumferential cross-sectional area of ​​the ice sample. The elastic modulus of the incident rod 31, This is a stress correction term caused by dispersion. This is a temperature rise softening correction term. This is a correction term for the interface stress friction between the ice sample and the incident rod 31 or the transmission rod 51. This is the stress dispersion correction factor. Let be the elastic modulus of ice. Let be the elastic modulus of the transmission rod 51. The temperature rise softening coefficient of ice. The adiabatic temperature rise of the ice sample during deformation is given. The heat conversion coefficient, The density of ice, The specific heat capacity of ice. For integration time variable, Values ​​range from 0 to , for The stress of the ice sample at any time, for The strain of the ice sample at any time, The contact area between the protruding structure on the impact rod 23 and the shaping piece 8. The area of ​​the end face of the shaping piece 8 facing the impact rod 23; Strain of ice sample for: ; in, The time variable is the integral time variable, and its value ranges from 0 to... , for The strain rate of the ice sample at any given time.

[0037] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A device for testing the isothermal dynamic mechanical properties of ice, characterized in that, It includes a launching assembly, an impact rod (23), an incident support (3), an incident rod (31), a sample holder (4), a transmission support (5), a transmission rod (51), a data acquisition module (6), and a data processing module (7); The incident rod (31) is slidably mounted on the incident bracket (3), the transmission rod (51) is slidably mounted on the transmission bracket (5), the sample holder (4) is located between the incident bracket (3) and the transmission bracket (5), the sample holder (4) is used to place the ice sample so that the ice sample is located between the incident rod (31) and the transmission rod (51), the incident rod (31) and the transmission rod (51) are coaxially arranged, and the sliding direction of the incident rod (31) and the transmission rod (51) is along the axial direction of the incident rod (31); The launching assembly is located on the end of the incident rod (31) facing away from the transmission rod (51). The impact rod (23) is mounted on the launching end of the launching assembly. The impact rod (23) and the incident rod (31) are coaxially arranged. The launching assembly is used to provide the impact rod (23) with a force toward the incident rod (31) so that the impact rod (23) impacts the incident rod (31). The impact rod (23) has several spaced protrusions on its end face facing the incident rod (31). The incident rod (31) has a shaping piece (8) on its end face facing the impact rod (23). The shaping piece (8) is used to extend the rise time of the incident stress wave transmitted from the incident rod (31) to the ice sample after the impact rod (23) impacts the incident rod (31). The incident rod (31) has a waveform modulation module (9) on its end face facing the ice sample. The waveform modulation module (9) is used to achieve continuous gradient matching of the wave impedance of the incident stress wave from the incident rod (31) to the ice sample, and to filter the wave band of the incident stress wave at a preset frequency to suppress the resonance of the ice sample. Strain gauges (110) are attached to both the incident rod (31) and the transmission rod (51). The data acquisition module (6) is used to acquire the initial incident wave strain from the strain gauges (110) on the incident rod (31) and the initial transmitted wave strain from the strain gauges (110) on the transmission rod (51). The data processing module (7) acquires the data acquired by the data acquisition module (6). The data processing module (7) corrects the initial incident wave strain and the initial transmitted wave strain to obtain the final incident wave strain and the final transmitted wave strain. The strain rate, stress and strain of the ice sample are calculated based on the final incident wave strain and the final transmitted wave strain.

2. The isothermal dynamic mechanical property testing device for ice according to claim 1, characterized in that, The data processing module obtains the final incident wave strain and the final transmitted wave strain by correcting the initial incident wave strain and the initial transmitted wave strain as follows: First-order corrections are made to the initial incident wave strain and the initial transmitted wave strain to obtain the first-order incident wave strain and the first-order transmitted wave strain: ； ; in, For the initial incident wave strain, The contact area between the protruding structure on the impact rod (23) and the shaping piece (8) is... The area of ​​the end face of the shaping piece (8) facing the impact rod (23) This is a first-level correction factor. For time; The first-order frequency domain incident wave strain is obtained by performing Fourier transforms on the first-order incident wave strain and the first-order transmitted wave strain. and first-order frequency domain transmitted wave strain ; The second-order frequency domain incident wave strain is obtained by performing second-order corrections on the first-order frequency domain incident wave strain and the first-order frequency domain transmitted wave strain. and second-order frequency domain transmitted wave strain : ； ； in, For transfer functions, , Angular frequency, The attenuation coefficient of ice. For the thickness of the shaping piece (8), These are the filter characteristic parameters; Strain of second-order frequency domain incident wave and second-order frequency domain transmitted wave strain The second-order incident wave strain is obtained by performing an inverse Fourier transform. and second-order transmitted wave strain ; strain of second-order incident wave and second-order transmitted wave strain The final incident wave strain is obtained by performing three-level corrections. and final transmitted wave strain : ； ； in, The equivalent wave impedance of the waveform modulation module (9) is... The wave impedance of ice, Let be the wave impedance of the incident rod (31).

3. The isothermal dynamic mechanical property testing device for ice according to claim 2, characterized in that, The steps for calculating the strain rate, stress, and strain of an ice sample based on the final incident wave strain and the final transmitted wave strain include: Calculate the strain of the final reflected wave : ； in, For the strain of the final incident wave, The strain is the final transmitted wave strain; Strain rate of ice sample for: ； ； ; in, The longitudinal wave velocity of the incident rod (31) or the transmission rod (51) The length of the ice sample along the axial direction of the incident rod (31) is given. This is the strain rate correction term caused by dispersion. This is the frictional correction term for the interfacial strain rate between the ice sample and the incident rod (31) or the transmission rod (51). This is the strain rate dispersion correction factor. For the thickness of the shaping piece (8), Let be the coefficient of friction of ice. Let be the radius of the ice sample. The characteristic time of pressure melting; Stress of ice sample for: ； ； ； ； ； in, Let be the circumferential cross-sectional area of ​​the incident rod (31). Let be the circumferential cross-sectional area of ​​the ice sample. The elastic modulus of the incident rod (31) is... This is a stress correction term caused by dispersion. This is a temperature rise softening correction term. This is a correction term for the interface stress friction between the ice sample and the incident rod (31) or the transmission rod (51). This is the stress dispersion correction factor. Let be the elastic modulus of ice. Let be the elastic modulus of the transmission rod (51). The temperature rise softening coefficient of ice. The adiabatic temperature rise of the ice sample during deformation is given. The heat conversion coefficient, The density of ice, The specific heat capacity of ice. For integration time variable, Values ​​range from 0 to , for The stress of the ice sample at any time, for The strain of the ice sample at any time, The contact area between the protruding structure on the impact rod (23) and the shaping piece (8) is... The area of ​​the end face of the shaping piece (8) facing the impact rod (23); Strain of ice sample for: ； in, The time variable is the integral time variable, and its value ranges from 0 to... , for The strain rate of the ice sample at any given time.

4. The isothermal dynamic mechanical property testing device for ice according to claim 1, characterized in that, The shaping sheet (8) has a three-layer composite structure. The middle layer of the shaping sheet (8) is aramid paper, and the surface layers of the shaping sheet (8) are aluminum sheet and polyethylene film, respectively. The aluminum sheet is located on the side closer to the incident rod (31), and the polyethylene film is located on the side closer to the impact rod (23).

5. The isothermal dynamic mechanical property testing device for ice according to claim 1, characterized in that, The incident rod (31) and the transmission rod (51) are both made of aluminum. The waveform modulation module (9) consists of a steel sheet, a copper sheet, an aluminum sheet and a nylon sheet in sequence. The steel sheet is welded to the end face of the incident rod (31). The nylon sheet is used to contact the ice sample. The steel sheet, copper sheet and aluminum sheet are connected by welding. The nylon sheet is bonded to the aluminum sheet.

6. The isothermal dynamic mechanical property testing device for ice according to claim 1, characterized in that, The launching assembly includes a gas chamber (21) and a launching tube (22). The launching tube (22) is located on the side of the gas chamber (21). The gas chamber (21) stores compressed gas. The gas chamber (21) is provided with an exhaust channel that communicates with the launching tube (22). The exhaust channel is provided with an electromagnetic valve. The launching tube (22) and the incident rod (31) are coaxial. The impact rod (23) is located in the launching tube (22).

7. The isothermal dynamic mechanical property testing device for ice according to claim 1, characterized in that, The sample holder (4) includes two opposing support plates (41) and a support block (42). The support block (42) is located between the two support plates (41) and is mounted on the support plates (41) by bolts. Each support plate (41) has at least two parallel waist-shaped grooves (43) distributed in the vertical direction. The bolts pass through the waist-shaped grooves (43) and the support block (42) and are threaded together. The top surface of the support block (42) is provided with a V-shaped groove (44) for placing ice samples.

8. The isothermal dynamic mechanical property testing device for ice according to claim 1, characterized in that, The isothermal dynamic mechanical property testing device for ice also includes an insulated box (10), a cold source (101), and a temperature sensor (102). The insulated box (10) is wrapped around the outer periphery of the sample holder (4), and the insulated box (10) is provided with through holes for the incident rod (31) and the transmission rod (51) to pass through. The cold source (101) is connected to the insulated box (10) through a delivery pipe. The delivery pipe is provided with a control valve (103). The control valve (103) is used to control the opening and stopping of the cold source (101) delivering the cooling medium to the insulated box (10). The probe of the temperature sensor (102) is located in the insulated box (10), and the display end of the temperature sensor (102) is located outside the insulated box (10).

Images