A shear de-icing force measuring device

Abstract

The application relates to the technical field of low-temperature environment test and ice adhesion test, and discloses a shearing ice removing force measuring device which comprises a low-temperature box, a loading mechanism, a test piece and a control system. The low-temperature box is used for providing a test space and a controllable low-temperature environment; the loading mechanism is used for applying a shearing load to the test piece and collecting the shearing force; the test piece is composed of a base and accumulated ice and is installed on a fixed clamp. The control system performs graded temperature control based on a preset parameter table and a PID algorithm, drives a refrigeration unit to operate at full power when the temperature difference is large, and realizes constant temperature keeping through the cooperation of cold and hot power when the temperature approaches the set temperature; when a disturbance event is detected, the control system is automatically switched to an event-driven parameter table, and returns to the default parameter table after the recovery condition is met, so that rapid cooling, stable temperature control and disturbance compensation are realized. The application can accurately measure the shearing debonding force of the ice and the base interface, and enhances the stability and repeatability of experimental results.

Description

TECHNICAL FIELD

[0001] The present application relates to a deicing force measuring device, in particular to a low-temperature test device for ice and substrate interface shear debonding force, and belongs to the technical field of low-temperature environment test and ice adhesion test. BACKGROUND

[0002] Ice accumulation is a common natural phenomenon in low-temperature environments, involving key fields such as aviation, energy, transportation, and infrastructure, causing serious safety, economic, and reliability risks, and even triggering a series of catastrophic consequences. In order to study and evaluate the ice adhesion and debonding behavior on the surface of materials, accurate testing of deicing force becomes a key link in the development of deicing technology. Existing ice adhesion force testing devices usually create an icing environment in a low-temperature chamber and use a loading mechanism to apply tensile, push-pull or shear load to the test piece. Finally, the deicing force or adhesion strength data is collected and recorded by a force sensor.

[0003] However, the temperature control mode of such devices relies on the start-stop or power adjustment of the refrigeration unit. A single temperature control mode cannot balance rapid cooling and high-precision stability, especially when disturbances such as opening the box or phase change heat release occur, causing significant temperature fluctuations in the box, thereby affecting the constancy of the test environment and the repeatability of the experimental results. In addition, the force sensor readings of existing devices often have temperature drift effects, further weakening the stability and accuracy of measurements at different set temperatures. Therefore, providing a deicing force measuring device that can quickly approach the set temperature, maintain continuous temperature accuracy, and actively compensate for disturbances becomes an important technical problem to be solved in this field. SUMMARY

[0004] The purpose of the present application is to provide a shear deicing force measuring device to overcome the shortcomings of existing tests in temperature control and measurement accuracy, enabling rapid approach to the set temperature, maintaining continuous temperature accuracy, and actively compensating for disturbances, thereby improving the accuracy, stability, and repeatability of ice and substrate interface shear debonding force measurement.

[0005] To achieve the above purpose, the present application realizes the following technical solutions:

[0006] A shear deicing force measuring device, characterized in that it comprises a low-temperature chamber, a loading mechanism, a test piece, and a control system.

[0007] The low-temperature chamber comprises a chamber body, a chamber cover, and an equipment cabin. An evaporator is fixed on one side of the chamber body. A compressor and a condenser are fixed in the equipment cabin. The evaporator, compressor, and condenser are connected to each other to form a refrigeration unit. A heating glass window is provided on the chamber cover to form a heating unit.

[0008] The loading mechanism comprises an electric cylinder, a force sensor, a push head and a fixed clamp, the electric cylinder is arranged in the equipment cabin and fixed to the fixed clamp, the force sensor is mechanically connected with the electric cylinder and arranged along the loading direction, the push head is mechanically connected to the end of the force sensor away from the electric cylinder, the force sensor and the push head extend into the box through the side wall of the box, and the fixed clamp is composed of a mounting plate with an array of threaded holes and directly connected with the supporting leg;

[0009] The test piece is composed of a base and ice adhered to the base, and the base is fixedly installed on the fixed clamp through the mounting hole thereon;

[0010] The control system comprises a controller and monitoring and control software, the controller is electrically connected with the compressor, the heated glass window, a temperature sensor arranged in the box and the force sensor respectively, used for collecting the temperature signal and the shear force signal in the box and outputting the control signal to the refrigeration unit and the heating unit, and the monitoring and control software is electrically connected with the controller, used for testing parameter input and displaying collected data;

[0011] The controller performs temperature control based on a preset parameter table and a PID algorithm, wherein, T box T is the real-time temperature in the box, T set T is the set temperature, Δ T fast is a temperature difference threshold value for distinguishing between rapid adjustment and fine adjustment;

[0012] In the case where no disturbance event is detected, E the controller calls a default parameter table P0 to perform hierarchical temperature control, when T box - T set | ≥ Δ T fast , the refrigeration unit is controlled to operate at full power to realize rapid approximation of the temperature in the box to the set temperature, when T box - T set | ≤ Δ T fast , the controller enters a fine adjustment stage, and the output powers of the refrigeration unit and the heating unit are cooperatively adjusted through a cold-heat power ratio r , wherein the cold-heat power ratio r is located in a preset range [ r min , r max ] and changes with the sampling periodT s updating to realize stable holding of the temperature in the box;

[0013] In the hierarchical temperature control process, when a disturbance event E is detected, the controller switches to call an event-driven parameter table PE corresponding to the disturbance event, and performs disturbance compensation control on the refrigeration unit and the heating unit, and the recovery condition R is the deviation of the real-time temperature in the box from the set temperature T box - T set | ≤ Δ T recover and the state is continuously maintained for no less than t hold time, after the preset recovery condition R is met, the controller resumes calling the default parameter table P0 and continues to perform the hierarchical temperature control to realize rapid cooling, constant temperature holding and disturbance compensation.

[0014] Further, the heating glass window has a defogging function for ensuring observation clarity in a low-temperature environment; the temperature sensors are arranged in an array along the height and length directions on the inner wall of the box to realize multi-point temperature real-time acquisition and partition monitoring.

[0015] Further, the force sensor has a temperature compensation function, the temperature compensation function corrects the output signal of the force sensor based on a real-time temperature compensation parameter table to eliminate zero point deviation and sensitivity variation caused by temperature drift.

[0016] Further, the test piece is installed in the threaded hole on the fixed clamp through a single fixing bolt in the mounting hole on the base, and can be automatically aligned with the loading axis by rotating around the fixing bolt in the initial loading stage, so that the test efficiency and result accuracy are improved.

[0017] The present application has the following advantages:

[0018] (1) Through the hierarchical temperature control strategy of "rapid approximation + coordinated fine adjustment + disturbance compensation", rapid cooling and high-precision constant temperature are realized, and the temperature can be kept stable under disturbances such as opening the box or ice heat release.

[0019] (2) The gain scheduling mechanism based on the preset parameter table and the PID algorithm is adopted to realize dynamic switching of the main control and sub-control loops, avoid the lag and oscillation of single PID control, and improve the temperature control efficiency, adaptability and robustness.

[0020] (3) The parameter table compensation based on the set temperature and the real-time temperature signal is introduced to correct the measurement deviation of the force sensor caused by temperature drift in real time, and the accuracy and consistency of shear force measurement under low temperature conditions are improved.

[0021] (4) The test piece is installed in a single fixed bolt mode, can be automatically aligned with the loading axis in the initial loading stage, reduces the clamping error, and improves the test efficiency and measurement accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a schematic view of the front structure of the embodiment;

[0023] Figure 2 is a schematic view of the control flow of the embodiment;

[0024] In the figure, 1 is a low-temperature box; 101 is a box body; 102 is a box cover; 103 is an equipment cabin; 104 is a compressor; 105 is a condenser; 106 is an evaporator; 107 is a heating glass window; 108 is a temperature sensor; 2 is a loading mechanism; 201 is an electric cylinder; 202 is a force sensor; 203 is a push head; 204 is a fixed clamp; 205 is an array of threaded holes; 206 is a supporting leg; 3 is a test piece; 301 is ice accumulation; 302 is a base; 303 is a fixed bolt; 4 is a control system; 401 is a controller; 402 is monitoring and control software. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described clearly and completely in the description of the embodiments of the present application in combination with the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0026] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms “center”, “longitudinal”, “transverse”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer” and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application.

[0027] Reference Figure 1 and Figure 2The embodiment provides a shearing ice removal force measuring device, which comprises a low-temperature box 1, a loading mechanism 2, a test piece 3 and a control system 4. The low-temperature box 1 comprises a box body 101, a box cover 102 and a device cabin 103. An evaporator 106 is arranged in the box body 101, a compressor 104 and a condenser 105 are arranged in the device cabin 103, and the three constitute a refrigeration unit. The refrigeration unit can provide a low-temperature environment in the range of -30 DEG C to 0 DEG C, and the cooling rate can reach 1-3 DEG C / min. The box cover 102 is provided with a heating glass window 107 for fine adjustment and anti-fogging, so as to ensure the observation clarity under the low-temperature condition. The inner wall of the box body 101 is distributed with an array of temperature sensors 108, the sensors are arranged in zones along the height and length directions, the sampling accuracy is better than ±0.01 DEG C, and the real-time sampling and zoned control of multiple points can be realized.

[0028] Reference Figure 1 The loading mechanism 2 comprises an electric cylinder 201, a force sensor 202 and a push head 203. The electric cylinder 201 is fixed to a fixed clamp 204 in the device cabin 103, the push head 203 is connected with the force sensor 202, and the push head 203 is used for applying a shearing load to the test piece 3. The loading rate of the electric cylinder can be adjusted in the range of 0.5-50 mm / min, and the rated stroke is 100 mm. The force sensor 202 has a range of 0-1kN, an accuracy of 0.1%, and a temperature compensation function in the data acquisition link. Corresponding parameter tables are called based on the set temperature, and the output data are revised in combination with the real-time temperature signal, so that the zero-point deviation and sensitivity change caused by temperature drift are eliminated, and the measurement accuracy under the low-temperature environment below -20 DEG C is ensured.

[0029] Reference Figure 1 The test piece 3 is composed of a base 302 and ice accumulation 301, and the base 302 is installed on the fixed clamp 204 through a single fixed bolt 303. In the initial loading stage, the base 302 can be slightly rotated around the fixed bolt to automatically align the loading axis, so as to ensure the uniformity of the shearing force. The size of the test piece is generally 20 mm*20 mm, the ice thickness is about 10 mm, and the icing process is completed in situ in the low-temperature box.

[0030] Reference Figure 1 The control system 4 comprises a controller 401 and monitoring and control software 402. The controller 401 is electrically connected with the compressor 104, the heating glass window 107, the temperature sensor 108 and the force sensor 202.

[0031] Reference Figure 2 The control logic is as follows:

[0032] The controller collects the temperature signals in the box in real time and judges whether a disturbance event is detected.

[0033] In the case of no disturbance event being detected, the controller calls the default parameter table P0 to perform the hierarchical temperature control, when the difference between the real-time temperature inside the box and the set temperature is greater than Δ T box - T set | ≥ Δ T fast , the controller controls the refrigeration unit to operate at full power to realize the rapid approach of the temperature inside the box to the set temperature, wherein Δ T fast is the temperature difference threshold for distinguishing the rapid regulation and the fine regulation, the value of which can be set according to the system requirement, and the preferred range is 1-5℃; when T box - T set | ≤ Δ T fast , the controller enters the fine regulation stage, and the output powers of the refrigeration unit and the heating unit are cooperatively and smoothly regulated through a cold-heat power ratio r , and the preferred range of the cold-heat power ratio r is [0.1, 0.9].

[0034] In the hierarchical temperature control process, when the controller detects a disturbance event, an event-driven parameter table PE corresponding to the disturbance event is called to perform disturbance compensation control on the refrigeration unit and the heating unit; the recovery condition R is set as the deviation between the real-time temperature inside the box and the set temperature T box - T set | ≤ 0.5 ℃, and the state is continuously maintained t hold =60 s; when the preset recovery condition is met, the controller resumes calling the default parameter table P0 and continues to perform the hierarchical temperature control.

[0035] Through the above structure and control logic, the device can be reduced from room temperature to the set -30℃ in 5-10 min, and the temperature fluctuation is controlled within ±0.01℃, thereby ensuring the stability of the icing environment.

[0036] The use method of the present application in combination with the drawings is as follows:

[0037] 1) Test preparation and calibration

[0038] Select a force sensor 202 with a suitable range according to the test requirement, and replace the push head 203 with a corresponding length to ensure that its contact position matches the ice accumulation 301. After the loading mechanism 2 is assembled, it is electrically connected with the control system 4, and calibration can be completed in the standby state.

[0039] 2) Temperature control and logic setting

[0040] Temperature setting by monitoring and control software 402 T set (For example - 20 ℃). Controller 401 performs hierarchical temperature control logic according to temperature difference conditions, when T box - T set | ≥ Δ T fast (As Δ T fast 3 ℃) is set, the refrigeration unit is driven to run at full power to achieve rapid cooling; when T box - T set | ≤ Δ T fast , the system enters the cold / heat power collaborative regulation stage, realizing high-precision and high-efficiency constant temperature control.

[0041] 3) Sample preparation and specimen installation

[0042] The base 302 is fixed to the fixed clamp 204 by a single fixed bolt 303, deionized water is sprayed on the surface of the base 302, or ice molds are arranged and water is injected, the lid 102 of the low-temperature box 1 is closed, and the ice accumulation 301 is frozen to form under the low-temperature environment.

[0043] 4) Disturbance compensation and parameter switching

[0044] When a disturbance event E (such as temperature slope d T / d t ≥ 0.1 - 0.3 ℃ / s, or the opening angle of the lid is > 5°) is detected, the controller 401 automatically switches to the event parameter table PE for compensation. After the recovery condition R is met, the system returns to the default parameter table P0 to ensure the stability of temperature control.

[0045] 5) Loading and shear testing

[0046] The loading mode (displacement control or force control) is set on the software side, and the electric cylinder 201 drives the push head 203 to gradually contact the ice accumulation 301 at a rate of 10 mm / min. In the initial stage of loading, the specimen 3 can automatically rotate around the fixed bolt 303 to ensure that the push head 203 fully matches the ice accumulation 301 and aligns with the loading axis. With the continuation of loading, the push head 203 pushes the ice accumulation 301, and the force sensor 202 collects the shear force signal in real time, and combines the set temperature and real-time temperature signal to modify and compensate the parameter table. The modified data is transmitted to the computer side in real time.

[0047] 6) Data acquisition and result analysis

[0048] When the ice 301 debonds from the substrate 302, the shear force and displacement curve will show a sharp drop, which is the debonding force. The monitoring and control software 402 automatically records the curve and outputs the debonding force value. After the test is completed, the temperature in the box remains stable, and multiple repeated tests can be performed under the same conditions to verify the consistency and reliability of the results.

[0049] It should be noted that the above examples are only used to illustrate the technical concept and characteristics of the present application, and are intended to enable those skilled in the art to understand and implement the present application, and are not intended to limit the scope of protection. Any equivalent changes or modifications made in accordance with the spirit and essence of the present application shall be covered within the scope of protection of the present application.

Claims

1. A shear de-icing force measuring device characterized by, The device comprises a low-temperature box (1), a loading mechanism (2), a test piece (3) and a control system (4). The low-temperature box (1) comprises a box body (101), a box cover (102) and a device cabin (103), an evaporator (106) is fixed on one side in the box body (101), a compressor (104) and a condenser (105) are fixed in the device cabin (103), the evaporator (106), the compressor (104) and the condenser (105) are communicated with each other to form a refrigeration unit, a heating glass window (107) is arranged on the box cover (102) to form a heating unit. The loading mechanism (2) comprises an electric cylinder (201), a force sensor (202), a push head (203) and a fixed clamp (204), the electric cylinder (201) is arranged in the device cabin (103) and fixed to the fixed clamp (204), the force sensor (202) is mechanically connected with the electric cylinder (201) and arranged along the loading direction, the push head (203) is mechanically connected to one end of the force sensor (202) away from the electric cylinder (201), the force sensor (202) and the push head (203) penetrate through the side wall of the box body (101) and extend into the box body (101), and the fixed clamp (204) is composed of a mounting plate with a threaded hole array (205) and directly connected with a supporting leg (206). The test piece (3) is composed of a base (302) and ice accumulation (301) adhered to the base (302), and the base (302) is fixedly installed on the fixed clamp (204) through mounting holes thereon. The control system (4) comprises a controller (401) and monitoring and control software (402), the controller (401) is electrically connected with the compressor (104), the heating glass window (107), a temperature sensor (108) arranged in the box body (101) and the force sensor (202) respectively, used for collecting temperature signals and shear force signals in the box and outputting control signals to the refrigeration unit and the heating unit, and the monitoring and control software (402) is electrically connected with the controller (401), used for testing parameter input and displaying collected data. The controller (401) performs temperature control based on a preset parameter table and a PID algorithm, wherein, T box is a real-time temperature in the cabinet (101), T set is a set temperature, Δ T fast is a temperature difference threshold value for distinguishing between fast adjustment and fine adjustment; In the case where no disturbance event is detected E , the controller (401) invokes a default parameter table P0 to perform hierarchical temperature control, when T box - T set | ≥ Δ T fast , the controller controls the refrigeration unit to operate at full power to achieve rapid approach of the temperature inside the box to the set temperature, when T box - T set | ≤ Δ T fast , the controller (401) enters a fine adjustment stage, and cooperatively adjusts the output power of the refrigeration unit and the heating unit by a cold-heat power ratio r , wherein the cold-heat power ratio r is located within a preset range [ r min , r max ] and is updated with a sampling period T s to achieve stable maintenance of the temperature inside the box. In the hierarchical temperature control process, when a disturbance event is detected E , the controller (401) switches to call an event-driven parameter table PE corresponding to the disturbance event, and performs disturbance compensation control on the refrigeration unit and the heating unit. After the preset recovery condition R is met, the controller (401) resumes calling the default parameter table P0 and continues to perform the hierarchical temperature control to achieve rapid cooling, constant temperature maintenance, and disturbance compensation.

2. The device according to claim 1, wherein: The heating glass window (107) has an anti-fog function for ensuring the observation clarity in the low-temperature environment, and the temperature sensor (108) is arranged in the inner wall of the box body (101) in the height and length directions to realize the real-time collection and partition monitoring of multiple points.

3. The device according to claim 1, wherein: The force sensor (202) has a temperature compensation function, the temperature compensation function is based on the real-time temperature to call a compensation parameter table to correct the output signal of the force sensor (202) to eliminate the zero-point deviation and sensitivity change caused by the temperature drift.

4. The device according to claim 1, wherein: The test piece (3) is installed in the threaded hole on the fixing clamp (204) through the mounting hole on the base (302) by a single fixing bolt (303), and can be micro-rotated around the fixing bolt (303) in the initial loading stage to automatically align the loading axis, so as to improve the test efficiency and result accuracy.

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