A force-heat combined testing device for a test piece under a temperature environment
By designing a combined force-thermal test device, the problem of simulating the complex environment of the aircraft during launch and high-altitude operation was solved, and the force-thermal coupling stress of the test piece was applied to ensure the performance test of the test piece under simulated environment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TIANJIN AEROSPACE RELIA TECH
- Filing Date
- 2026-05-13
- Publication Date
- 2026-07-17
AI Technical Summary
Existing technologies are insufficient to effectively simulate the complex temperature and mechanical environment of aircraft during launch and high-altitude operations, which pose challenges to electronic components and structural parts, especially the effects of alternating high and low temperatures and aerodynamic heating.
A combined force and heat testing device was designed, including a temperature test chamber, a force loading device, a heat loading device, and a control and measurement system. It can simulate force loads of 0~100kN and heat loads of -40℃~800℃. Closed-loop control of force and temperature is achieved through hydraulic cylinders, quartz lamps, and sensors.
It realizes the application of force-thermal coupling stress to the test specimen in a complex environment, provides a feasible solution, and ensures the performance test of the test specimen in the simulated environment.
Smart Images
Figure CN122409335A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of environmental testing technology, specifically relating to a combined mechanical and thermal testing device for test specimens under temperature conditions. Background Technology
[0002] The temperature environment during spacecraft launch is complex and variable, mainly divided into the low temperature / high temperature environment during the ground launch phase and the temperature change impact environment during the high-altitude ascent phase. The combination of these two forms a double test for electronic components, and the temperature environment varies significantly under different launch scenarios.
[0003] During the ground launch phase, the temperature environment is mainly affected by the location, season, and time of day of the launch site. In high-latitude regions or during winter launches, the ground temperature can drop as low as -40°C. This sustained low temperature will affect the spacecraft's cabin and internal components in advance. In low-latitude regions or during summer launches, the ground temperature in some areas can reach over 50°C. Combined with the heat radiation from the launch pad, the surface temperature of the cabin may rise further. In addition, at the moment of launch ignition, the engine exhaust flame will generate high-temperature radiation. Although it mainly affects the launch pad and the bottom of the cabin, it will still indirectly affect the internal temperature through heat conduction, creating a short-term high-temperature superposition effect.
[0004] During the ascent phase at high altitudes, the aircraft rapidly increases its speed, breaking from subsonic to supersonic and hypersonic speeds. Aerodynamic friction generates a large amount of aerodynamic heat on the cabin surface, simultaneously creating aerodynamic loads. This leads to a sharp increase in cabin temperature, and the cabin also experiences stress and bending moments due to these aerodynamic loads. At the same time, the thin atmosphere at high altitudes significantly reduces heat dissipation efficiency, making it difficult for the cabin heat to dissipate quickly. This rapid temperature change from high (or low) ground temperatures to aerodynamically heated high temperatures creates a strong temperature shock, with a more significant impact on electronic components. Under the combined effects of aerodynamic heat and aerodynamic heating, the performance of the aircraft's structural components also faces severe challenges.
[0005] Based on this situation, the present invention employs a high and low temperature environment test chamber and a combined force and heat test system to reproduce the complex environment of a circular module from launch to flight, i.e., a combined force and heat test device for a circular module based on simulated launch environment temperature. The high and low temperature environment test chamber is used to simulate or reproduce the local ambient temperature and is a unique test device for the combined force and heat test of a circular module. The temperature range of the test chamber is -40℃ to 80℃, while the combined force and heat test system can reproduce the aerodynamic loads and aerodynamic heat of the circular module during launch and flight. The force load range is 0~100kN, and the heat load range is -40℃ to 800℃. Summary of the Invention
[0006] To address the shortcomings of existing technologies, this invention provides a combined mechanical and thermal testing device for test specimens under temperature conditions.
[0007] This invention provides the following technical solution: A combined force and heat testing apparatus for test specimens under temperature conditions includes a temperature test chamber, a test bench disposed within the temperature test chamber, a support plate, a test specimen fixing base plate, and a cylindrical test specimen connected sequentially from bottom to top on the test bench, and further includes a force loading device, a heat loading device, and a control and measurement system, wherein: The test bench includes a base and a support frame, and the support plate is connected to the base; The force loading device includes a force load loading fixture, hydraulic cylinder I, hydraulic cylinder II, and hydraulic cylinder fixing base. Hydraulic cylinder I and hydraulic cylinder II are arranged above or above and below the force load loading fixture, and the top of the test piece is connected to the lower end face of the force load loading fixture. The heat loading device includes a hollow cylindrical reflector with openings at the top and bottom. The reflector is positioned on the outside of the test piece. Quartz lamps are installed on the inner wall of the reflector in the gap between the test piece and the reflector. There are two sets of quartz lamps, one above the other. Support legs are provided below the reflector. The control and measurement system includes a control host computer, a controller, servo valve I, servo valve II, an oil source, power control cabinet I, power control cabinet II, a measurement host computer, a data acquisition instrument, force sensor I, force sensor II, strain gauges, displacement sensors, and K-type thermocouples.
[0008] Furthermore, the hydraulic cylinders I and II are arranged on both sides above the force load loading fixture, and the bottoms of the hydraulic cylinders I and II are connected to the lower top of the support frame through hydraulic cylinder fixing bases.
[0009] Furthermore, the hydraulic cylinders I and II are respectively positioned above and below the force load loading fixture, and the bottoms of the hydraulic cylinders I and II are connected to the lower top of the support frame and the base respectively through hydraulic cylinder fixing bases.
[0010] Furthermore, the reflector includes an upper reflector and a lower reflector connected vertically. The lower end of the upper reflector and the upper end of the lower reflector both extend outward to form flange ends. An annular partition is provided inward at the lower end of the upper reflector, and a connecting piece for connecting the support leg extends outward at the lower end of the lower reflector.
[0011] Furthermore, the temperature test chamber includes a chamber body, and an air duct is provided inside the chamber body. The lower end of the air duct is an air inlet, and the upper end is an air outlet. A heat exchanger, an electric heater, a fan, and a temperature sensor are arranged sequentially from the air inlet to the air outlet inside the air duct.
[0012] Furthermore, the host computer is connected to the controller for editing the target spectrum, transmitting monitoring commands, and displaying signal feedback. The controller is connected to servo valve I and servo valve II for controlling the opening of the servo valves to ensure stable loading of the force load. The oil source is connected to servo valve I and servo valve II to ensure the supply of hydraulic oil. The piston rods of cylinder I and cylinder II are respectively equipped with cylinder extension rod I and cylinder extension rod II. Servo valve I, cylinder I, force sensor I, cylinder extension rod I, force load loading fixture, and test piece are connected in sequence. Servo valve II, cylinder II, force sensor II, cylinder extension rod II, force load loading fixture, and test piece are connected in sequence to ensure that the cylinders stably apply the force load. Force sensor I and force sensor II are connected to the controller to provide real-time feedback of force load data, thereby realizing closed-loop control of the force load device.
[0013] Furthermore, the controller is connected to power control cabinet I and power control cabinet II to realize the power output and proportional control of the power control cabinet. Power control cabinet I and power control cabinet II are respectively connected to copper busbar I and copper busbar II via cables. Copper busbar I and copper busbar II are respectively connected to the upper and lower groups of quartz lamps via the cables of the quartz lamps to heat the surface of the test piece. The surface temperature of the test piece is transmitted to the controller in real time through the K-type thermocouple attached to the surface of the test piece to achieve closed-loop temperature control.
[0014] Furthermore, the host computer for measurement is connected to the data acquisition instrument to realize real-time data acquisition, visualization, and storage. The strain gauges and K-type thermocouples are attached to the surface of the test piece and connected to the data acquisition instrument to realize data acquisition and real-time transmission of measuring points on the test piece surface. The displacement sensor is connected to the data acquisition instrument and a ceramic extension rod is installed at its tip. The ceramic extension rod passes through the reserved hole of the reflector and contacts the surface of the test piece to collect displacement changes of the measuring points in real time and transmit them to the measurement system. The data acquisition instrument is connected to the controller to realize time synchronization between the control system and the measurement system and prevent deviations from occurring during the data acquisition process and subsequent data processing.
[0015] Furthermore, the outer walls of the hydraulic cylinders I and II are provided with heat-insulating sleeves, and cooling water pipes are installed inside the heat-insulating sleeves.
[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention can achieve the application of force loads ranging from 0 to 100 kN and thermal loads ranging from -40°C to 800°C.
[0017] 2. This invention enables dual-channel force load control, where each channel corresponds to the application of one force load; and four-channel thermal load control, where each channel corresponds to the application of a zoned thermal load. It can simultaneously apply tensile, compressive, and bending moment loads, as well as different thermal loads to multiple zones on the test specimen; and utilizes PID control parameters for closed-loop adjustment of the loading system.
[0018] 3. The temperature test chamber of the present invention can reproduce the launch and transportation environment temperature of the test piece, realize the application of environmental-force-thermal coupling stress, and provide a feasible solution for this type of test. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the present invention; Figure 2 yes Figure 1 Schematic diagram of the equipment inside the medium-temperature test chamber; Figure 3 This is a diagram of the force loading method. Figure 1 ; Figure 4 This is a diagram of the force loading method. Figure 2 ; Figure 5 This is a schematic diagram showing the opposite directions of force loads; Figure 6 This is a schematic diagram showing the same direction of force loads; Figure 7 This is the front view of the test bench; Figure 8 This is a side view of the test bench; Figure 9 This is a top view of the test bench; Figure 10 This is a sectional view of the test specimen's fixing base plate; Figure 11 This is the main view of the force load loading fixture; Figure 12 This is a top view of the force load loading fixture; Figure 13 This is a schematic diagram of the reflector; Figure 14 This is a schematic diagram of the upper reflector; Figure 15 This is a schematic diagram of the heating zone division of the upper reflector; Figure 16 This is a schematic diagram of the lower reflector; Figure 17 This is a schematic diagram of the heating zone division of the lower reflector; Figure 18 This is a schematic diagram showing the test specimen and reflector mounted on the base; Figure 19 yes Figure 18 Side view; Figure 20 yes Figure 18 Longitudinal section view; Figure 21 This is a schematic diagram of the partition; Figure 22 This is a diagram of a bronze medal; Figure 23 This is a schematic diagram of an insulator; Figure 24 It is a schematic diagram of the combination of oil cylinder, insulation sleeve and cooling water pipeline; Figure 25 This is a schematic diagram of a displacement sensor mounted on a support frame; Figure 26 This is a schematic diagram of the operation of a displacement sensor; Figure 27 It is a schematic diagram of a control and measurement system; Figure 28 This is a schematic diagram of the control system connection; Figure 29 This is a connection diagram of the measurement system; Figure 30 This is a connection diagram for a temperature test chamber; Figure 31 This is a schematic diagram of a temperature test chamber; Figure 32 This is an external schematic diagram of the temperature test chamber.
[0020] Among them, 1-temperature test chamber, 111-chamber body, 112-air duct, 113-air inlet, 114-air outlet, 115-heat exchanger, 116-electric heater, 117-fan, 118-temperature sensor, 119-industrial computer, 120-refrigeration unit, 121-power cabinet, 2-test bench, 211-base, 212-support frame, 3-support plate, 4-test piece fixing base plate, 5-test piece, 6-force load loading fixture, 7-cylinder I, 711-cylinder extension rod I, 8-cylinder II, 811-cylinder extension rod II, 9-cylinder fixing base, 10-reflector, 1011-upper reflector, 1012-lower reflector, 1013-partition, 1014-connecting piece, 11-quartz lamp, 1111-upper quartz lamp group, 1112-lower resistance... Quartz lamp, 12-outrigger, 13-control host computer, 14-controller, 15-servo valve I, 16-servo valve II, 17-oil source, 18-power control cabinet I, 19-power control cabinet II, 20-measuring host computer, 21-data acquisition instrument, 22-force sensor I, 23-force sensor II, 24-displacement sensor, 25-copper busbar I, 26-copper busbar II, 27-ceramic extension rod, 28-reserved hole, 29-insulation sleeve, 30-cooling water pipeline, 31-heating zone I, 32-heating zone II, 33-heating zone III, 34-heating zone IV, 35-insulator I, 36-insulator II, 37-support frame, 38-personnel access door, 39-goods access door, 40-oil source pipeline inlet, 41-cable inlet, 42-signal line inlet, 43-observation window. Detailed Implementation
[0021] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.
[0022] like Figures 1-32 As shown, a combined force and heat testing device for test specimens under temperature conditions includes a temperature test chamber 1, a test bench 2 disposed within the temperature test chamber 1, a support plate 3, a test specimen fixing base plate 4, and a cylindrical test specimen 5 connected sequentially from bottom to top on the test bench 2, and further includes a force loading device, a heat loading device, and a control and measurement system, wherein: The test bench 2 includes a base 211 and a support frame 212, and the support plate 3 is connected to the base 211; The force loading device includes a force load loading fixture 6, hydraulic cylinder I 7, hydraulic cylinder II 8 and hydraulic cylinder fixing base 9. The hydraulic cylinder I 7 and hydraulic cylinder II 8 are arranged above or above and below the force load loading fixture 6. The top of the test piece 5 is connected to the lower end face of the force load loading fixture 6. The heat loading device includes a hollow cylindrical reflector plate 10 with openings at the top and bottom. The reflector plate 10 is located on the outside of the test piece 5. A quartz lamp 11 is installed on the inner wall of the reflector plate in the gap between the test piece 5 and the reflector plate 10. There are two sets of quartz lamps 11, one above the other. A support leg 12 is installed below the reflector plate 10. The control and measurement system includes a control host computer 13, a controller 14, servo valve I 15, servo valve II 16, an oil source 17, a power control cabinet I 18, a power control cabinet II 19, a measurement host computer 20, a data acquisition instrument 21, a force sensor I 22, a force sensor II 23, strain gauges, a displacement sensor 24, and a K-type thermocouple.
[0023] The combined force and heat testing device for the test piece under the specified temperature environment has cylinders I7 and II8 located on both sides above the force load loading fixture 6. The bottoms of cylinders I7 and II8 are connected to the lower top of the support frame 212 via cylinder fixing base 9.
[0024] The combined force and heat testing device for the test piece under the specified temperature environment has cylinders I7 and II8 respectively positioned above and below the force load loading fixture 6. The bottoms of cylinders I7 and II8 are connected to the lower top of the support frame 212 and the base 211 respectively via cylinder fixing base 9.
[0025] The aforementioned thermo-mechanical testing device for test specimens under temperature conditions includes an upper reflector 1011 and a lower reflector 1012 connected vertically. The lower ends of the upper reflector 1011 and the upper ends of the lower reflector 1012 both extend outward to form flange ends. An annular partition 1013 is provided inward at the lower end of the upper reflector 1011, and a connecting piece 1014 for connecting the support leg 12 extends outward at the lower end of the lower reflector 1012.
[0026] The combined mechanical and thermal testing device for test specimens under the specified temperature environment includes a temperature test chamber 1 comprising a chamber body 111. An air duct 112 is provided inside the chamber body 111. The lower end of the air duct 112 is an air inlet 113, and the upper end is an air outlet 114. A heat exchanger 115, an electric heater 116, a fan 117, and a temperature sensor 118 are sequentially arranged inside the air duct 112 from the air inlet 113 to the air outlet 114.
[0027] The aforementioned combined force and heat testing device for test specimens under temperature conditions has a host computer 13 connected to a controller 14 for editing target spectra, transmitting monitoring commands, and displaying signal feedback. The controller 14 is connected to servo valves I 15 and II 16 to control the opening of the servo valves, ensuring stable loading of force loads. The oil source 17 is connected to servo valves I 15 and II 16 to ensure the supply of hydraulic oil. Cylinder extension rods I 7 11 are respectively installed at the front end of the piston rods of cylinders I 7 and II 8. The servo valve I15, cylinder I7, force sensor I22, cylinder extension rod I711, force load loading fixture 6, and test piece 5 are connected in sequence with the cylinder extension rod II811. The cylinder II16, cylinder II8, force sensor II23, cylinder extension rod II811, force load loading fixture 6, and test piece 5 are also connected in sequence to ensure that the cylinder can stably apply force load. The force sensor I22 and force sensor II23 are connected to the controller 14 to provide real-time feedback of force load data, thereby realizing closed-loop control of the force load device.
[0028] The combined force and heat testing device for the test specimen under the described temperature environment has a controller 14 connected to power control cabinet I 18 and power control cabinet II 19 to realize the power output and proportional control of the power control cabinet. Power control cabinet I 18 and power control cabinet II 19 are respectively connected to copper busbar I 25 and copper busbar II 26 through cables. Copper busbar I 25 and copper busbar II 26 are respectively connected to the upper and lower groups of quartz lamps 11 through the cables of the quartz lamps, so as to heat the surface of the test specimen 5. The surface temperature of the test specimen is transmitted to the controller 14 in real time through the K-type thermocouple attached to the surface of the test specimen 5 to achieve closed-loop temperature control.
[0029] The aforementioned combined force and heat testing device for the test specimen under temperature conditions has a host computer 20 connected to a data acquisition instrument 21 to achieve real-time data acquisition, visualization, and storage. The strain gauges and K-type thermocouples are attached to the surface of the test specimen 5 and connected to the data acquisition instrument 21 to achieve data acquisition and real-time transmission of measuring points on the surface of the test specimen. The displacement sensor 24 is connected to the data acquisition instrument 21, and a ceramic extension rod 27 is installed at its tip. The ceramic extension rod 27 passes through the reserved hole 28 of the reflector plate and contacts the surface of the test specimen 5 to collect displacement changes of the measuring points in real time and transmit them to the measurement system. The data acquisition instrument 21 is connected to the controller 14 to achieve time synchronization between the control system and the measurement system, preventing deviations during the data acquisition process and subsequent data processing.
[0030] The combined mechanical and thermal testing device for test specimens under the specified temperature environment has an insulation sleeve 29 installed on the outer wall of cylinder I7 and cylinder II8, and a cooling water pipe 30 installed inside the insulation sleeve 29.
[0031] 1. Force loading device As attached Figure 3 Appendix Figure 4 As shown, the force load loading system uses hydraulic cylinders I7 and II8 for loading. The pressure is provided by the oil source. The servo valve receives the current signal (4~20mA) given by the control system and adjusts the pressure of hydraulic cylinders I7 and II8 in real time. Force sensors I22 and II23 send the force load value applied by the hydraulic cylinders in real time to realize closed-loop control.
[0032] A torque or force load is applied by the force load loading fixture 6. When applying the force load, the force load is applied by the hydraulic cylinders I7 and II8 at both ends, with hydraulic cylinders I7 and II8 simultaneously arranged on the upper side (see attached). Figure 3 This method can eliminate the bending moment caused by the lever arm. The schematic diagram is attached. Figure 6 As shown; when applying torque (see attached) Figure 4 One hydraulic cylinder I7 is arranged on the upper side, and another hydraulic cylinder II8 is arranged on the lower side to apply torque load.
[0033] When a pure torque is applied, its free-body diagram is shown in the attached figure. Figure 5 As shown, the force load is: F=F1+F2, and F1=-F2, the torque is: M=(F1-F2)×L, F1 and F2 are in opposite directions, the lever arm length of the loading fixture is L, and the force load is F=0 at this time.
[0034] According to the test requirements, if a pure tensile or compressive load is applied, the force load is as follows: Figure 6 As shown, the force load is: F=F1+F2, and F1=F2, and the torque is: M=(F1-F2)×L. The directions of F1 and F2 are the same, and the lever arm length of the loading fixture is L. At this time, the torque M=0.
[0035] When both force and torque need to be applied simultaneously, both methods can be used. With the first arrangement, the force is F = F1 + F2, where F1 ≠ F2, and the torque is M = (F1 - F2) × L. F1 and F2 are in opposite directions, meaning F1 is positive and F2 is negative. The lever arm length of the loading fixture is L. With the second arrangement, the force is F = F1 + F2, and the torque is M = (F1 - F2) × L. F1 and F2 are in the same direction, meaning they are either both positive or both negative. Generally, the first method is used when torque is the primary applied force, and the second method is used when force is the primary applied force.
[0036] 2. Heat loading device The heat loading system is used to apply temperature loads, and the main heating components are two sets of quartz lamps, one above the other. Thermocouples are attached to the surface of the test specimen, and the temperature collected by the thermocouples is fed back to the control system. The control system outputs a voltage signal (0~10V) to the power control cabinet in real time based on the target value and the measured temperature, and outputs power proportionally to achieve closed-loop regulation of the heat loading system.
[0037] To achieve precise control of the test specimen surface, the surface is divided into four regions: two regions in the upper half and two regions in the lower half. The heating temperatures of the two regions in the upper half and the two regions in the lower half can be designed to be equal. To ensure more uniform heating, the upper half is divided into two symmetrical zones, corresponding to the upper reflector 1011 and the upper group of quartz lamps 1111, designated as heating zone I 31 and heating zone II 32. The lower half is also divided into two symmetrical zones, corresponding to the lower reflector 1012 and the lower group of quartz lamps 1112, designated as heating zone III 33 and heating zone IV 34. Zoned control is used to heat the test specimen. The quartz lamps in different zones are installed on corresponding copper busbars I 25 and II 26, with each zone corresponding to two copper busbars. Therefore, there are four copper busbars in the upper half and four in the lower half, connected to the positive and negative terminals of the quartz lamps in that zone, respectively. The power control cabinet is connected to the copper busbars of the corresponding zones, achieving a closed-loop electrical system.
[0038] It should be noted that the quartz lamps are arranged symmetrically. For example, in the upper heating area, the left half corresponds to one zone and the right half corresponds to one zone, and the same applies to the lower heating area.
[0039] Each zone corresponds to a control channel in the control system. During the test, different target spectra can be set for different zones. Each control channel outputs a signal to the corresponding power control cabinet, which outputs power and the quartz lamp converts the electrical energy into radiant energy. The radiant energy is absorbed by the surface of the test piece, causing its surface temperature to rise. The temperature load of the zone is then monitored in real time by thermocouples and fed back to the control system, thereby realizing the application and control of the temperature load of that zone.
[0040] To prevent voltage from harming the human body and to prevent hazards caused by short circuits in equipment, quartz lamps should be mounted on the reflector using a special lamp clip. This prevents the quartz lamp cable connector from coming into contact with metal, which could cause a leakage hazard. When connecting the copper busbar to the reflector, an insulator should be used for the connection. That is, an insulator is installed on the reflector, and then the insulator is connected to the copper busbar.
[0041] To increase the absorption of surface energy of the test piece and reduce the dissipation of quartz lamp radiation energy, high-temperature resistant black paint was used to coat the surface of the test piece to increase the absorption rate of the test piece surface. High-temperature resistant white paint was used to coat the inside of the reflector, i.e. the side facing the test piece, to increase the reflectivity of the reflector. The outside of the reflector was coated with black paint to increase the emissivity of the reflector and accelerate the heat dissipation of the reflector.
[0042] 3. Temperature chamber system Temperature test chambers are mainly used to apply ambient temperature to simulate the launch environment temperature of a circular compartment, so as to reproduce the environment of the test piece during launch and transportation and ensure that the electronic components and thermal protection layer inside the test piece function normally under this environment.
[0043] The temperature test chamber is equipped with a personnel access door 38, a goods access door 39, an oil supply pipeline inlet 40, a cable inlet 41, and a signal line inlet 42. The personnel access door and the goods access door are also equipped with observation windows 43. Cable inlet 41 is for the passage of cables from power control cabinet I 18 and power control cabinet II 19. Signal line inlet 42 is for the passage of test cables or signal lines for strain gauges, displacement sensors 24, and thermocouples.
[0044] The temperature test chamber uses a vehicle test chamber (model: WTH1000D) with an internal space of 8×6×6m (length×width×height). The front is the chamber door for product and personnel access, and the rear is the air duct. See the attached diagram for a detailed layout. Figure 30 .
[0045] The temperature sensor 118 of the temperature test chamber is placed at the air outlet 114 to determine the temperature at the air outlet of the temperature test chamber. The temperature test chamber controller determines the power of the refrigeration unit and auxiliary heating based on the temperature feedback from the temperature sensor 118.
[0046] The lower end of the air duct 112 is the air inlet 113, through which the air in the temperature test chamber enters the air duct. When the temperature test chamber needs to provide a low temperature environment, the air in the chamber enters the air duct from the air inlet 113, and then exchanges heat with the refrigerant from the refrigeration unit in the heat exchanger 115 to cool the air. The cooled air passes through the electric heater 116 and then returns to the temperature test chamber through the air outlet 114. At this time, the heater does not work.
[0047] When the temperature test chamber provides a high-temperature environment, the air inside the chamber enters the air duct 112 through the air inlet 113, and then exchanges heat with the refrigerant from the refrigeration unit in the heat exchanger 115, which raises the temperature of the air. The heated air passes through the electric heater 116 and returns to the temperature test chamber through the air outlet 114. When the refrigerant in the heat exchanger 115 is insufficient to heat the air to the target temperature, the electric heater 116 should be used for auxiliary heating to make the air temperature inside the chamber reach the target value.
[0048] The fan 117 in the air duct 112 is located inside the air duct and close to the air outlet. Its function is to provide power for the air circulation inside the temperature test chamber.
[0049] Working principle: The industrial control computer 119 is connected to the refrigeration unit 120 of the refrigeration system to control the heat exchange of the refrigeration system; the refrigeration unit 120 of the refrigeration system is connected to the heat exchanger 115 to regulate the air temperature in the temperature test chamber; the industrial control computer 119, the power supply cabinet 121, and the electric heater 116 are connected in sequence to output corresponding heat when the heating capacity of the refrigeration system is insufficient, so as to ensure that the temperature inside the chamber reaches the required level; the temperature sensor 118 is connected to the industrial control computer 119 to monitor and provide feedback on the temperature inside the temperature chamber, thereby realizing closed-loop control of the temperature inside the test chamber; the industrial control computer 119 is connected to the fan 117 to realize air circulation inside the temperature chamber.
[0050] 4. Cooling system and protective measures The industrial control computer 119, refrigeration unit 120, power supply cabinet 121, control host computer 13, controller 14, oil source 17, power control cabinet I 18, power control cabinet II 19, measurement host computer 20, and data acquisition instrument 21 are placed outside the temperature test chamber for easy operation by personnel.
[0051] The refrigeration unit 120 and the power cabinet 121 are respectively connected to the heat exchanger 115 and the electric heater 116 inside the temperature test chamber through the pipes and cables on the back side of the chamber.
[0052] Since the combined force and heat test is conducted in a high / low temperature environment, the impact of temperature on cables, especially on components such as oil sources and displacement sensors, needs to be taken into account, and corresponding insulation measures are required.
[0053] Test cables or signal lines are connected to sensors (strain gauges, displacement sensors, thermocouples) through signal line inlets. The corresponding signal line of the sensor used for measurement on the other side is connected to the data acquisition unit 21, while the signal line of the sensor corresponding to the control channel is connected to the controller 14. The resistance of the signal lines changes under different temperature conditions, thus affecting the measurement results. Therefore, the cables need to be covered with heat-insulating sleeves, and high-temperature resistant tape should be wrapped around both ends of the sleeves to minimize heat exchange.
[0054] The oil pipe of oil source 17 connects to servo valve I 15 and servo valve II 16 inside the tank via the oil source pipeline inlet. Because the dynamic viscosity of hydraulic oil changes at different temperatures, the control parameter adjustment effect of the control system weakens; therefore, the hydraulic oil needs to operate at a relatively stable temperature. This system's cylinder surface is designed with a dedicated cooling system. (See attached...) Figure 24 As shown, an insulation sleeve 29 is installed close to the outer wall of the oil cylinder, and a cooling water pipe 30 is embedded inside the insulation sleeve 29. During the test, cooling water is circulated in the cooling water pipe 30 to absorb the heat conducted by the temperature test chamber and the heat generated by the oil cylinder during the test, so as to ensure that the oil temperature of the oil cylinder is stable during operation.
[0055] Displacement sensor 24 is a wide-temperature-range displacement sensor. It is mounted on support frame 37, and a ceramic extension rod 27 is installed at its front end. In use, the ceramic extension rod 27 passes through the reflector and contacts the surface of the test piece 5, as shown in the attached diagram. Figure 26 As shown; the location of the perforation, i.e., the reserved hole 28, on the reflector is shown in the appendix. Figure 19 As shown.
[0056] When arranging the cables inside the test piece, the cables can be routed through the through holes on the fixed base plate 4 of the test piece to ensure that the cables at the measuring points are unobstructed.
[0057] 5. Control and Measurement System The control system is used to control temperature and force loads. Target temperature and force load spectra are set in the host computer. The system adjusts the output signal in real time based on data from force sensors and thermocouples, as well as PID parameters, to achieve closed-loop control. The control system can achieve a temperature and force load control accuracy of 2%.
[0058] As attached Figure 27 As shown: The force loading system and the heat loading system control the host computer to set the target temperature spectrum and the target force load spectrum, and transmit the target spectrum to the control system via Ethernet communication protocol. First, the control system sends a 4-20mA signal to the servo valve to control its opening. To ensure a safety margin during static loading, the oil source pressure is manually controlled. The oil source is connected to the servo valve, which is connected to the oil cylinder. A force sensor installed at the front end of the oil cylinder provides real-time feedback of the force load value to the control system, thus achieving closed-loop control of the force load. Second, the control system sends a 0-10V signal to the power control cabinet and outputs power proportionally to the quartz lamp, causing the quartz lamp to radiate energy onto the surface of the test piece. The temperature is then fed back to the control system in real-time by a K-type thermocouple attached to the surface of the test piece, thus achieving closed-loop control of the heat loading system.
[0059] A time synchronization line is set between the control system and the measurement system to achieve time synchronization between the two systems and prevent deviations from occurring during data acquisition and subsequent data processing.
[0060] The measurement system is mainly used to collect temperature, strain, and displacement data. Thermocouples and strain gauges are attached to the surface of the test specimen as required, and the deformation and temperature changes of the test specimen surface are fed back to the measurement system in real time via signal lines. The data is then visualized and saved in real time on the host computer of the measurement system via Ethernet communication protocol.
[0061] To prevent temperature from affecting the displacement sensor, a ceramic extension rod is installed at the tip of the displacement sensor. The ceramic extension rod passes through the reserved hole of the reflector and rests on the surface of the test piece. The displacement change of the measuring point is collected in real time through the signal line at the other end and transmitted to the measurement system. The data is visualized and saved in real time in the measurement host computer through the IP protocol.
[0062] Type K thermocouples are used for temperature measurement. If the test piece is made of non-metallic material, it is bonded internally with high-temperature resistant tape or organic adhesive. When the temperature is above 400℃, inorganic adhesive is used. If the test piece surface is metallic, it can be welded or fixed by drilling holes and installing ceramic bolts.
[0063] When measuring strain, select room temperature strain gauges, medium temperature strain gauges, or high temperature strain gauges according to the loading temperature, and connect them in a 1 / 4 bridge manner.
[0064] The displacement sensor uses a wide temperature range to prevent inaccurate data or sensor failure due to temperature.
[0065] The controller 14 is model PXIe-1071, from a US company, company name: NI; the data acquisition instrument 21 is model DH3820N, from a manufacturing company, company name: Donghua Testing.
[0066] Specific experimental steps: 1. Connection of the test apparatus (1) Connection of force loading device The support frame 212 is connected to the cylinder fixing base 9. The cylinder fixing base 9 is connected to the cylinder II 8 via an adapter. The front end of the cylinder II 8 is connected to the force sensor II 23 and to the force load loading fixture 6 via the cylinder extension rod II 8 11, so as to apply the force load on the left side of the force load loading fixture 6.
[0067] The support frame 212 is connected to the cylinder fixing base 9. The cylinder fixing base 9 is connected to the cylinder I7 via an adapter. The front end of the cylinder I7 is connected to the force sensor I22 and connected to the force load loading fixture 6 via the cylinder extension rod I711, so as to apply the force load on the right side of the force load loading fixture 6.
[0068] The load loading fixture 6 is connected to the test piece 5 by bolts. The test piece 5 is then connected to the test piece fixing base plate 4 by bolts, then to the support plate 3, and then to the base 211, thereby fixing the test piece and applying the load.
[0069] (2) Connection of heating device The upper reflector 1011 and lower reflector 1012 are connected to insulator I 35 and insulator II 36 respectively via small screws. Insulator I 35 and insulator II 36 are then connected to copper busbar I 25 and copper busbar II 26 via small screws. Copper busbar I 25 and copper busbar II 26 are connected to the cables of the corresponding power control cabinet and simultaneously connected to the quartz lamps of the corresponding zones, thus achieving power connection for each heating zone and fixing of copper busbar I 25 and copper busbar II 26. The upper and lower sets of quartz lamps are connected to the upper reflector 1011 and lower reflector 1012 respectively via special lamp clips to fix the quartz lamps.
[0070] To ensure heating of the test zones and reduce heat convection between zones, partitions 1013 are installed between the zones and the intervals. The partitions 1013 are connected to the reflector by bolts. The reflector 10 is connected to the support leg 12, and the support leg 12 is placed on the support plate 3 (adjusting the support leg can adjust the height of the reflector). This achieves the connection and fixation of the reflector.
[0071] (3) Connection of temperature test chamber Both the force loading device and the heat loading device are placed in the temperature test chamber. In order to achieve temperature control in the temperature test chamber, the target temperature is set by the industrial control computer. The heat exchanger, electric heater, fan and temperature sensor are arranged in sequence from the air inlet to the air outlet in the air duct.
[0072] 2. Implementation of the experiment (1) Installation before the test Thermocouples and strain gauges are attached to the internal and external measuring points of the test specimen and connected to the measurement system. The signals from the installed thermocouples and strain gauges are confirmed to be normal. Black paint is sprayed onto the surface of the test specimen. The test platform must be erected before the test, and the test specimen is installed and secured. The quartz lamp is mounted on the reflector, and the quartz lamp leads are connected to the copper busbar. The corresponding reflectors are connected according to the heating area, and installation must be carried out in sequence. The test specimen is now ready for testing.
[0073] (2) Preparation before the experiment Connect the control point thermocouple to the control system and check if the thermocouple signal is normal and if the control point thermocouple is firmly attached. If loose, reinstall it. After installing the reflector and other heat loading devices, install the force loading fixture. Install the hydraulic cylinder, force sensor, and other force loading devices. Connect the force sensor to the force control system, set the relevant parameters, and confirm that the sensor signal is normal. Install the displacement sensor to the designated position as required. If the displacement sensor cannot be directly installed, fix the extension rod in the designated position and connect the other end to the displacement sensor. Connect the displacement sensor to the measurement system, push the displacement sensor, and confirm that the data is normal. Limit the oil source pressure to ensure that the force load does not exceed the limit during the test.
[0074] (3) Loading before the pre-test Before loading begins, the data should be zeroed out. The static load should be less than 30% of the formal test load, and the temperature load should be less than 30% of the formal load. Adjust the control parameters until the fitting error between the measured curve and the target curve meets the requirements. Confirm the control parameters based on the pre-test results.
[0075] (4) Formal test temperature loading After confirming that the test specimens and testing fixtures are installed correctly, close the temperature test chamber door. The temperature test chamber will operate under the set control temperature curve until the temperature at all measuring points reaches the target value. After the insulation period, zero the measurement system data and check whether the force load output curve is normal, whether the measurement system is working properly, whether the displacement sensor signal is normal, whether the temperature output curve is normal, whether the DC current cabinet is turned on, and whether the thermocouple signal is normal. Confirm the test control curve, and the control system will start outputting signals. Load the test according to the test curve. If any abnormal signal occurs during the test, stop the test immediately and record it. After the loading is completed, the control system will stop outputting signals, and the measurement system will continue to acquire data until the strain curve and displacement curve fluctuations are small, at which point the acquisition will end; temperature acquisition will end 300 seconds after the temperature loading ends.
[0076] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only for the purpose of helping to understand the method and core ideas of the present invention. The above descriptions are only preferred embodiments of the present invention. It should be noted that due to the limitations of textual expression, and the objective existence of infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the concept and technical solution of the present invention to other occasions without modification, should all be considered within the scope of protection of the present invention.
Claims
1. A combined mechanical and thermal testing apparatus for test specimens under temperature conditions, characterized in that, The test chamber includes a temperature test chamber (1), a test stand (2) installed inside the temperature test chamber (1), a support plate (3), a test piece fixing base plate (4), and a cylindrical test piece (5) connected sequentially from bottom to top on the test stand (2). It also includes a force loading device, a heat loading device, and a control and measurement system, wherein: The test bench (2) includes a base (211) and a support frame (212), and the support plate (3) is connected to the base (211); The force loading device includes a force load loading fixture (6), a hydraulic cylinder I (7), a hydraulic cylinder II (8), and a hydraulic cylinder fixing base (9). The hydraulic cylinder I (7) and the hydraulic cylinder II (8) are located above or above and below the force load loading fixture (6). The top of the test piece (5) is connected to the lower end face of the force load loading fixture (6). The heat loading device includes a hollow cylindrical reflector (10) with openings at the top and bottom. The reflector (10) is located on the outside of the test piece (5). A quartz lamp (11) is installed on the inner wall of the reflector in the gap between the test piece (5) and the reflector (10). The quartz lamp (11) consists of two sets, one above the other. A support leg (12) is installed below the reflector (10). The control and measurement system includes a control host computer (13), a controller (14), servo valve I (15), servo valve II (16), an oil source (17), a power control cabinet I (18), a power control cabinet II (19), a measurement host computer (20), a data acquisition instrument (21), a force sensor I (22), a force sensor II (23), strain gauges, a displacement sensor (24), and a K-type thermocouple.
2. The combined mechanical and thermal testing apparatus for test specimens under temperature conditions according to claim 1, characterized in that, The hydraulic cylinders I (7) and II (8) are located on both sides above the force load loading fixture (6). The bottom of the hydraulic cylinders I (7) and II (8) is connected to the lower top of the support frame (212) through the hydraulic cylinder fixing base (9).
3. The combined mechanical and thermal testing apparatus for test specimens under temperature conditions according to claim 1, characterized in that, The hydraulic cylinders I (7) and II (8) are respectively positioned above and below the force load loading fixture (6). The bottoms of the hydraulic cylinders I (7) and II (8) are connected to the lower top of the support frame (212) and the base (211) respectively through the hydraulic cylinder fixing base (9).
4. The combined mechanical and thermal testing apparatus for test specimens under temperature conditions according to claim 1, characterized in that, The reflector (10) includes an upper reflector (1011) and a lower reflector (1012) connected vertically. The lower end of the upper reflector (1011) and the upper end of the lower reflector (1012) both extend outward to form flange ends. An annular partition (1013) is provided inward at the lower end of the upper reflector (1011), and a connecting piece (1014) for connecting the support leg (12) extends outward at the lower end of the lower reflector (1012).
5. The combined mechanical and thermal testing apparatus for test specimens under temperature conditions according to claim 1, characterized in that, The temperature test chamber (1) includes a chamber body (111), and an air duct (112) is provided inside the chamber body (111). The lower end of the air duct (112) is an air inlet (113), and the upper end is an air outlet (114). A heat exchanger (115), an electric heater (116), a fan (117), and a temperature sensor (118) are arranged sequentially from the air inlet (113) to the air outlet (114) inside the air duct (112).
6. The combined mechanical and thermal testing apparatus for test specimens under temperature conditions according to claim 1, characterized in that, The host computer (13) is connected to the controller (14) for editing target spectra, transmitting monitoring commands and signal feedback display. The controller (14) is connected to servo valve I (15) and servo valve II (16) for controlling the opening of the servo valves to ensure stable loading of force loads. The oil source (17) is connected to servo valve I (15) and servo valve II (16) to ensure the supply of hydraulic oil. The piston rods of cylinder I (7) and cylinder II (8) are respectively provided with cylinder extension rod I (711) and cylinder extension rod II (811). Valve I (15), cylinder I (7), force sensor I (22), cylinder extension rod I (711), force load loading fixture (6) and test piece (5) are connected in sequence. II (16), cylinder II (8), force sensor II (23), cylinder extension rod II (811), force load loading fixture (6) and test piece (5) are connected in sequence to ensure that the cylinder applies force load stably. Force sensor I (22) and force sensor II (23) are connected to controller (14) to provide real-time feedback of force load data, thereby realizing closed-loop control of the force load device.
7. The combined mechanical and thermal testing apparatus for test specimens under temperature conditions according to claim 1, characterized in that, The controller (14) is connected to power control cabinet I (18) and power control cabinet II (19) to realize the power output and proportional control of the power control cabinet. Power control cabinet I (18) and power control cabinet II (19) are respectively connected to copper busbar I (25) and copper busbar II (26) through cables. Copper busbar I (25) and copper busbar II (26) are respectively connected to the upper and lower quartz lamps (11) through the cables of the quartz lamps to realize the heating of the surface of the test piece (5). The surface temperature of the test piece is transmitted to the controller (14) in real time through the K-type thermocouple pasted on the surface of the test piece (5) to achieve closed-loop temperature control.
8. The combined mechanical and thermal testing apparatus for test specimens under temperature conditions according to claim 1, characterized in that, The measurement host computer (20) is connected to the data acquisition instrument (21) to realize real-time data acquisition, visualization and storage. The strain gauge and K-type thermocouple are pasted on the surface of the test piece (5) and connected to the data acquisition instrument (21) to realize data acquisition and real-time transmission of the measuring points on the surface of the test piece. The displacement sensor (24) is connected to the data acquisition instrument (21) and a ceramic extension rod (27) is installed at its tip. The ceramic extension rod (27) passes through the reserved hole (28) of the reflector and contacts the surface of the test piece (5) to collect the displacement changes of the measuring points in real time and transmit them to the measurement system. The data acquisition instrument (21) is connected to the controller (14) to realize time synchronization between the control system and the measurement system and prevent deviations in the data acquisition process and subsequent data processing.
9. The combined mechanical and thermal testing apparatus for test specimens under temperature conditions according to claim 1, characterized in that, The outer walls of the oil cylinders I (7) and II (8) are provided with heat insulation sleeves (29), and the inside of the heat insulation sleeves (29) is provided with cooling water pipes (30).