System and method for testing thermal expansion coefficient of flexible substrate assembly under constant tension condition

Abstract

The invention provides a system and a method for testing a thermal expansion coefficient of a flexible substrate assembly under a constant tension condition. The system comprises a high-low temperature box, a loading strip, a dial indicator, a substrate connecting rope, a constant force counterweight structure, a test board and a tested flexible substrate, the high-low temperature box is placed on the test board, and the inner side of the high-low temperature box can adjust the temperature; a tested flexible substrate is placed in the high-low temperature box, one end of the tested flexible substrate is fixed in the high-low temperature box, and the other end is connected with a plurality of substrate connecting ropes; the substrate connecting rope extends outwards and penetrates through the outer side of the high-low temperature box; the constant-force counterweight structure is arranged on one side, corresponding to the substrate connecting rope, of the test board; the loading strips are fixedly connected to the substrate connecting rope and the constant force counterweight structure respectively, and the loading strips are elastically connected; a plurality of dial gauges are arranged and are respectively fixed on the test board, and the measuring ends of the dial gauges are connected to the loading strip close to the tested flexible substrate and are respectively used for measuring the horizontal movement distance of the loading strip. The device has the effects of testing the thermal expansion coefficient under the constant tension load of the flexible substrate and uniformly loading the tension.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of space flexible solar wing, and particularly relates to a system and method for testing thermal expansion coefficient of a flexible substrate assembly under constant tension. BACKGROUND

[0002] With the multi-function of spacecraft and the increase of load, the demand for solar wing power is increasing, and the volume and weight of traditional rigid / half-rigid solar array will also increase in proportion to the required power, which is difficult to meet the demand for high mass-specific power and volume-specific power of large power satellites, "one rocket multiple satellites" and the like, and the lightweight flexible solar cell wing has great advantages.

[0003] The flexible solar cell wing adopts a flexible substrate, which is generally in the form of a composite structure of polyimide film and glass cloth, polyimide film and glass fiber mesh. When used in orbit, in order to improve and ensure the flatness of the substrate and the fundamental frequency of the flexible solar wing, the flexible substrate needs to be tensioned, and the high-low temperature alternating environment in space will cause thermal deformation of the flexible substrate, which will seriously cause the battery pieces on the flexible substrate to be detached or broken, reducing the power supply capacity of the solar wing. In order to ensure the safety and reliability of the flexible solar wing in orbit, sufficient design guarantee and test verification need to be carried out on the ground.

[0004] Patent document CN116735651A discloses a thermal expansion coefficient tester, which comprises a detection part arranged on a rack, the detection part comprising a sensor; a sample placement part located below the detection part; a heating unit for heating the sample; a lifting mechanism linked with the heating unit; when the heating unit is located at a high position, the sample on the sample carrier is located inside the heating area of the heating unit; when the heating unit is located at a low position, the sample on the sample carrier is located outside the heating unit.

[0005] However, the detection object of patent document CN116735651A is mainly rigid material, and since the substrate is a flexible composite structure, the flexible substrate is not subjected to constant tension during the test, which may not be consistent with the in-orbit working condition, and the verification is not sufficient, which cannot effectively obtain the related parameters, and the design input may be deviated.

[0006] Therefore, the thermal expansion coefficient of the flexible substrate under constant tension load is tested, the loading tension is uniform, the test is effective, and actual parameters can be provided for design. Therefore, the present application designs a system and method for testing thermal expansion coefficient of a flexible substrate assembly under constant tension, which solves the above problems. SUMMARY

[0007] In view of the defects in the prior art, the purpose of the present application is to provide a system and method for testing thermal expansion coefficient of a flexible substrate assembly under constant tension.

[0008] The application provides a flexible substrate assembly thermal expansion coefficient testing system under constant tension, which comprises a high-low temperature box, loading bars, a dial gauge, substrate connecting ropes, a constant force counterweight structure, a testing table and a measured flexible substrate.

[0009] The high-low temperature box is placed on the testing table, and the inside of the high-low temperature box can be adjusted in temperature.

[0010] The measured flexible substrate is placed in the high-low temperature box, one end of which is fixed to the inside of the high-low temperature box, and the other end is connected to a plurality of substrate connecting ropes.

[0011] The substrate connecting ropes extend outward through the high-low temperature box.

[0012] The constant force counterweight structure is arranged on one side of the testing table corresponding to the substrate connecting ropes.

[0013] The loading bars are respectively fixedly connected to the substrate connecting ropes and the constant force counterweight structure, and are elastically connected between the loading bars.

[0014] The dial gauges are arranged on the testing table, and the measuring ends of the dial gauges are connected to the loading bars close to the measured flexible substrate, so as to respectively measure the horizontal movement distance of the loading bars.

[0015] Preferably, the constant force counterweight structure comprises a counterweight connecting rope and a tension counterweight.

[0016] The counterweight connecting rope is connected to the loading bar away from the measured flexible substrate.

[0017] The tension counterweight is connected to one end of the counterweight connecting rope opposite to the loading bar.

[0018] The counterweight connecting rope is bent and vertically extended along the pulley assembly, and the tension counterweight is hung.

[0019] Preferably, the pulley assembly comprises a steering pulley and a pulley support.

[0020] The steering pulley is installed on the top of the pulley support and can rotate around the rotation shaft.

[0021] The counterweight connecting rope is bent and vertically downward extended along the steering pulley.

[0022] Preferably, the two loading bars are elastically connected by a plurality of tension springs.

[0023] Preferably, the high-low temperature box is provided with wire holes for horizontally penetrating the plurality of substrate connecting ropes.

[0024] Preferably, the dial gauges are symmetrically arranged on both sides of the loading bars.

[0025] Preferably, the high-low temperature box is provided with a glass observation window.

[0026] Preferably, the substrate connecting rope is made of carbon fiber rope.

[0027] According to the present invention, a method for testing the coefficient of thermal expansion of a flexible substrate assembly under constant tension is provided, which employs the aforementioned testing system for the coefficient of thermal expansion of a flexible substrate assembly under constant tension, and includes the following steps:

[0028] Step S1: Select an appropriate tension counterweight according to the preset value to apply tension force to the flexible substrate, and fix the position of the dial indicator;

[0029] Step S2: Apply temperature to the flexible substrate under test using a high and low temperature chamber, and measure the displacement values ​​of two dial gauges at different temperatures;

[0030] Step S3: The coefficient of thermal expansion of the flexible substrate can be obtained through calculation. The formula for calculating the coefficient of thermal expansion of the flexible substrate is as follows:

[0031] α=((D21-D11)+(D22-D12)) / (2×L×(T2-T1))

[0032] Where T1 represents the first temperature, D11 represents the first thousandths value at temperature T1, D12 represents the second thousandths value at temperature T1, T2 represents the second temperature, D21 represents the first thousandths value at temperature T2, D22 represents the second thousandths value at temperature T2, L represents the length of the flexible substrate being measured, and α represents the coefficient of thermal expansion of the flexible substrate.

[0033] According to the present invention, a thermal cycling test of a flexible substrate is provided, using the thermal expansion coefficient testing system of the flexible substrate assembly under constant tension.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The device of the present invention can accurately measure the thermal expansion coefficient of flexible substrate components, providing practical parameters for design.

[0036] 2. The device of the present invention applies uniform loading tension to the flexible substrate, and the testing method is simple and effective.

[0037] 3. The device of the present invention can be used for thermal cycling tests of flexible substrates under constant tension load, which is more compatible with actual on-orbit working conditions. Attached Figure Description

[0038] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0039] Figure 1 This is a schematic diagram of the overall system for testing the thermal expansion coefficient of a flexible substrate assembly under constant tension conditions according to the present invention.

[0040] Figure 2 This is a partial schematic diagram of the tension loading and displacement testing behind the concealed high and low temperature chamber in this invention.

[0041] The diagram shows: 1. High and low temperature chamber; 2. Loading bar; 3. Tension spring; 4. Dial indicator; 5. Connecting rope; 6. Steering pulley; 7. Pulley bracket; 8. Tension counterweight; 9. Counterweight connecting rope; 10. Test bench; 11. Flexible substrate under test. Detailed Implementation

[0042] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0043] like Figure 1 , Figure 2 As shown, a thermal expansion coefficient testing system for a flexible substrate assembly under constant tension includes a high and low temperature chamber 1, a loading bar 2, a tension spring 3, a dial indicator 4, a substrate connecting rope 5, a pulley assembly, a constant force counterweight structure, a test platform 10, and a flexible substrate 11 to be tested.

[0044] The high and low temperature chamber 1 is placed on the test bench 10. The temperature inside the high and low temperature chamber 1 is adjustable. Temperature measuring thermocouples and cooling equipment are arranged inside the high and low temperature chamber 1. The power of the heating / cooling equipment of the high and low temperature chamber 1 is adjusted or turned on or off according to the difference between the temperature measured by the thermocouples and the target temperature, so as to achieve the function of temperature regulation.

[0045] High and low temperature chamber 1 with a glass observation window;

[0046] The flexible substrate 11 to be tested is placed in the high and low temperature chamber 1, with one end fixed inside the high and low temperature chamber 1 and the other end connected to multiple substrate connecting ropes 5.

[0047] The substrate connecting rope 5 extends outward and passes through the outside of the high and low temperature chamber 1;

[0048] The substrate connecting rope 5 is made of carbon fiber rope with a low coefficient of thermal expansion.

[0049] The high and low temperature chamber 1 has wire holes for multiple base plate connecting ropes 5 to be threaded horizontally.

[0050] There are two loading bars 2, which are connected by multiple tension springs 3. Together with the loading bars at both ends, they form an elastic loading, which uniformly converts the concentrated counterweight force into multi-point tension of the substrate.

[0051] One side of the loading bar 2 is connected to multiple base plate connecting ropes 5, and the other side of the loading bar is connected to the constant force counterweight structure.

[0052] The constant force counterweight structure includes a counterweight connecting rope 9 and a tension counterweight 8;

[0053] The counterweight connecting rope 9 is connected to the loading bar 2 on the side away from the flexible substrate 11 being tested;

[0054] The counterweight connecting rope 9 bends vertically along the pulley assembly and suspends the tension counterweight 8, converting the constant vertical gravity of the tension counterweight 8 into a constant horizontal tension on the flexible substrate 11 under test.

[0055] The pulley assembly includes a steering pulley 6 and a pulley bracket 7;

[0056] The steering pulley 6 is mounted on top of the pulley bracket 7 and can rotate circumferentially around the rotation axis to reduce frictional resistance and avoid affecting the tension.

[0057] The counterweight connecting rope 9 bends and extends vertically downwards along the steering pulley 6.

[0058] The dial gauge 4 has multiple settings, and in this embodiment, the dial gauge 4 is symmetrically set on both sides of the loading bar 2;

[0059] The dial indicator 4 is fixed to the test stage 10. The measuring end of the dial indicator 4 is connected to the loading strip 2 on the side near the flexible substrate 11 under test, and measures the horizontal movement distance of the loading strip 2.

[0060] like Figure 1 , Figure 2 As shown, this invention consists of a high-low temperature chamber 1 placed on a test bench 10. The flexible substrate 11 to be tested is placed inside the high-low temperature chamber 1. The temperature of the flexible substrate 11 is adjusted by the high-low temperature chamber 1. Four substrate connecting ropes 5 are evenly arranged and connected to the loading strips 2. The use of carbon fiber ropes with a low coefficient of thermal expansion does not affect the accuracy of measuring the thermal expansion or contraction of the flexible substrate 11. The two loading strips 2 are elastically connected by four tension springs 3, ensuring that there is a certain degree of deformation even if there are certain manufacturing errors in the substrate connecting ropes 5 and the loading strips 2. Adaptability ensures uniform loading force; the pulley bracket 7 has three brackets, placed at a certain distance from the test platform 10, and the counterweight connecting rope 9 is connected to the center of the loading bar 2. After extending horizontally, it extends vertically downward around the steering pulley 6, keeping the tension counterweight 8 in a suspended state, thereby applying a stable constant force to the flexible substrate 11 under test; the dial indicator 4 is set on both sides of the loading bar 2. When the loading bar 2 is slightly tilted, the average value on both sides is more accurate. The flexible substrate 11 under test expands and contracts under thermal changes, and the change distance is read by the dial indicator 4.

[0061] The present invention also provides a thermal cycling test for a flexible substrate, using the above-mentioned thermal expansion coefficient testing system for a flexible substrate assembly under constant tension.

[0062] This invention also provides a method for testing the coefficient of thermal expansion of a flexible substrate assembly under constant tension, comprising the following steps:

[0063] Step S1: Select the appropriate tension counterweight 8 according to the preset value to apply tension force to the flexible substrate, and fix the position of dial gauge 4.

[0064] Step S2: Apply temperature to the flexible substrate 11 under test using a high and low temperature chamber 1, and measure the displacement values ​​of the two dial gauges 4 at different temperatures.

[0065] Step S3: The coefficient of thermal expansion of the flexible substrate can be obtained through calculation. At temperature T1, the readings of the two dial gauges 4 are D11 and D12 respectively; at temperature T2, the readings of the two dial gauges 4 are D21 and D22 respectively. The length of the flexible substrate 11 being measured is L, and α represents the coefficient of thermal expansion of the flexible substrate. The formula for calculating the coefficient of thermal expansion of the flexible substrate is:

[0066] α=D21-D11+D22-D12 / 2×L×T2-T1.

[0067] This invention provides a device for testing the coefficient of thermal expansion of flexible substrates under constant tension load. The loading tension is uniform, and the test is simple and effective, providing practical parameters for design. It can also be used for thermal cycling tests of flexible substrates, better matching the actual on-orbit operating conditions of flexible substrates.

[0068] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0069] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A system for testing the coefficient of thermal expansion of a flexible substrate assembly under constant tension, characterized in that, Includes a high and low temperature chamber (1), a loading bar (2), a dial indicator (4), a substrate connecting rope (5), a constant force counterweight structure, a test bench (10), and a flexible substrate to be tested (11); The high and low temperature chamber (1) is placed on the test bench (10), and the temperature inside the high and low temperature chamber (1) is adjustable; The flexible substrate (11) to be tested is placed in a high and low temperature chamber (1), with one end fixed to the high and low temperature chamber (1) and the other end connected to multiple substrate connecting ropes (5). Multiple substrate connecting ropes (5) extend outward and pass through the outside of the high and low temperature chamber (1); A constant force counterweight structure is set on one side of the test bench (10) corresponding to the base plate connecting rope (5); Multiple loading bars (2) are set side by side, and the loading bars (2) are flexibly connected to each other; The loading bars (2) located at both ends are fixedly connected to the base plate connecting rope (5) and the constant force counterweight structure, respectively; Multiple dial indicators (4) are set up and fixed to the test bench (10). The measuring end of the dial indicator (4) is connected to the loading bar (2) near the flexible substrate (11) under test, and the horizontal movement distance of the loading bar (2) is measured respectively.

2. The thermal expansion coefficient testing system for flexible substrate components under constant tension as described in claim 1 is characterized in that, The constant force counterweight structure includes a counterweight connecting rope (9) and a tension counterweight (8); The counterweight connecting rope (9) is connected to the loading bar (2) on the side away from the flexible substrate (11) being tested; The tension counterweight (8) is connected to one end of the counterweight connecting rope (9) relative to the loading bar (2); The counterweight connecting rope (9) extends vertically along the pulley assembly and suspends the tension counterweight (8).

3. The thermal expansion coefficient testing system for flexible substrate components under constant tension according to claim 2, characterized in that, The pulley assembly includes a steering pulley (6) and a pulley bracket (7); The steering pulley (6) is mounted on top of the pulley bracket (7) and can rotate around the rotation axis; The counterweight connecting rope (9) bends and extends vertically downward along the steering pulley (6).

4. The thermal expansion coefficient testing system for flexible substrate components under constant tension according to claim 1, characterized in that, The two loading bars (2) are elastically connected by multiple tension springs (3).

5. The thermal expansion coefficient testing system for flexible substrate components under constant tension according to claim 1, characterized in that, The high and low temperature chamber (1) has wire holes for multiple substrate connecting ropes (5) to be threaded horizontally.

6. The thermal expansion coefficient testing system for flexible substrate components under constant tension according to claim 1, characterized in that, The dial gauge (4) is symmetrically set on both sides of the loading bar (2).

7. The thermal expansion coefficient testing system for flexible substrate components under constant tension according to claim 1, characterized in that, The high and low temperature chamber (1) is equipped with a glass observation window.

8. The thermal expansion coefficient testing system for flexible substrate components under constant tension according to claim 1, characterized in that, The substrate connecting rope (5) is made of carbon fiber.

9. A method for testing the coefficient of thermal expansion of a flexible substrate assembly under constant tension, using the coefficient of thermal expansion testing system for a flexible substrate assembly under constant tension as described in any one of claims 1-8, characterized in that the steps include... include: Step S1: Select a suitable tension counterweight (8) according to the preset value to apply tension force to the flexible substrate and fix the position of the dial indicator (4); Step S2: Apply temperature to the flexible substrate (11) under test using a high and low temperature chamber (1), and measure the displacement values ​​of two dial gauges (4) at different temperatures; Step S3: The coefficient of thermal expansion of the flexible substrate can be obtained through calculation. The formula for calculating the coefficient of thermal expansion of the flexible substrate is as follows: α=((D21-D11)+(D22-D12)) / (2×L×(T2-T1)) Where T1 represents the first temperature, D11 represents the reading of the first dial gauge (4) at temperature T1, D12 represents the reading of the second dial gauge (4) at temperature T1, T2 represents the second temperature, D21 represents the reading of the first dial gauge (4) at temperature T2, D22 represents the reading of the second dial gauge (4) at temperature T2, L represents the length of the flexible substrate (11) being measured, and α represents the coefficient of thermal expansion of the flexible substrate.

10. A thermal cycling test for a flexible substrate, using the thermal expansion coefficient testing system for a flexible substrate assembly under constant tension as described in any one of claims 1-8.

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