Compression strength testing method for flexible aerogel product

Abstract

The invention discloses a compression strength testing method for a flexible aerogel product. The compression strength testing method comprises the following steps: preparing two square samples; applying a first pressure to the first sample, measuring the deformation generated by the first sample, and converting the deformation into the hardness of the sample; querying a hardness-compression strength comparison table to obtain pressure required for flattening the sample, and recording the pressure as second pressure; pressing the second sample by adopting second pressure intensity, and measuring the thickness of the flattened second sample to obtain D1; calculating the compression strength value point thickness D2 and the compression test cut-off displacement D3 according to the D1; pressing the thickness of the second sample to D3; if the sample still has no yield point after being pressed to D3, calculating the compression strength of the sample according to a force value when the sample is pressed to D2; and if the sample is pressed to D3 to have a yield point, calculating the compression strength of the sample according to a yield point force value. According to the application, the influence of human factors is avoided, and the compression strength of the flexible felt can be simply, efficiently, truly and reliably tested.

Description

Technical Field

[0001] The present application relates to the technical field of material testing, and in particular to a compression strength testing method for flexible aerogel products. Background Art

[0002] Flexible aerogels have been widely used as industrial pipelines and building insulation materials. Their compressive strength is a key indicator to measure whether the product has good working performance under pressure, and it is involved in many aerogel test standards. Since most flexible aerogel felts do not have a yield point, that is, they do not produce rigid damage when under pressure, but the thickness decreases under the action of pressure, and the force of the pressing plate is constantly increasing. Therefore, the force of the sample being compressed and deformed to a certain proportion is generally taken as the maximum load for calculating the compressive strength. However, due to the size limitation of the supercritical drying equipment in the preparation process, aerogel felts are usually rolled into rolls for drying, which leads to the natural curling of aerogel felts. In addition, when the test value involves deformation, and the deformation is often determined by the displacement of the pressing plate after the sample is flattened, it is necessary to ensure that the zero point position of the deformation is the same starting point for each test. Before starting the compression test, ensuring that the aerogel product is flattened as little as possible under pressure becomes a key issue in solving the aerogel compression test.

[0003] Existing methods often specify a fixed force or pressure to flatten the sample before testing. However, with the development of aerogel manufacturing technology and the manufacturers' pursuit of thermal insulation performance, the design density of flexible aerogel felt is increasing. Without a significant increase in thickness, the strength and hardness of the aerogel have increased. This directly leads to the previous method being unable to flatten the sample under the action of the specified force or pressure, resulting in many samples being unable to be tested according to the standard method, and if the standard is revised to increase the force or pressure alone, it will be difficult to apply to products with low density and soft texture. This brings many problems and inconveniences to the compression strength test of aerogels.

[0004] In addition, previous methods made it difficult to determine the zero point of displacement by finding the intersection of the tangent of the elastic segment with the coordinate axis for samples such as flexible aerogel felt that have no yield point, whose force-displacement curve is close to an exponential function and have no obvious elastic deformation stage. This resulted in the point selection method being greatly affected by human factors and failing to truly reflect the most accurate and reliable compression strength value of the sample.

[0005] Some laboratories also apply the compression method of piezoelectric ceramics to aerogel products. The biggest difference between this method and our commonly used test method for the compression strength of flexible aerogel felt is that it is aimed at hard materials and the sample size is only 1 / 400 of the conventional method. Even if the hardness can meet the development and changes of aerogels, aerogel products often have great heterogeneity. Using very small samples for testing cannot reflect the overall performance of the samples. If the error is reduced by increasing the number of tests, the workload will increase, so this test method is not suitable for flexible aerogel products.

[0006] The current test method basically adopts a one-size-fits-all approach, lacking methods and equipment to set parameters for aerogel products of different hardness separately, making the method difficult to apply. In addition, the method of using the elastic segment tangent to make the displacement zero point will introduce human errors, causing the test value to be distorted. Summary of the invention

[0007] The present application provides a method for testing the compressive strength of a flexible aerogel product, which has the advantages of being able to test the compressive strength of an aerogel product, avoiding the influence of human factors, and being able to test the compressive strength of a flexible felt simply, efficiently, truly and reliably.

[0008] The above-mentioned object of the present application is achieved through the following technical solution: A method for testing the compressive strength of a flexible aerogel product, comprising the following steps: S1: Prepare 2 square specimens; S2: applying a first pressure to the first sample, measuring the maximum deformation of the first sample and converting it into the hardness of the sample; S3: According to the hardness of the sample obtained in step S2, the hardness-compression strength comparison table is searched to obtain the pressure required to flatten the sample, which is recorded as the second pressure; S4: pressing a second sample with a second pressure, and measuring the thickness of the flattened second sample to obtain a thickness D1 of the sample; S5: Calculate the sample compression strength value point thickness D2 according to the sample thickness D1, and calculate the compression test cut-off displacement D3 according to the sample compression strength value point thickness D2; S6: Press the thickness of the second sample to D3 at a set rate; If the sample still has no yield point after being compressed to D3, the compressive strength of the sample is calculated based on the force value when the sample is compressed to D2; If the sample shows a yield point when compressed to D3, the compressive strength of the sample is calculated using the yield point force value.

[0009] Further, the hardness-compression strength comparison table is obtained by the following method: The hardness and compression strength of several existing flexible aerogel products were tested to obtain the corresponding relationship between the hardness and compression strength of the samples; A flattening test was performed on several existing flexible aerogel products to obtain the compressive strength of the samples when they were flattened; Draw a scatter plot of sample hardness-compression strength and use curve fitting Plot the specimen hardness versus compressive strength when flattened and use a curve fit.

[0010] Further, the steps S2 and S4 are implemented by a thickness testing device for flexible aerogel products, and the thickness testing device for flexible aerogel products comprises a base, an upper platen, and a hardness tester for flexible aerogel; The flexible aerogel hardness tester comprises: An outer cylinder, wherein a counterweight stabilizing plate is disposed on the outer side of the bottom of the outer cylinder, and the counterweight stabilizing plate is mounted on the base; An inner cylinder, wherein the contents are arranged in the outer cylinder, and the top of the inner cylinder is fixedly connected to the top of the outer cylinder; A pressure rod, wherein a flat plate is provided at the top of the pressure rod, and the flat plate is used to be connected to the bottom of the upper pressure plate. The pressure rod passes through the inner cylinder and a pressure head is provided at the bottom of the pressure rod; A first spring, wherein the first spring is arranged between the pressure rod and the inner cylinder, and two ends of the first spring are respectively fixedly connected to the top of the inner cylinder and the pressure head; Two strain gauges, which are respectively arranged on the upper side of the inner cylinder and at the junction of the pressure head and the spring; and a display calculation unit connected to the two strain gauges for calculating and displaying the displacement detected by the strain gauges.

[0011] When executing step S2, the hardness tester for the flexible aerogel is placed between the base and the upper pressing plate, and when executing step S4, the hardness tester for the flexible aerogel is taken out from between the base and the upper pressing plate.

[0012] Furthermore, the working surface of the pressure head is a spherical surface, and the pressure head is provided with a first limiting step whose diameter is larger than the diameter of the inner cylinder; the pressure rod is provided with a second limiting step at a position above the outer cylinder, and a second spring is provided between the outer cylinder and the second limiting step.

[0013] Furthermore, the display and calculation unit is arranged on the surface of the outer cylinder, the strain gauge is connected to the display and calculation unit through a wire, and grooves are provided on the inner cylinder and the outer cylinder for wiring of the wire.

[0014] Furthermore, the base includes a ball seat and a lower pressure plate, the ball seat is provided with a spherical groove, and the bottom of the lower pressure plate is provided with a protrusion that cooperates with the spherical groove.

[0015] Furthermore, the lower pressing plate is provided with at least three non-collinear laser rangefinders, the laser rangefinders are embedded in the lower pressing plate and the upper surface of the laser rangefinders is not higher than the upper surface of the lower pressing plate, and the bottom of the upper pressing plate is provided with a reflective film corresponding to the laser rangefinders one by one.

[0016] Furthermore, the hardness tester for flexible aerogel also includes an electronic universal testing machine, the pressure of the pressure rod in the hardness tester for flexible aerogel is provided by the electronic universal testing machine, and the upper pressure plate is provided with a connecting rod with a pin hole for connecting with the crossbeam of the electronic universal testing machine.

[0017] Furthermore, in step S2, the deformation of the first sample is obtained by a strain gauge; in step S4, the thickness of the second sample is measured and obtained by reading a laser rangefinder.

[0018] In summary, the beneficial effects of this application are: 1. This application scheme has a wide range of applications and has no restrictions on flexible aerogel products. It can be used to test the thickness of different flexible aerogel products; 2. This application scheme uses a flexible aerogel hardness tester to test the hardness of the product. By querying the hardness-compression strength correspondence table obtained in advance verification test, the initial pressure value required for product testing can be found, and how to set the initial pressure to achieve the effect of flattening the test sample without over-compression can be solved in a scientific and effective way, thereby obtaining a more accurate measurement result; 3. In the test of this application scheme, a laser rangefinder is used to test the distance between the flat plates as the sample thickness, so as to avoid the error of manual reading and reduce the influence of the wrinkles on the surface of the flexible felt on the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the structure of a hardness tester for a flexible aerogel in one embodiment of the present application; Figure 2 is a schematic diagram of a base and an upper pressure plate in an embodiment of the present application; Figure 3 Schematic diagram of thickness measurement steps of a flexible aerogel product in one embodiment of the present application.

[0020] In the figure, 100, base; 101, ball seat; 102, lower pressure plate; 200, upper pressure plate; 201, pin hole; 300, hardness tester for flexible aerogel; 301, outer cylinder; 302, inner cylinder; 303, pressure rod; 3031, plane disk; 3032, pressure head; 3033, first limit step; 3034, second limit step; 304, first spring; 305, second spring; 306, strain gauge; 307, display calculation unit; 308, wire; 309, counterweight stabilization plate; 400, laser rangefinder. DETAILED DESCRIPTION

[0021] The specific implementation of the present application is described in detail below with reference to the accompanying drawings.

[0022] Embodiment 1: A method for testing the compressive strength of a flexible aerogel product, comprising the following steps: S1: Prepare 2 square specimens; S2: applying a first pressure to the first sample, measuring the maximum deformation of the first sample and converting it into the hardness of the sample; S3: According to the hardness of the sample obtained in step S2, the hardness-compression strength comparison table is searched to obtain the pressure required to flatten the sample, which is recorded as the second pressure; S4: pressing a second sample with a second pressure, and measuring the thickness of the flattened second sample to obtain a thickness D1 of the sample; S5: Calculate the sample compression strength value point thickness D2 according to the sample thickness D1, and calculate the compression test cut-off displacement D3 according to the sample compression strength value point thickness D2; S6: Press the thickness of the second sample to D3 at a set rate; If the sample still has no yield point after being compressed to D3, the compressive strength of the sample is calculated based on the force value when the sample is compressed to D2; If the sample shows a yield point when compressed to D3, the compressive strength of the sample is calculated using the yield point force value.

[0023] The hardness-compression strength comparison table is obtained by the following method: Hardness and compression strength tests were performed on several existing flexible aerogel products to obtain the corresponding relationship between the hardness and compression strength of the samples. Flattening tests were performed on several existing flexible aerogel products to obtain the compression strength of the samples when flattened. A scatter plot of sample hardness-compression strength was drawn and fitted with a curve. A scatter plot of sample hardness-compression strength when flattened was drawn and fitted with a curve.

[0024] The steps S2 and S4 are implemented by a thickness testing device for flexible aerogel products, such as Figure 1-2 As shown, the thickness testing device for flexible aerogel products comprises a base, an upper pressing plate and a hardness tester for flexible aerogel; The flexible aerogel hardness tester comprises: An outer cylinder, wherein a counterweight stabilizing plate is disposed on the outer side of the bottom of the outer cylinder, and the counterweight stabilizing plate is mounted on the base; An inner cylinder, wherein the contents are arranged in the outer cylinder, and the top of the inner cylinder is fixedly connected to the top of the outer cylinder; A pressure rod, wherein a flat plate is provided at the top of the pressure rod, and the flat plate is used to be connected to the bottom of the upper pressure plate, the pressure rod passes through the inner cylinder and a pressure head is provided at the bottom of the pressure rod; A first spring, wherein the first spring is arranged between the pressure rod and the inner cylinder, and two ends of the first spring are respectively fixedly connected to the top of the inner cylinder and the pressure head; Two strain gauges, which are respectively arranged on the upper side of the inner cylinder and at the junction of the pressure head and the spring; and a display calculation unit connected to the two strain gauges for calculating and displaying the displacement detected by the strain gauges.

[0025] When executing step S2, the hardness tester for the flexible aerogel is placed between the base and the upper pressing plate, and when executing step S4, the hardness tester for the flexible aerogel is taken out from between the base and the upper pressing plate.

[0026] The working surface of the pressure head is a spherical surface, and the pressure head is provided with a first limiting step with a diameter larger than the diameter of the inner cylinder. The first spring provides a pulling force to the pressure head, and the first limiting step is used to limit the pressure head to prevent the pressure head from retracting into the inner cylinder. At the same time, after the test, the first spring can drive the pressure head to reset.

[0027] The pressure rod is provided with a second limiting step at a position above the outer cylinder, and a second spring is provided between the outer cylinder and the second limiting step. The second limiting step limits the downward pressure of the pressure rod, preventing the flat disk at the top of the pressure rod from contacting the outer cylinder and causing damage to the device. The second spring protects the device, and when the pressure rod is pressed down, the second limiting step compresses the second spring, preventing the second limiting step from directly contacting the outer cylinder and causing damage to the device.

[0028] The display and calculation unit is arranged on the surface of the outer cylinder, the strain gauge is connected to the display and calculation unit through a wire, and grooves are arranged on the inner cylinder and the outer cylinder for wiring of the wire.

[0029] The base comprises a ball seat and a lower pressing plate. The ball seat is provided with a spherical groove, and the bottom of the lower pressing plate is provided with a convex block matched with the spherical groove.

[0030] The lower pressing plate is provided with at least three non-collinear laser rangefinders, the laser rangefinders are embedded in the lower pressing plate and the upper surface of the laser rangefinders is not higher than the upper surface of the lower pressing plate, and the bottom of the upper pressing plate is provided with a reflective film corresponding to the laser rangefinders one by one. In this embodiment, the upper pressing plate and the lower pressing plate are both rectangular, and the laser rangefinders have four laser rangefinders respectively arranged at the four corners of the lower pressing plate. Similarly, reflective films are respectively attached to the four corners of the upper pressing plate.

[0031] The ball seat is used to adjust the direction of the lower pressure plate. Through the readings of the 4 laser rangefinders, the lower pressure plate can be adjusted to be parallel to the upper pressure plate. Before testing, the lower pressure plate should be adjusted to be parallel to the upper pressure plate.

[0032] The hardness tester for flexible aerogel also includes an electronic universal testing machine. The pressure of the pressure rod in the hardness tester for flexible aerogel is provided by the electronic universal testing machine. The upper pressure plate is provided with a connecting rod with a pin hole for connecting with the crossbeam of the electronic universal testing machine.

[0033] In step S2, the deformation of the first sample is obtained by the strain gauge. The sample hardness HP is obtained by the following formula:

[0034] Wherein, HP is the hardness of the customized flexible aerogel product of this embodiment; A is the area of ​​the upper platen; S is the bearing pressure of the upper pressure plate; k is the first spring elastic coefficient; G is the weight of the hardness tester system for flexible aerogel, which is a constant value; d is the spherical radius of the indenter; x is the strain gauge displacement.

[0035] In step S4, the thickness of the second sample is measured and obtained by reading the laser rangefinder.

[0036] When testing the thickness of flexible aerogel products, cut a sample of a certain size. Adjust the upper and lower pressure plates to be parallel by adjusting the ball seat, place the prepared sample with the concave surface facing down in the center of the lower pressure plate, then place the flexible aerogel hardness tester in the center of the sample, and apply a fixed pressure to the flat plate on the top of the flexible aerogel hardness tester with an electronic universal testing machine. Read the maximum value of the display screen of the outer cylinder as the hardness of the flexible aerogel. According to the comparison table of hardness and pressure, determine the pressure required to press the sample of the test hardness to flatness. After removing this sample and the flexible aerogel hardness tester, place a new sample of the same size in the center of the lower pressure plate, and use the pressure obtained by comparison to press the aerogel product. After the reading of the laser rangefinder stabilizes, take the distance reading, which is the true thickness of the aerogel product.

[0037] The method is further described below using a typical flexible aerogel product.

[0038] Test sample status: bulk density is 200kg / m3, nominal thickness is 10mm, the actual thickness of the flattened sample is 12.32mm, the sample is 20mm long, 20mm wide, the thickness is the original thickness of the product, the length direction is a straight edge, the width direction is an arc edge with a curvature radius of 300mm, and the overall shape is close to a tile.

[0039] The compression strength test was conducted using the GB / T 34336 test method: After testing the sample size according to ISO 29768, a steel plate with a pressure of 350Pa was used to flatten the sample. After calculation, the mass of the steel plate was 1.4kg, and the sample arc was not flattened. When the concave surface was facing downward, the maximum distance between the sample and the lower bottom plate was about 15mm. The sample was compressed using the GB 13480 test method at a constant rate of 0.1d / min. Since the sample had no yield point, the compression strength value was calculated by taking the force value from the zero point of displacement to 25% of the thickness using the displacement reading of the strength machine. The sample did not contact the pressure plate at the initial position, resulting in the compression strength value of the test only representing the deformation strength of the sample curvature under pressure, rather than the compression strength of the sample. The test value was 52 kPa, which did not meet the standard qualification line.

[0040] The method of this embodiment is used to perform the compression strength test: the test steps are as follows: Figure 3 As shown, after cutting the sample, place the sample with the concave surface facing upward on the horizontally adjusted ball seat chassis, place a flexible aerogel hardness tester in the center of the sample, adjust the strength machine crossbeam so that the upper pressure plate of the strength machine exerts a force of 5kPa on the flat plate where the flexible aerogel hardness tester applies pressure, and the spherical pressure head of the hardness tester presses into the upper surface of the sample without producing a piercing effect. The pressure head displacement of the flexible aerogel hardness tester at this time is displayed on the display screen through the capacitive strain gauge, and the maximum value represents the hardness of the sample. By querying the hardness-prepressure comparison table, it can be found that the pressure required to flatten the sample is 850Pa. Place a new sample on the horizontally adjusted ball seat chassis of the strength machine, adjust the crossbeam so that the upper pressure plate of the strength machine exerts a force of 850Pa on the sample. At this time, the laser rangefinder records the reading as D1, D1 represents the initial thickness of the sample, and 25%D1 is calculated to obtain D2, D2 is the compression strength value point, or other agreed compression strength value thickness ratios are specified. Take 1.5 times the D2 data as D3, and D3 is the cut-off displacement of the compression test to ensure that the sample will not have a yield point during the loading process. The strength machine is used to compress the sample at an agreed rate, generally 0.1d / min, until the upper platen displacement reaches D3, and the force value corresponding to the D2 displacement is found on the strength machine display to calculate the compression strength. The compression strength value of the sample measured in this way is 92 kPa, which exceeds the standard qualified line and conforms to the actual situation.

[0041] Embodiment 2: A hardness tester for flexible aerogel, comprising: An outer cylinder, wherein a counterweight stabilizing plate is disposed on the outer side of the bottom of the outer cylinder, and the counterweight stabilizing plate is mounted on the base; An inner cylinder, wherein the contents are arranged in the outer cylinder, and the top of the inner cylinder is fixedly connected to the top of the outer cylinder; A pressure rod, wherein a flat plate is provided at the top of the pressure rod, and the flat plate is used to be connected to the bottom of the upper pressure plate, the pressure rod passes through the inner cylinder and a pressure head is provided at the bottom of the pressure rod; A first spring, wherein the first spring is arranged between the pressure rod and the inner cylinder, and two ends of the first spring are respectively fixedly connected to the top of the inner cylinder and the pressure head; Two strain gauges, which are respectively arranged on the upper side of the inner cylinder and at the junction of the pressure head and the spring; and a display calculation unit connected to the two strain gauges for calculating and displaying the displacement detected by the strain gauges.

[0042] The working surface of the pressure head is a spherical surface, and the pressure head is provided with a first limiting step with a diameter larger than the diameter of the inner cylinder. The first spring provides a pulling force to the pressure head, and the first limiting step is used to limit the pressure head to prevent the pressure head from retracting into the inner cylinder. At the same time, after the test, the first spring can drive the pressure head to reset.

[0043] The pressure rod is provided with a second limiting step at a position above the outer cylinder, and a second spring is provided between the outer cylinder and the second limiting step. The second limiting step limits the downward pressure of the pressure rod, preventing the flat disk at the top of the pressure rod from contacting the outer cylinder and causing damage to the device. The second spring protects the device, and when the pressure rod is pressed down, the second limiting step compresses the second spring, preventing the second limiting step from directly contacting the outer cylinder and causing damage to the device.

[0044] The display and calculation unit is arranged on the surface of the outer cylinder, the strain gauge is connected to the display and calculation unit through a wire, and grooves are arranged on the inner cylinder and the outer cylinder for wiring of the wire.

[0045] Embodiment 3: A thickness testing device for a flexible aerogel product, comprising a base, an upper pressure plate, an electronic universal testing machine, and a hardness tester for a flexible aerogel as described in Embodiment 2; The base comprises a ball seat and a lower pressing plate, the ball seat is provided with a spherical groove, and the bottom of the lower pressing plate is provided with a convex block matching with the spherical groove; The lower pressing plate is provided with at least three non-collinear laser rangefinders, the laser rangefinders are embedded in the lower pressing plate and the upper surface of the laser rangefinders is not higher than the upper surface of the lower pressing plate, and the bottom of the upper pressing plate is provided with a reflective film corresponding to the laser rangefinders one by one; The upper pressing plate is provided with a connecting rod with a pin hole, which is used for connecting with the crossbeam of the electronic universal testing machine.

[0046] The above is only a preferred implementation of the present application. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present application, and these all fall within the scope of protection of the present application.

Claims

1. A method for testing the compressive strength of a flexible aerogel product, characterized in that: The following steps are involved: S1: Prepare 2 square specimens; S2: applying a first pressure to the first sample, measuring the maximum deformation of the first sample and converting it into the hardness of the sample; S3: According to the hardness of the sample obtained in step S2, the hardness-compression strength comparison table is searched to obtain the pressure required to flatten the sample, which is recorded as the second pressure; S4: pressing a second sample with a second pressure, and measuring the thickness of the flattened second sample to obtain a thickness D1 of the sample; S5: Calculate the sample compression strength value point thickness D2 according to the sample thickness D1, and calculate the compression test cut-off displacement D3 according to the sample compression strength value point thickness D2; S6: Press the thickness of the second sample to D3 at a set rate; If the sample still has no yield point after being compressed to D3, the compressive strength of the sample is calculated based on the force value when the sample is compressed to D2; If the sample shows a yield point when compressed to D3, the compressive strength of the sample is calculated using the yield point force value.

2. The compressive strength testing method for flexible aerogel products according to claim 1, characterized in that: The hardness-compression strength comparison table is obtained by the following method: The hardness and compression strength of several existing flexible aerogel products were tested to obtain the corresponding relationship between the hardness and compression strength of the samples; A flattening test was performed on several existing flexible aerogel products to obtain the compressive strength of the samples when they were flattened; Draw a scatter plot of sample hardness-compression strength and use curve fitting; Plot the specimen hardness versus compressive strength when flattened and use a curve fit.

3. The compressive strength testing method for flexible aerogel products according to claim 1, characterized in that: The steps S2 and S4 are implemented by a thickness testing device for flexible aerogel products, wherein the thickness testing device for flexible aerogel products comprises a base, an upper pressing plate and a hardness tester for flexible aerogel; The flexible aerogel hardness tester comprises: An outer cylinder, wherein a counterweight stabilizing plate is disposed on the outer side of the bottom of the outer cylinder, and the counterweight stabilizing plate is mounted on the base; An inner cylinder, wherein the contents are arranged in the outer cylinder, and the top of the inner cylinder is fixedly connected to the top of the outer cylinder; A pressure rod, wherein a flat plate is provided at the top of the pressure rod, and the flat plate is used to be connected to the bottom of the upper pressure plate. The pressure rod passes through the inner cylinder and a pressure head is provided at the bottom of the pressure rod; A first spring, wherein the first spring is arranged between the pressure rod and the inner cylinder, and two ends of the first spring are respectively fixedly connected to the top of the inner cylinder and the pressure head; Two strain gauges, which are respectively arranged on the upper side of the inner cylinder and at the junction of the pressure head and the spring; and a display calculation unit connected to the two strain gauges and used for calculating and displaying the displacement detected by the strain gauges; When executing step S2, the hardness tester for the flexible aerogel is placed between the base and the upper pressing plate, and when executing step S4, the hardness tester for the flexible aerogel is taken out from between the base and the upper pressing plate.

4. The compressive strength testing method for flexible aerogel products according to claim 3, characterized in that: The working surface of the pressure head is a spherical surface. The pressure head is provided with a first limiting step whose diameter is larger than the diameter of the inner cylinder. When the first limiting step contacts the inner cylinder, the lower end surface of the pressure head is flush with the bottom surface of the counterweight stabilizing plate.

5. The compressive strength testing method for flexible aerogel products according to claim 3, characterized in that: The position of the pressure rod above the outer cylinder is provided with a second limiting step, and a second spring is provided between the outer cylinder and the second limiting step.

6. The compressive strength testing method for flexible aerogel products according to claim 3, characterized in that: The display and calculation unit is arranged on the surface of the outer cylinder, the strain gauge is connected to the display and calculation unit through a wire, and grooves are arranged on the inner cylinder and the outer cylinder for wiring of the wire.

7. The compressive strength testing method for flexible aerogel products according to claim 3, characterized in that: The base comprises a ball seat and a lower pressing plate. The ball seat is provided with a spherical groove, and the bottom of the lower pressing plate is provided with a convex block matched with the spherical groove.

8. The compressive strength testing method for flexible aerogel products according to claim 3, characterized in that: The lower pressing plate is provided with at least three non-collinear laser rangefinders, the laser rangefinders are embedded in the lower pressing plate and the upper surface of the laser rangefinders is not higher than the upper surface of the lower pressing plate, and the bottom of the upper pressing plate is provided with reflective films corresponding to the laser rangefinders one by one.

9. The compressive strength testing method for flexible aerogel products according to claim 3, characterized in that: The thickness testing device for flexible aerogel products also includes an electronic universal testing machine. The pressure of the pressure rod in the flexible aerogel hardness tester is provided by the electronic universal testing machine. The upper pressure plate is provided with a connecting rod with a pin hole for connecting with the crossbeam of the electronic universal testing machine.

10. The compressive strength testing method for flexible aerogel products according to claim 3, characterized in that: In step S2, the deformation of the first sample is obtained by a strain gauge; in step S4, the thickness of the second sample is measured and obtained by reading the laser rangefinder.

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