Airtightness test method before and after high-temperature aging and clamping test device

Abstract

The application discloses a kind of high-temperature aging before and after air tightness test method and clamping test device, wherein test method includes the following steps: S1, the arc concave surface of composite material structure piece is closely attached to the arc convex surface of mounting seat, and cover the first opening of pressure measuring cavity;S2, detachably connected with the pressing seat on mounting seat, the arc concave surface of pressing seat is closely attached to the arc convex surface of composite material structure piece;Pressing seat is provided with through slot in the position corresponding to first opening;S3, stop after inflating to the pressure in pressure measuring cavity reaches standard pressure, and obtain first permeability according to the pressure variation in pressure measuring cavity after stopping inflation;S4, together with pressing seat, composite material structure piece and mounting seat are moved into high temperature furnace and heated, so that composite material structure piece produces aging;S5, composite material structure piece is cooled to room temperature, and repeat step S3 and obtain second permeability.The application realizes accurate air tightness measurement to complex composite material structure piece.

Description

Technical Field

[0001] This invention relates to the field of aero-engine testing technology, specifically to a method and clamping test device for airtightness testing before and after high-temperature aging. Background Technology

[0002] A high thrust-to-weight ratio / power-to-weight ratio is a development trend in aero-engines, with structural weight reduction being a key approach. For large individual components in aero-engines, such as the compressor casing, replacing traditional metal materials with lightweight composite materials can yield significant weight reduction benefits. Resin-based composite materials, due to their advantages such as low density, high strength, strong structural design flexibility, good fatigue resistance, and excellent damping and vibration reduction performance, are considered ideal structural materials for cold-end components of aero-engines. With the further development of aero-engines, even cold-end components must withstand high temperatures. Under long-term service conditions, composite materials are prone to damp heat aging. Damp heat aging significantly affects the airtightness of composite materials, especially structures such as the air intake mounting base and vent valve mounting base of the aero-engine casing, which require guaranteed airtightness. Therefore, airtightness testing of composite structural components before and after high-temperature aging plays a crucial role.

[0003] Traditional methods for testing the airtightness of composite structural components involve measuring the permeation of pressurized gas through a composite sample using a specialized testing device. Specifically, the composite sample is tightly secured within a test module using a sealing element. The test module is then divided into an inflation chamber and a pressure measurement chamber along the front-to-back direction. Pressurized gas is then injected into the inflation chamber, creating a pressure difference between the front and back sides of the composite sample. Under this pressure difference, the pressurized gas permeates through the sample along the front-to-back direction, and the permeation rate is measured using a specialized flow meter. However, this method is only suitable for short-term permeation measurements and cannot reflect the changes or deterioration trends in the airtightness of composite samples under long-term operating conditions. Furthermore, it is not suitable for accurately measuring the airtightness of composite samples with concave and convex arc surfaces at both ends. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the existing air tightness test methods are not convenient for accurately measuring the air tightness of composite material samples with concave and convex arc surfaces at the front and rear ends respectively, thereby providing an air tightness test method and clamping test device before and after high temperature aging.

[0005] In a first aspect, the present invention provides a method for testing the airtightness of composite material structural components before and after high-temperature aging, applicable to conducting airtightness tests on composite material structural components, wherein the composite material structural components have concave and convex arc surfaces at both ends along the thickness direction of the composite material structural components, respectively; the test method includes the following steps:

[0006] S1, the concave surface of the composite material structure is tightly fitted to the convex surface of the mounting base, the concave surface matches the convex surface and covers the first opening of the pressure measuring chamber;

[0007] S2, a clamping seat is detachably connected to one end of the mounting base facing the composite material structure. The arc-shaped concave surface of the clamping seat matches the arc-shaped convex surface and fits tightly against the arc-shaped convex surface. A through groove is provided through the clamping seat along the thickness direction of the composite material structure at the position corresponding to the first opening.

[0008] S3, inflate the pressure measuring chamber until the pressure inside the chamber reaches the standard pressure and then stop, and obtain the first permeability based on the pressure change inside the pressure measuring chamber after the inflation stops;

[0009] S4, the mounting base, the composite material structural component and the clamping base are moved together into a high-temperature furnace and heated at a set temperature to cause the composite material structural component to age.

[0010] S5, cool the composite material structure to room temperature, and repeat step S3 to obtain the second permeability;

[0011] S6, based on the first permeability and the second permeability, obtain the degree of change in air tightness of the composite material structure before and after high-temperature aging.

[0012] The airtightness test method before and after high-temperature aging according to the present invention has at least the following technical effects:

[0013] 1. By providing arc-shaped convex and arc-shaped concave surfaces on the opposing end faces of the mounting base and clamping base, respectively, with the arc-shaped convex surface matching the arc-shaped concave surface and vice versa, after the composite material structural component is clamped between the mounting base and clamping base, the arc-shaped concave surface and the arc-shaped convex surface tightly abut against and fit against the arc-shaped convex surface and the arc-shaped concave surface, respectively, ensuring no leakage. This prevents leakage from the space between the arc-shaped concave surface and the arc-shaped convex surface and the arc-shaped convex surface and the arc-shaped concave surface after the pressure measuring chamber is stopped being filled. The leakage between the convex surfaces ensures that the gas in the pressure measuring chamber, under the action of pressure difference, only permeates the composite material structure along the thickness direction and diffuses to the outside through the channel. This ensures that the permeability performance (i.e., permeability) of the composite material structure can be accurately obtained by calculating the pressure change per unit time in the pressure measuring chamber after the gas filling stops. Furthermore, by comparing the magnitude of the first permeability and the second permeability, it is possible to determine whether the change in airtightness of the composite material structure before and after high-temperature aging meets the usage requirements of the cold end components of the aero-engine. The entire test process is simplified and the measurement accuracy is high.

[0014] 2. By using the combination of arc-shaped convex and arc-shaped concave surfaces, a sealed clamping and fixing of composite material structural components is achieved. During the clamping and sealing process, the composite material structural components are not squeezed to cause large deformation or even damage. This enables high-precision airtightness testing without damaging the composite material structural components. Furthermore, after the test, the clamping seat and the mounting seat can be disassembled and reused, allowing the composite material structural components to be removed and reused, which helps to reduce the cost of airtightness testing.

[0015] In one optional implementation, obtaining the first permeability based on the pressure change in the pressure measuring chamber after inflation is stopped includes:

[0016] After stopping inflation and after a first set time interval, the pressure inside the pressure measuring chamber is measured to obtain the first pressure, and the first permeability is calculated using the following formula:

[0017]

[0018] In the formula, A1 represents the first permeability, P1 represents the first pressure, P0 represents the standard pressure, T1 represents the first set time, and P0-P1 represents the pressure change in the pressure measuring chamber.

[0019] In one optional embodiment, the composite material structural component has a through hole provided along the thickness direction of the composite material structural component at the position corresponding to the first opening; before inflating the pressure measuring chamber, the end of the through hole facing away from the mounting base is sealed.

[0020] In an optional implementation, the following steps are further included between step S3 and step S4:

[0021] The gas in the pressure measuring chamber is released until the pressure inside the pressure measuring chamber reaches atmospheric pressure.

[0022] In one optional embodiment, cooling the composite material structural member to room temperature includes:

[0023] After shutting down the high-temperature furnace and allowing the composite material structural component to cool to room temperature, remove the mounting base, the composite material structural component, and the clamping base together from the high-temperature furnace.

[0024] Secondly, the present invention also provides a clamping test device for implementing the airtightness test method before and after high-temperature aging provided in the first aspect, the clamping test device comprising:

[0025] The mounting base has a pressure measuring chamber inside, and a first opening communicating with the pressure measuring chamber is provided through the first end of the mounting base; the first end of the mounting base is provided with an arc-shaped convex surface that matches the arc concave surface;

[0026] A clamping seat is detachably connected to the first end of the mounting base. The end of the clamping seat facing the mounting base is provided with an arc-shaped concave surface, which matches the arc-shaped convex surface. The clamping seat is provided with a through groove along the thickness direction of the composite material structure at the position corresponding to the first opening.

[0027] According to the clamping test device of the present invention, at least the following technical effects are achieved:

[0028] 1. By providing arc-shaped convex and concave surfaces on the opposing end faces of the mounting base and clamping base, respectively, with the arc-shaped convex surface matching the arc-shaped concave surface and vice versa, after the composite material structural component is clamped between the mounting base and clamping base, the arc-shaped concave and convex surfaces tightly abut and fit against the arc-shaped convex and concave surfaces, respectively, ensuring a leak-free sealing contact between the arc-shaped concave and convex surfaces and between the arc-shaped convex and concave surfaces; during the airtightness test using this clamping test device, it is ensured that... After the gas filling the pressure measuring chamber is stopped, the gas in the pressure measuring chamber will not leak from the arc-shaped convex surface and the arc-shaped concave surface, or from the arc-shaped concave surface and the arc-shaped convex surface. This ensures that the gas in the pressure measuring chamber, under the action of pressure difference, will only permeate the composite material structure along the thickness direction and diffuse to the outside through the through groove. This ensures that the permeability performance (i.e., permeability) of the composite material structure can be accurately obtained by calculating the pressure change per unit time in the pressure measuring chamber after the gas filling is stopped. The whole test process is more simplified and the measurement accuracy is high.

[0029] 2. By using the combination of arc-shaped convex and arc-shaped concave surfaces, a sealed clamping and fixing of composite material structural components is achieved. During the clamping and sealing process, the composite material structural components are not squeezed to cause large deformation or even damage. This enables high-precision airtightness testing without damaging the composite material structural components. Furthermore, after the test, the clamping seat and the mounting seat can be disassembled and reused, allowing the composite material structural components to be removed and reused, which helps to reduce the cost of airtightness testing.

[0030] In one alternative embodiment, the mounting base and the clamping base are detachably connected as one unit via a locking assembly.

[0031] In one alternative embodiment, the locking assembly includes a matching locking bolt and a locking nut; the mounting base and the clamping base are provided with a first through hole along the thickness direction of the composite material structure, the first through hole being for the shank of the locking bolt to pass through.

[0032] In one optional embodiment, the locking assembly includes a locking bolt, and the clamping seat has a second through hole extending along the thickness direction of the composite material structure, the second through hole being for the shank of the locking bolt to pass through; the mounting seat has a threaded hole at a position corresponding to the second through hole on its end face facing the clamping seat, the threaded hole being matched with the locking bolt.

[0033] In one optional embodiment, a first sealing gasket is provided on the end face of the arcuate convex surface facing the arcuate concave surface;

[0034] And / or, a second sealing gasket is provided on the end face of the arc-shaped concave surface facing the arc-shaped convex surface. Attached Figure Description

[0035] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0036] Figure 1 This is a front view schematic diagram of a clamping test device for sealing and clamping composite material structural components according to this embodiment;

[0037] Figure 2 for Figure 1 A schematic diagram of the decomposed structure;

[0038] Figure 3 for Figure 1 A top-view structural diagram.

[0039] Explanation of reference numerals in the attached figures:

[0040] 100 - Composite material structural component, 110 - Concave arc surface, 120 - Convex arc surface, 130 - Perforation, 140 - Frustum;

[0041] 200-Mounting base, 210-Mounting plate, 211-Arc-shaped convex surface, 212-First opening, 220-Connecting part, 230-Ventilation hole;

[0042] 300-Clamping seat, 310-Arc-shaped concave surface, 320-Through groove, 330-First through hole;

[0043] 410 - Locking bolt, 420 - Locking nut. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of this embodiment, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "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 embodiment 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 embodiment. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] In the description of this embodiment, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment according to the specific circumstances.

[0047] The following is combined with Figures 1 to 3 The following describes embodiments of the present invention.

[0048] According to a first aspect of the present invention, a method for airtightness testing before and after high-temperature aging is provided, applied to airtightness testing of a composite material structural component 100, wherein the composite material structural component 100 has a concave arc surface 110 and a convex arc surface 120 respectively provided at both ends along the thickness direction of the composite material structural component 100; the testing method includes the following steps:

[0049] S1, the concave surface 110 of the composite material structural component 100 is tightly fitted to the convex surface 211 of the mounting base 200. The concave surface 110 matches the convex surface 211 and covers the first opening 212 of the pressure measuring cavity located in the mounting base 200.

[0050] S2, a clamping seat 300 is detachably connected to one end of the mounting base 200 facing the composite material structure 100. The arc-shaped concave surface 310 of the clamping seat 300 matches the arc-shaped convex surface 120 and fits tightly against the arc-shaped convex surface 120. The clamping seat 300 is provided with a through groove 320 along the thickness direction of the composite material structure 100 at the position corresponding to the first opening 212.

[0051] S3, inflate the pressure measuring chamber until the pressure inside the chamber reaches the standard pressure and then stop, and obtain the first permeability based on the pressure change inside the pressure measuring chamber after the inflation stops;

[0052] S4, the mounting base 200, the composite material structural component 100 and the clamping base 300 are moved into the high temperature furnace together, heated to the set temperature and then the heating is stopped and kept warm. The set temperature is preferably 350°C, so that the composite material structural component 100 will age.

[0053] S5, cool the composite material structure 100 to room temperature, and repeat step S3 to obtain the second permeability;

[0054] S6. The first permeability and the second permeability are compared to obtain the first difference. The first difference is then compared with the standard deviation. If the first difference is greater than the standard deviation, the air tightness of the composite material structural component 100 after high-temperature aging cannot meet the requirements of the cold end component of the aero-engine. If the first difference is less than or equal to the standard deviation, the air tightness of the composite material structural component 100 after high-temperature aging meets the requirements of the cold end component of the aero-engine.

[0055] The airtightness test method before and after high-temperature aging in this embodiment uses arc-shaped convex surfaces 211 and arc-shaped concave surfaces 310 respectively provided on the mutually facing end faces of the mounting base 200 and the clamping base 300. The arc-shaped convex surface 211 matches the arc-shaped concave surface 110, and the arc-shaped concave surface 310 matches the arc-shaped convex surface 120. After the composite material structural component 100 is clamped between the mounting base 200 and the clamping base 300, because the arc-shaped concave surface 110 and the arc-shaped convex surface 120 are tightly abutted and attached to the arc-shaped convex surface 211 and the arc-shaped concave surface 310 respectively, the arc-shaped concave surface 110 and the arc-shaped convex surface 211 and the arc-shaped convex surface 120 and the arc-shaped concave surface 310 are sealed and do not leak. This ensures that after the gas filling into the pressure measuring chamber stops, the gas in the pressure measuring chamber is basically leak-free. This prevents leakage between the convex arc surface 120 and the concave arc surface 310, and between the concave arc surface 110 and the convex arc surface 211. This ensures that the gas in the pressure measuring chamber, under the action of pressure difference, only permeates the composite material structure 100 along the thickness direction and diffuses to the outside through the through groove 320. This ensures that the permeability performance (i.e., permeability) of the composite material structure 100 can be accurately obtained by calculating the pressure change per unit time in the pressure measuring chamber after the gas filling stops. Furthermore, by comparing the magnitude of the first permeability and the second permeability, it is possible to determine whether the change in air tightness of the composite material structure 100 before and after high-temperature aging meets the usage requirements of the cold end components of the aero-engine. The entire test process is simplified and the measurement accuracy is high. During the test, the composite material structure 100 is sealed and clamped by the cooperation of the arc-shaped convex surface 211 and the arc-shaped concave surface 310. During the clamping and sealing process, the composite material structure 100 will not be squeezed and will not be subjected to large deformation or even damage. This allows for high-precision airtightness testing without damaging the composite material structure 100. After the test, the clamping seat 300 and the mounting seat 200 can be disassembled and reused. This allows the clamping seat 300 and the mounting seat 200 to be reused after the composite material structure 100 is removed, which helps to reduce the cost of airtightness testing.

[0056] It should be noted that, because during the airtightness test of the composite material structural component 100 before and after high-temperature aging using the airtightness test method of this embodiment, after the gas filling the pressure measuring chamber is stopped, the gas in the pressure measuring chamber, under the action of pressure difference, basically only permeates the composite material structural component 100 along the thickness direction and diffuses to the outside through the through groove 320; therefore, during the test, it is not necessary to connect the sealing cavity to the end of the through groove 320 that is relatively opposite to the composite material structural component 100, nor is it necessary to measure the pressure change of the sealing cavity and compare and analyze the pressure change of the pressure measuring cavity and the pressure change of the sealing cavity to obtain a correction value to compensate for the amount of gas leaking from the arc convex surface 120 and the arc concave surface 310 and the arc concave surface 110 and the arc convex surface 211 after the gas filling in the pressure measuring chamber is stopped; it is only necessary to calculate the pressure change per unit time in the pressure measuring chamber after the gas filling is stopped to accurately obtain the permeability performance (i.e., permeability) of the composite material structural component 100, making the entire test process simpler and the measurement accuracy higher.

[0057] It should be noted that, during the airtightness test of the composite material structural component 100 before and after high-temperature aging using the airtightness test method of this embodiment, after the gas filling the pressure measuring chamber is stopped, the gas in the pressure measuring chamber basically only permeates the composite material structural component 100 along the thickness direction of the composite material structural component 100 under the action of pressure difference and diffuses to the outside through the through groove 320; therefore, the airtightness test method of this embodiment can obtain the change law of airtightness of the composite material structural component 100 under long-term working conditions by obtaining the pressure change of the pressure measuring chamber over a long period of time.

[0058] It should be noted that the standard pressure mentioned in the article refers to the pressure that the composite material structural component 100 withstands during normal operation after being assembled into the aircraft engine.

[0059] It is understandable that both the mounting base 200 and the clamping base 300 are made of airtight materials and will not produce any air permeability after being moved into a high-temperature furnace for heating and heat preservation.

[0060] It should be noted that the standard deviation mentioned in the article refers to the difference between the gas permeability of a qualified aero-engine cold-end component before high-temperature aging and the gas permeability of a qualified aero-engine cold-end component after high-temperature aging.

[0061] It should be noted that the set temperature mentioned in the article refers to the temperature that the composite material structural component 100 withstands during normal operation after being assembled into the aircraft engine; in specific applications, the set temperature can be reasonably selected according to actual conditions, for example, the set temperature can be set to 353℃, 355℃, 360℃, 365℃, etc.

[0062] Understandably, after obtaining the first permeability, it can be compared with the standard permeability. If the first permeability is greater than the standard permeability (meaning the permeability of the composite material structural component 100 before high-temperature aging does not meet the requirements for use in an aero-engine), then subsequent steps S4, S5, and S6 are unnecessary. If the first permeability is less than the standard permeability, then subsequent steps S4, S5, and S6 are performed normally. Specifically, the standard permeability refers to the gas permeability of a qualified aero-engine cold-end component before high-temperature aging.

[0063] Specifically, in this embodiment, the composite material structural component 100 refers to the air intake mounting seat 200 or the vent valve mounting seat 200 of the aero-engine casing. Both the air intake mounting seat 200 and the vent valve mounting seat 200 are cold end components of the aero-engine.

[0064] In some embodiments, obtaining the first permeability based on the pressure change in the pressure measuring chamber after inflation is stopped includes:

[0065] After stopping inflation and after a first set time interval, the pressure inside the pressure measuring chamber is measured using a pressure gauge to obtain the first pressure, and the first permeability is calculated using the following formula:

[0066]

[0067] In the formula, A1 represents the first permeability, P1 represents the first pressure, P0 represents the standard pressure, T1 represents the first set time, and P0-P1 represents the pressure change in the pressure measuring chamber.

[0068] In this embodiment, the first pressure is obtained by stopping the inflation of the pressure measuring chamber and allowing it to stand still for a first set time. The pressure inside the pressure measuring chamber is then measured using a pressure gauge, and the pressure change per unit time is calculated to accurately obtain the first permeability of the composite material structural component 100. After moving the mounting base 200, the composite material structural component 100, and the clamping base 300 together into a high-temperature furnace for heating and heat preservation to cause aging of the composite material structural component 100 and allowing it to cool down to the same temperature as when the first permeability of the composite material structural component 100 was measured (i.e., room temperature), the second permeability of the composite material structural component 100 can be accurately obtained using the same steps. The entire test process is more simplified and the measurement accuracy is higher.

[0069] In practical applications, the specific value of the first set duration can be reasonably increased or decreased according to the actual test requirements. For example, it can be set to a longer duration (e.g., 24 hours) to accurately obtain the change law of airtightness of composite material structural component 100 under long-term working conditions. It can also be set to a shorter duration (e.g., one hour) to accurately obtain the change law of airtightness of composite material structural component 100 under short-term working conditions.

[0070] Specifically, the composite material structural component 100 has a through-hole 130 corresponding to the first opening 212, extending along the thickness direction of the composite material structural component 100. Before inflating the pressure measuring chamber, the end of the through-hole 130 facing away from the mounting base 200 is sealed. In obtaining the first and second permeability rates, sealing the through-hole 130 ensures that after inflating the pressure measuring chamber stops, the gas in the pressure measuring chamber, under the influence of the pressure difference, primarily permeates the composite material structural component 100 along its thickness direction and diffuses to the outside through the through-slot 320.

[0071] It should be noted that when the composite material structural component 100 is assembled into the aero engine as a casing air intake mounting base 200 or vent valve mounting base 200, the perforation 130 is used to allow gas to pass through.

[0072] like Figure 1 and Figure 2 As shown, more specifically, the composite material structural component 100 has a truncated cone 140 protruding from one end opposite to the mounting base 200, a through hole 130 is provided through the truncated cone 140, and a through groove 320 provides space for the truncated cone 140 to pass through.

[0073] To further improve the high-temperature aging of the composite material structural component 100, specifically, the following steps are included between step S3 and step S4:

[0074] The gas in the pressure measuring chamber is released until the pressure inside the pressure measuring chamber reaches atmospheric pressure.

[0075] In some embodiments, cooling the composite material structural member 100 to room temperature includes:

[0076] After shutting down the high-temperature furnace and allowing the composite material structural component 100 to stand until its temperature drops to room temperature, remove the mounting base 200, the composite material structural component 100, and the clamping base 300 together from the high-temperature furnace.

[0077] This embodiment cools down the composite material structural component 100 by placing it in a relatively sealed and closed high-temperature furnace, which is closer to the trend of static cooling of the composite material structural component 100 after it is assembled into an aero-engine for normal use, thereby further improving the measurement accuracy of the airtightness of the composite material structural component 100 after high-temperature aging.

[0078] like Figures 1 to 3As shown, according to a second aspect of the present invention, a clamping test device is also provided for implementing the high-temperature aging airtightness test method provided in the first aspect of the present invention; the clamping test device includes a separately configured mounting base 200 and a clamping base 300, wherein a pressure measuring chamber is provided in the mounting base 200, and a first opening 212 communicating with the pressure measuring chamber is provided through the first end of the mounting base 200; an arc-shaped convex surface 211 matching the arc concave surface 110 is provided at the first end of the mounting base 200; the clamping base 300 is detachably connected to the first end of the mounting base 200 by a locking assembly, and an arc-shaped concave surface 310 is provided at the end of the clamping base 300 facing the mounting base 200, the arc concave surface 310 matching the arc convex surface 120; a through groove 320 is provided through the clamping base 300 along the thickness direction of the composite material structural component 100 at the position corresponding to the first opening 212.

[0079] The clamping test device of this embodiment has an arc-shaped convex surface 211 and an arc-shaped concave surface 310 respectively provided on the end faces of the mounting base 200 and the clamping base 300 facing each other. The arc-shaped convex surface 211 matches the arc-shaped concave surface 110, and the arc-shaped concave surface 310 matches the arc-shaped convex surface 120. After the composite material structural component 100 is clamped between the mounting base 200 and the clamping base 300, because the arc-shaped concave surface 110 and the arc-shaped convex surface 120 are tightly abutted and fitted against the arc-shaped convex surface 211 and the arc-shaped concave surface 310 respectively, the arc-shaped concave surface 110 and the arc-shaped convex surface 211 and the arc-shaped convex surface 120 and the arc-shaped concave surface 310 are sealed and do not leak. During the airtightness test of the clamping test device in the example, it is ensured that after the gas filling into the pressure measuring chamber is stopped, the gas in the pressure measuring chamber will not leak from the arc convex surface 120 and the arc concave surface 310 or from the arc concave surface 110 and the arc convex surface 211. This ensures that the gas in the pressure measuring chamber, under the action of pressure difference, will only permeate the composite material structural component 100 along the thickness direction and diffuse to the outside through the through groove 320. This ensures that the permeability performance (i.e., permeability) of the composite material structural component 100 can be accurately obtained by calculating the pressure change per unit time in the pressure measuring chamber after the gas filling is stopped. The whole test process is more simplified and the measurement accuracy is high. Simultaneously, the arc-shaped convex surface 211 and the arc-shaped concave surface 310 cooperate to achieve a sealed clamping and fixing of the composite material structural component 100. During the clamping and sealing process, the composite material structural component 100 will not be squeezed to cause large deformation or even damage. This allows for high-precision airtightness testing without damaging the composite material structural component 100. Furthermore, after the test, the clamping seat 300 and the mounting seat 200 can be disassembled and reused, which not only allows the composite material structural component 100 to be disassembled and reused, but also helps to reduce the cost of airtightness testing.

[0080] It is understandable that the first end of the mounting base 200 mentioned in the text refers to the end of the mounting base 200 facing the clamping base 300.

[0081] like Figure 1 and Figure 2 As shown, specifically, the side wall of the mounting base 200 is provided with a vent hole 230, which is connected to the pressure measuring chamber; it can both fill the pressure measuring chamber with air through the vent hole 230 during the measurement of the first permeability or the second permeability, and discharge the excess gas in the pressure measuring chamber through the vent hole 230 after the measurement of the first permeability or the second permeability is completed.

[0082] like Figure 1 and Figure 2 As shown, specifically, the mounting base 200 includes an integrally formed mounting plate 210 and a connecting portion 220. The cross-sectional area of ​​the connecting portion 220 perpendicular to the thickness direction of the composite material structural component 100 is smaller than the cross-sectional area of ​​the mounting plate 210 perpendicular to the thickness direction of the composite material structural component 100. An arc-shaped convex surface 211 is provided at one end of the mounting base 200 away from the connecting portion 220. A pressure measuring chamber is provided inside the connecting portion 220. The mounting plate 210, corresponding to the position of the pressure measuring chamber, penetrates along the thickness direction of the composite material structural component 100 to form a first opening 212. This makes the structure of the clamping test device in this embodiment more miniaturized, thereby facilitating the clamping test device in this embodiment to clamp and seal the composite material structural component 100 and transfer it to a high-temperature furnace for heating and heat preservation to achieve aging.

[0083] More specifically, the vent 230 is provided on the side wall of the connecting part 220.

[0084] The specific structure of the locking component in this embodiment will be described in detail below.

[0085] like Figure 1 and Figure 2As shown, in some embodiments, the locking assembly includes a matching locking bolt 410 and a locking nut 420; the mounting base 200 and the clamping base 300 are provided with a first through hole 330 through the thickness direction of the composite material structure 100, the first through hole 330 being used for the shank of the locking bolt 410 to pass through. During the process of clamping and sealing the composite material structural component 100 between the mounting base 200 and the clamping base 300, the concave surface 110 of the composite material structural component 100 is first abutted against the convex surface 211 of the mounting base 200, and the concave surface 310 of the clamping base 300 is abutted against the convex surface 120 of the composite material structural component 100. At this time, the first through holes 330 on the mounting base 200 and the clamping base 300 are aligned. Then, the shank of the locking bolt 410 passes through the first through hole 330 from top to bottom and extends outside the mounting base 200. The locking nut 420 is then threaded and tightened onto the part of the locking bolt 410 that extends outside the mounting base 200, thereby achieving a sealed clamping of the composite material structural component 100. After the test is completed, the mounting base 200, the composite material structural component 100, and the clamping base 300 can be separated simply by unscrewing the locking bolt 410.

[0086] Specifically, the clamping seat 300 is provided with a first through hole 330 at each of the four corners of the rectangular cross section perpendicular to the composite material structure 100.

[0087] As an alternative implementation of the above solution, the locking assembly includes a locking bolt 410, and a second through hole is provided on the clamping seat 300 along the thickness direction of the composite material structural member 100, the second through hole being used for the shank of the locking bolt 410 to pass through; the mounting seat 200 is provided with a threaded hole at a position corresponding to the second through hole on the end face facing the clamping seat 300, the threaded hole matching the locking bolt 410. During the process of clamping and sealing the composite material structural component 100 between the mounting base 200 and the clamping base 300, the concave arc surface 110 of the composite material structural component 100 is first abutted against the convex arc surface 211 of the mounting base 200, and the concave arc surface 310 of the clamping base 300 is abutted against the convex arc surface 120 of the composite material structural component 100. At this time, the second through hole and the threaded hole are aligned. Then, the shank of the locking bolt 410 is passed through the second through hole and screwed into the threaded hole, thus achieving the sealing and clamping of the composite material structural component 100. After the test is completed, the mounting base 200, the composite material structural component 100, and the clamping base 300 can be separated by simply unscrewing the locking bolt 410 from the threaded hole.

[0088] Specifically, a second through hole is provided at each of the four corners of the rectangular cross-section of the clamping seat 300 perpendicular to the composite material structural component 100.

[0089] In order to improve the sealing and clamping effect of the clamping test device on the composite material structure 100 in this embodiment, specifically, a first sealing gasket is provided on the end face of the arc-shaped convex surface 211 facing the arc-shaped concave surface 310.

[0090] In order to improve the sealing and clamping effect of the clamping test device on the composite material structural component 100 in this embodiment, specifically, a second sealing gasket is provided on the end face of the arc-shaped concave surface 310 facing the arc-shaped convex surface 211.

[0091] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for airtightness testing before and after high-temperature aging, applied to airtightness testing of a composite material structural component (100), wherein the composite material structural component (100) is an air vent mounting base or vent valve mounting base for an aero-engine casing, and wherein the composite material structural component (100) has a concave arc surface (110) and a convex arc surface (120) respectively provided at both ends along the thickness direction of the composite material structural component (100); characterized in that, The experimental method includes the following steps: S1, the concave surface (110) of the composite material structural component (100) is tightly fitted to the convex surface (211) of the mounting base (200), the concave surface (110) matches the convex surface (211) and covers the first opening (212) of the pressure measuring chamber. S2, a clamping seat (300) is detachably connected to one end of the mounting base (200) facing the composite material structure (100). The arc-shaped concave surface (310) of the clamping seat (300) matches the arc-shaped convex surface (120) and fits tightly against the arc-shaped convex surface (120). A through groove (320) is provided in the clamping seat (300) corresponding to the position of the first opening (212) along the thickness direction of the composite material structure (100). S3, inflate the pressure measuring chamber until the pressure inside the chamber reaches the standard pressure and then stop, and obtain the first permeability based on the pressure change inside the pressure measuring chamber after the inflation stops; S4, the mounting base (200), the composite material structural component (100) and the clamping base (300) are moved into a high-temperature furnace together and heated at a set temperature to cause the composite material structural component (100) to age; S5, the composite material structural component (100) is cooled to room temperature, and step S3 is repeated to obtain the second permeability; S6, based on the first permeability and the second permeability, obtain the degree of change in air tightness of the composite material structural component (100) before and after high-temperature aging; Cooling the composite material structural component (100) to room temperature includes: After shutting down the high-temperature furnace and allowing the composite material structural component (100) to stand until the temperature drops to room temperature, remove the mounting base (200), the composite material structural component (100), and the clamping base (300) together from the high-temperature furnace.

2. The method for testing airtightness before and after high-temperature aging according to claim 1, characterized in that, The step of obtaining the first permeability based on the pressure change in the pressure measuring chamber after inflation is stopped includes: After stopping inflation and after a first set time interval, the pressure inside the pressure measuring chamber is measured to obtain the first pressure, and the first permeability is calculated using the following formula: In the formula, This indicates the first penetration rate. Indicates the first pressure. Indicates standard pressure, Indicates the first set duration. This indicates the pressure change within the pressure measuring chamber.

3. The method for testing airtightness before and after high-temperature aging according to claim 1 or 2, characterized in that, The composite material structural component (100) has a through hole (130) provided along the thickness direction of the composite material structural component (100) at the position corresponding to the first opening (212); before filling the pressure measuring chamber with air, the end of the through hole (130) away from the mounting base (200) is sealed.

4. The airtightness test method before and after high-temperature aging according to claim 1, characterized in that, The following steps are also included between step S3 and step S4: The gas in the pressure measuring chamber is released until the pressure inside the pressure measuring chamber reaches atmospheric pressure.

5. A clamping test apparatus for implementing the airtightness test method before and after high-temperature aging as described in any one of claims 1 to 4, characterized in that, The clamping test device includes: The mounting base (200) has a pressure measuring chamber inside. The first end of the mounting base (200) has a first opening (212) that communicates with the pressure measuring chamber. The first end of the mounting base (200) has an arc-shaped convex surface (211) that matches the arc concave surface (110). A clamping seat (300) is detachably connected to the first end of the mounting seat (200). The end of the clamping seat (300) facing the mounting seat (200) is provided with an arc-shaped concave surface (310), which matches the arc-shaped concave surface (120). The clamping seat (300) is provided with a through groove (320) along the thickness direction of the composite material structure (100) at the position corresponding to the first opening (212).

6. The clamping test device according to claim 5, characterized in that, The mounting base (200) and the clamping base (300) are detachably connected as one unit by a locking assembly.

7. The clamping test device according to claim 6, characterized in that, The locking assembly includes a matching locking bolt (410) and a locking nut (420); the mounting base (200) and the clamping base (300) are provided with a first through hole (330) through the thickness direction of the composite material structure (100), the first through hole (330) being used for the shank of the locking bolt (410) to pass through.

8. The clamping test device according to claim 6, characterized in that, The locking assembly includes a locking bolt (410), and a second through hole is provided on the clamping seat (300) along the thickness direction of the composite material structure (100), the second through hole being for the shank of the locking bolt (410) to pass through; the mounting seat (200) has a threaded hole on the end face facing the clamping seat (300) corresponding to the second through hole, the threaded hole matching the locking bolt (410).

9. A clamping test device according to claim 6, characterized in that, The end face of the arc-shaped convex surface (211) facing the arc-shaped concave surface (310) is provided with a first sealing gasket; And / or, the end face of the arc-shaped concave surface (310) facing the arc-shaped convex surface (211) is provided with a second sealing gasket.

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