In-situ testing method for bonding strength of interface I of solid rocket engine

Abstract

The invention relates to a solid rocket engine I interface bonding strength in-situ test method, which comprises the following steps of: after horizontally positioning a shell, implementing nondestructive testing on the bottom of the inner wall of a straight cylinder section, positioning a test area meeting a preset condition, and synchronously obtaining thickness data of a heat insulation layer; adhering a hoisting clamp to the center of the test area, and performing full-circumferential annular cutting along the outer contour of the adhering area, so that the stress of the heat insulating layer of the adhering area and the stress of the heat insulating layer of the non-adhering area are isolated; a vertical loading system comprising a fixed pulley block, a flexible rope and a weight pan is constructed, and the flexible rope is connected with the hoisting clamp and is perpendicular to the bonding area after being tensioned; the standard weights are loaded in a graded mode till the first interface of the bonding area is stripped, and critical quality parameters are recorded in real time; and the bonding strength of the interface I is calculated according to the critical quality parameters and the bonding area. The method is simple in operation process and low in cost, can identify the weak adhesion defect that the interface is not layered, and can measure the adhesion strength of the first interface.

Description

Technical Field

[0001] The present invention relates to the technical field of solid rocket engines, and particularly to a method for in-situ testing the bonding strength of the first interface of a solid rocket engine. Background Art

[0002] Due to many advantages such as simple structure, excellent storage performance, and good mobility, solid rocket engines are widely used in various weapon missile systems. A solid rocket engine generally consists of key components such as a propellant combustion chamber, an ignition device, and a nozzle. Specifically, the propellant combustion chamber includes a casing, an insulation layer, a liner, and a propellant grain. Given that the materials of each component are different, during the production of solid rocket engines, the bonding of multiple material interfaces and their quality inspection are involved.

[0003] The first interface of a solid rocket engine refers to the bonding interface between the composite layer and the insulation layer on the casing. At present, the commonly used means for detecting the bonding quality of the first interface in the industry mainly include DR detection and CT detection.

[0004] DR detection, namely X-ray diffraction detection, is a non-destructive detection technology widely used in the detection and analysis of internal defects of materials. By emitting X-rays to the interface to be measured and receiving the X-rays reflected or transmitted by the interface, the microscopic structure and defect information inside the interface can be obtained. These information are crucial for evaluating the integrity and strength of the bonding interface. Specifically, DR detection can reveal whether there are defects such as cracks, pores, and inclusions in the bonding interface, as well as the size, shape, and distribution of these defects. Through the analysis of this information, the bonding quality and strength level of the bonding interface can be further inferred.

[0005] CT detection, namely computerized tomography technology, is an advanced non-destructive detection technology. It uses radiation sources such as X-rays or ultrasonic waves, and through precise control of the emission and reception of the radiation source, scans the object to be measured from multiple angles and at multiple levels, thereby obtaining the internal structure information of the object. In the detection of the bonding strength of the first interface of a solid rocket engine, CT detection can visually display the microscopic structure of the bonding interface between the casing and the insulation layer, including the integrity of the interface, the distribution of the adhesive, and possible defects, etc.

[0006] However, these methods generally have problems such as long detection cycles and limited detection cross-sections. For example, the average time-consuming of DR detection is 8 hours per cross-section, and the missed detection rate of CT detection for weak bonding defects (bonding strength < 0.3 MPa) reaches 40%. Particularly prominent is that with the continuous increase in the size of solid rocket engines in recent years, the cost and coverage problems of the above detection methods have become more significant. In addition, DR detection and CT detection cannot directly provide the specific value of the interface bonding strength and have low sensitivity to hidden defects such as weak bonding of the interface. Summary of the Invention

[0007] The present invention provides an in-situ testing method for the bonding strength of the first interface of a solid rocket motor, which can provide specific values of the bonding strength of the first interface, can identify weak bonding defects where the interface is not delaminated, has a short detection period, is not limited by the detection cross-section, and has a low detection cost.

[0008] The technical solution provided by the present invention is as follows:

[0009] An embodiment of the present invention provides an in-situ testing method for the bonding strength of the first interface of a solid rocket motor, including the following steps:

[0010] After horizontally positioning the housing, perform non-destructive testing on the bottom inner wall of the straight cylinder section, locate the test area that meets the preset conditions, and synchronously obtain the data of the insulation layer thickness.

[0011] Bond a lifting fixture at the center of the test area, and perform a full circumferential annular cutting along the outer contour of the bonding area to isolate the stress of the insulation layer between the bonding area and the non-bonding area.

[0012] Construct a vertical loading system including a fixed pulley set, a flexible rope, and a weight pan. The flexible rope is connected to the lifting fixture and is perpendicular to the bonding area after being tightened.

[0013] Gradually load standard weights until the first interface of the bonding area is peeled off, and record the critical mass parameter in real time.

[0014] Calculate the bonding strength of the first interface based on the critical mass parameter and the area of the bonding area.

[0015] In one embodiment, the preset conditions include: the non-destructive testing waveform conforms to the ASTM E587 amplitude-time domain standard and there is no debonding / delamination signal.

[0016] In one embodiment, the method further includes: before bonding the lifting fixture at the center of the test area, polish the insulation layer of the test area to roughen its surface.

[0017] In one embodiment, the lifting fixture is composed of a bonding substrate and a top rope connecting mechanism, and the bonding area is the fitting area between the bonding substrate and the insulation layer of the test area.

[0018] In one embodiment, the fixed pulley set includes a first fixed pulley and a second fixed pulley, where:

[0019] The first fixed pulley is vertically aligned with the central axis of the lifting fixture;

[0020] The second fixed pulley is arranged on the same horizontal plane as the first fixed pulley;

[0021] The flexible rope passes through the lifting fixture, the first fixed pulley, and the second fixed pulley in sequence, and the terminal is connected to the weight tray; wherein, the flexible rope between the lifting fixture and the first fixed pulley extends in the vertical direction in the tensioned state, while the flexible rope between the first fixed pulley and the second fixed pulley extends in the horizontal direction in the tensioned state.

[0022] In one embodiment, the lifting fixture is bonded to the heat insulation layer of the test area through a room-temperature adhesive.

[0023] In one embodiment, a full circumferential annular cutting is performed along the outer contour of the bonding area, and a cutter with a depth scale is used for the cutting operation, and the cutting direction is kept with a deviation of ≤3° from the normal line of the surface of the heat insulation layer.

[0024] In one embodiment, the method further includes: maintaining static for 20 seconds after each stage of load is applied. If the first interface does not peel during this period, continue to add weights; if the first interface peels during this period, stop adding weights and record the weight of the weights as the critical mass parameter.

[0025] In one embodiment, the method further includes: after recording the critical mass parameter, removing the vertical loading system and repairing the peeled surface.

[0026] In one embodiment, the formula for calculating the bonding strength of the first interface according to the critical mass parameter and the bonding area is: σ = m×g / A bond , where σ represents the bonding strength, m represents the critical mass parameter, g represents the acceleration due to gravity, and A bond represents the bonding area.

[0027] The beneficial effects brought by the technical solutions provided in the embodiments of the present invention include:

[0028] Compared with the detection means for the bonding quality of the shell / heat insulation layer bonding interface such as industrial CT and DR detection, the operation process of the present invention is simple, the cost is low, it can identify the weak bonding defects where the interface is not delaminated, and it can directly give the peeling strength data of the shell / heat insulation layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0030] Figure 1 It is a schematic diagram of the vertical loading system. DETAILED DESCRIPTION

[0031] To enable those skilled in the art to better understand the solution of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] As described in the background art, existing DR detection and CT detection cannot directly provide the specific value of the interface bonding strength and cannot identify the weak bonding defects where the interface is not delaminated. The present invention provides an in-situ testing method for the bonding strength of the first interface of a solid rocket motor, which can identify the weak bonding defects where the interface is not delaminated and can measure the bonding strength of the first interface.

[0033] The handheld ultrasonic flaw detector used in the present invention is a representative device of non-destructive testing technology. It cannot directly obtain the bonding strength of materials and cannot identify the weak bonding defects where the interface is not delaminated. The handheld ultrasonic flaw detector is a portable ultrasonic testing device commonly used in industrial non-destructive testing, which can identify defects inside materials, such as cracks, pores, etc. For the present invention, the handheld ultrasonic flaw detector can detect whether there is debonding and delamination between the insulation layers and between the insulation layer and the composite layer. At the same time, based on the ultrasonic principle, the handheld ultrasonic flaw detector can also determine the thickness of the insulation layer by measuring the time for ultrasonic waves to propagate in the material. For the detection of insulation layer debonding, dual-crystal probes or low-frequency probes (such as 0.5 - 2 MHz) can be used to improve the sensitivity to delamination defects; some devices (such as the USM series) directly feedback the interface bonding state through the synchronous display of the A-scan waveform and the thickness value.

[0034] The present invention first uses a handheld ultrasonic flaw detector to detect whether there is debonding and delamination between the insulation layer and the composite layer, and selects the area without debonding and delamination as the test area; then uses the handheld ultrasonic flaw detector to determine the thickness of the insulation layer in the test area, and then uses a cutter with a depth scale to cut the insulation layer covered by the lifting fixture, physically isolating the insulation layer in the bonding area from the surrounding materials to eliminate the stress interference of the non-bonding area.

[0035] The present invention bonds a lifting fixture in the test area, and then uses a vertical loading system composed of a pulley and a weight to measure the critical mass parameter that causes the failure of the first interface. The bonding strength of the first interface is calculated based on the critical mass parameter and the bonding area. This method accurately simulates the vertical tensile force received by the insulation layer and quantifies the critical tensile force that causes the failure of the first interface. It not only solves the limitations of traditional detection technologies but also can accurately evaluate the interface bonding quality, providing a reliable guarantee for the safety performance of solid rocket motors.

[0036] The in-situ testing method for the bonding strength of the first interface of a solid rocket motor provided by the present invention includes the following steps:

[0037] After horizontally positioning the housing, perform non-destructive testing on the bottom inner wall of the straight cylinder section, locate the test area that meets the preset conditions, and simultaneously obtain the data of the insulation layer thickness;

[0038] Bond a lifting fixture at the center of the test area, and perform a full circumferential annular cutting along the outer contour of the bonding area to isolate the stress of the insulation layer between the bonding area and the non-bonding area;

[0039] Construct a vertical loading system including a fixed pulley set, a flexible rope and a weight pan. The flexible rope is connected to the lifting fixture and is perpendicular to the bonding area after being tightened;

[0040] Gradually load standard weights until the first interface of the bonding area peels off, and record the critical mass parameter in real time;

[0041] Calculate the bonding strength of the first interface based on the critical mass parameter and the area of the bonding area.

[0042] The purpose of horizontally positioning the housing is to ensure the stability of the bonding area and eliminate the influence of gravity on the test results; at the same time, horizontal positioning can also effectively avoid uneven stress distribution caused by the inclination of the housing, ensuring the perpendicularity of the loading force and the accuracy of the test results. Those skilled in the art can use a laser level to calibrate and a hydraulic leveling bracket to achieve the horizontal positioning of the housing.

[0043] The purpose of performing non-destructive testing on the bottom inner wall of the straight cylinder section is to select a horizontal and upward-facing test area at the bottom of the housing to prepare for constructing a vertical loading system.

[0044] The purpose of non-destructive testing is to screen defect-free test areas and exclude interference factors such as debonding / layering; at the same time, non-destructive testing can obtain the data of the insulation layer thickness, providing a basis for the subsequent cutting depth.

[0045] The purpose of bonding the lifting fixture is to connect the vertical loading system to the test area, establish a mechanical conduction interface, and ensure the effective transfer of the load to the bonding area; the purpose of performing a full circumferential annular cutting along the outer contour of the bonding area is to eliminate the boundary effect and avoid the stress interference of the surrounding materials on the insulation layer of the bonding area.

[0046] The purpose of constructing a vertical loading system is to use the gravity of the weights to simulate the vertical tension borne by the insulation layer of the bonding area; the role of the fixed pulley set is to change the direction of the applied force and ensure that the insulation layer of the bonding area can be subjected to a vertical tension.

[0047] The purpose of the graded loading standard weights is to achieve progressive loading to avoid impact effects and accurately capture the critical point of interface failure; the role of recording the critical mass parameter is to quantify the threshold of the failure of Interface I and provide the core input parameter for the calculation of the bonding strength of Interface I.

[0048] The calculation of the bonding strength can convert physical measurement values into engineering strength parameters and provide a quantitative evaluation index for the interface performance.

[0049] In one embodiment, the preset conditions include: the waveform of the non-destructive testing conforms to the ASTM E587 amplitude-time domain standard and there is no debonding / delamination signal. The purpose of setting this preset condition is to ensure the material integrity of the test area and exclude the interference of potential defects on the evaluation of the bonding strength.

[0050] In one embodiment, the method further includes: before bonding the lifting fixture at the center of the test area, grinding the insulation layer of the test area to roughen its surface. The purpose of grinding the surface of the insulation layer is to ensure the bonding effect between the lifting fixture and the insulation layer. The roughness should be controlled within the range of 0.5 - 1.0 μm during the grinding process to maximize the mechanical biting force and chemical bonding force of the bonding surface. A 120-mesh sandpaper can be used for uniform grinding to avoid excessive wear and affect the internal structural performance of the insulation layer.

[0051] In one embodiment, the lifting fixture consists of a bonding substrate and a top rope connection mechanism, and the bonding area is the fitting area between the bonding substrate and the insulation layer of the test area. To ensure the bonding effect between the lifting fixture and the insulation layer, the bonding substrate is preferably made of a flexible sheet to adapt to the slight unevenness of the insulation layer surface, enhance the contact area and adhesion of the bonding surface. The selection of the flexible sheet should consider both strength and toughness to ensure that it does not deform or fall off during the loading process, thus ensuring the accuracy and reliability of the test data. At the same time, the surface of the bonding substrate should be chemically treated to increase its surface activity, promote the effective infiltration and curing of the adhesive, and further improve the bonding strength. The top rope connection mechanism is preferably a metal ring, and the metal ring should have high strength to ensure that it does not break during the loading process.

[0052] In one embodiment, the fixed pulley set includes a first fixed pulley and a second fixed pulley, where: the first fixed pulley is vertically aligned with the central axis of the lifting fixture; the second fixed pulley is arranged on the same horizontal plane as the first fixed pulley; the flexible rope passes through the lifting fixture, the first fixed pulley, and the second fixed pulley in sequence, and the terminal is connected to the weight tray; among them, the flexible rope between the lifting fixture and the first fixed pulley extends vertically in the tensioned state, while the flexible rope between the first fixed pulley and the second fixed pulley extends horizontally in the tensioned state. To ensure that the flexible rope between the first fixed pulley and the second fixed pulley extends horizontally in the tensioned state, the first fixed pulley and the second fixed pulley should be selected with the same specification and model.

[0053] In one embodiment, the lifting fixture is bonded to the thermal insulation layer of the test area through a room-temperature adhesive. By using a room-temperature adhesive, it is possible to ensure that the lifting fixture and the thermal insulation layer can be effectively bonded quickly under room-temperature conditions, thereby significantly improving the test efficiency.

[0054] In one embodiment, a full circumferential annular cut is performed along the outer contour of the bonding area. A cutter with a depth scale is used for the cutting operation. The cutting direction is kept with a deviation of ≤3° from the normal of the surface of the thermal insulation layer, and the cutting depth is set to (H - 0.5) mm (H is the thickness data of the thermal insulation layer) to ensure the cutting accuracy and avoid damaging the composite layer below the thermal insulation layer.

[0055] In one embodiment, the method further includes: maintaining static for 20 seconds after each stage of load is applied. If the first interface does not peel during this period, continue to add weights; if the first interface peels during this period, stop adding weights and record the weight of the weights as the critical mass parameter. To determine whether the first interface peels, it can be observed with the naked eye or monitored using non-destructive testing techniques.

[0056] In one embodiment, the method further includes: after recording the critical mass parameter, removing the vertical loading system and repairing the peeled surface. After the test, paste the thermal insulation layer on the exposed composite layer to restore the integrity of the thermal insulation layer and ensure that the thermal protection performance of the test area is not affected.

[0057] In one embodiment, the formula for calculating the bonding strength of the first interface obtained according to the critical mass parameter and the bonding area is: σ = m×g / A bond , where σ represents the bonding strength, m represents the critical mass parameter, g represents the acceleration due to gravity, and A bond represents the bonding area. This calculation method is simple. Through this method, the bonding effect can be accurately evaluated, providing reliable data support for subsequent process optimization and ensuring the stable quality of the product.

[0058] In one embodiment, the bonding area is 10mm * 10mm or Φ10mm. The peeled thermal insulation layer is very small and will not affect the overall thermal insulation effect after repair. Moreover, the repair process is simple and only requires a small amount of adhesive to complete, significantly reducing the maintenance cost.

[0059] The technical solution of the present invention is described in detail below through specific embodiments:

[0060] Example 1

[0061] An in-situ test method for the bonding strength of the first interface of a solid rocket motor sequentially performs the following steps:

[0062] Step 1: Specimen pretreatment

[0063] Horizontally fix the cured housing on the shock-proof platform, clean the inner surface of the thermal insulation layer with anhydrous ethanol, and let it dry naturally.

[0064] Step 2: Nondestructive testing and area calibration

[0065] 1. Select test points on the thermal insulation layer at the bottom of the straight cylinder section of the housing.

[0066] 2. Use a handheld ultrasonic flaw detector (center frequency 5 MHz) to detect the marked area. Select the area where the nondestructive testing waveform conforms to the ASTM E587 amplitude-time domain standard and there is no debonding / delamination signal as the test area, and use the handheld ultrasonic flaw detector to obtain the thermal insulation layer thickness data H (accuracy ±0.1 mm) of the test area.

[0067] Step 3: Surface treatment

[0068] 1. Use 120-mesh sandpaper to polish the test area to make the surface roughness Ra 0.5 - 1.0 μm.

[0069] 2. After secondary cleaning, dry it until there is no dust on the surface.

[0070] Step 4: Tooling bonding

[0071] 1. Bond the lifting fixture to the polished test area through a room-temperature adhesive (Araldite 2015); as Figure 1 shown, the lifting fixture consists of a bonding substrate (Φ10 mm) and a top rope connection mechanism;

[0072] 2. Control the environmental humidity at 40% - 60% for room-temperature curing.

[0073] Step 5: Interface isolation cutting

[0074] Use a cutter with a depth scale to perform a full circumferential annular cut along the outer contour line of the lifting fixture; set the cutting depth to (H - 0.5) mm, and the tool feed speed ≤ 2 mm / s; observe the color change of the cut mark in real time to avoid damaging the composite layer of the housing.

[0075] Step 6: Construct a vertical loading system

[0076] Construct a vertical loading system including a fixed pulley set, a flexible rope, and a weight tray above the lifting fixture. As Figure 1 shown, the fixed pulley set includes a first fixed pulley and a second fixed pulley, where: the first fixed pulley is vertically aligned with the central axis of the lifting fixture (deviation ≤ 1 mm); the second fixed pulley is arranged on the same horizontal plane as the first fixed pulley; the flexible rope passes through the lifting fixture, the first fixed pulley, and the second fixed pulley in sequence, and the terminal is connected to the weight tray; the vertical height from the bottom of the weight tray to the surface of the thermal insulation layer is 80 ± 30 mm.

[0077] Step 7: Step Loading Test

[0078] Add standard weights step by step in a 0.5 kN gradient, and keep each load level for 20 seconds. Monitor using non-destructive testing technology. If the non-destructive testing waveform conforms to the ASTM E587 amplitude-time domain standard and there is no debonding / delamination signal, it proves that no peeling occurs at the first interface, then continue to add weights; if peeling occurs at the first interface during this period, stop adding weights and record the weight of the weights as the critical mass parameter. Visual appearance inspection + manual pressing inspection can also be used to replace the monitoring of non-destructive testing technology.

[0079] Step 8: Damage Repair

[0080] Use the supporting repair agent (model EP-302) to fill the peeled area of the thermal insulation layer, and the deviation of the repair thickness from the original layer is ≤ 0.2 mm.

[0081] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present invention. Unless otherwise clearly specified and defined, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0082] It should be noted that in the present invention, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the element.

[0083] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features invented herein.

Claims

1. A method for in-situ testing of the first interface bonding strength of a solid rocket engine, characterized in that: The following steps are involved: After the shell is positioned horizontally, nondestructive testing is performed on the bottom of the inner wall of the straight tube section to locate the test area that meets the preset conditions and simultaneously obtain the insulation layer thickness data; Bonding a hoisting fixture at the center of the test area, and performing full-circumferential annular cutting along the outer contour of the bonding area to isolate the insulation layer stress of the bonding area from that of the non-bonding area; Constructing a vertical loading system including a fixed pulley block, a flexible rope and a weight plate, wherein the flexible rope is connected to the lifting fixture and is perpendicular to the bonding area after being tightened; Standard weights are loaded in stages until the first interface of the bonding area peels off, and critical mass parameters are recorded in real time; The first interface bonding strength is obtained by calculation based on the critical mass parameter and the bonding area.

2. The solid rocket engine first interface bonding strength in-situ testing method according to claim 1, characterized in that: The preset conditions include: the non-destructive testing waveform complies with the ASTM E587 amplitude-time domain standard and has no debonding / delamination signal.

3. The solid rocket engine first interface bonding strength in-situ testing method according to claim 1, characterized in that: The method further comprises: before bonding the hoisting fixture at the center of the test area, grinding the insulation layer of the test area to roughen its surface.

4. The solid rocket engine first interface bonding strength in-situ testing method according to claim 1, characterized in that: The hoisting fixture is composed of a bonding substrate and a top rope connection mechanism, and the bonding area is a fitting area between the bonding substrate and the thermal insulation layer of the test area.

5. The solid rocket engine first interface bonding strength in-situ testing method according to claim 1 or 4, characterized in that: The fixed pulley assembly comprises a first fixed pulley and a second fixed pulley, wherein: The first fixed pulley is vertically aligned with the central axis of the lifting fixture; The second fixed pulley is arranged in the same horizontal plane as the first fixed pulley; The flexible rope passes through the lifting fixture, the first fixed pulley and the second fixed pulley in sequence, and the terminal end is connected to the weight plate; wherein, the flexible rope between the lifting fixture and the first fixed pulley extends in the vertical direction under the tension state, and the flexible rope between the first fixed pulley and the second fixed pulley extends in the horizontal direction under the tension state.

6. The solid rocket engine first interface bonding strength in-situ testing method according to claim 1, characterized in that: The hoisting fixture is bonded to the insulation layer of the test area by a room temperature adhesive.

7. The solid rocket motor first interface bonding strength in-situ testing method according to claim 1, characterized in that: A full-circumferential annular cutting is performed along the outer contour of the bonding area, and a cutting knife with a depth scale is used to perform the cutting operation, and the cutting direction is maintained to have a deviation of ≤3° from the normal line of the surface of the thermal insulation layer.

8. The solid rocket motor first interface bonding strength in-situ testing method according to claim 1, characterized in that: The method also includes: maintaining stillness for 20 seconds after each level of load is applied, and if the first interface does not peel off during this period, continuing to add weights; if the first interface peels off during this period, stopping adding weights, and recording the weights as the critical mass parameter.

9. The solid rocket motor first interface bonding strength in-situ testing method according to claim 1, characterized in that: The method further includes removing the vertical loading system and repairing the peeled surface after recording the critical mass parameter.

10. The solid rocket engine first interface bonding strength in-situ testing method according to claim 1, characterized in that: The formula for calculating the first interface bonding strength based on the critical mass parameter and the bonding area is: σ = m × g / A bond , where σ represents the bonding strength, m represents the critical mass parameter, g represents the gravitational acceleration, and A bond Represents the bonding area.

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