CN112373738B - Thin-wall structure vibration test device and method considering pressure difference condition - Google Patents

Abstract

The invention relates to a thin-walled structure vibration test device and a test method taking into account pressure difference conditions, and belongs to the technical field of spacecraft structural product vibration test. The thin-walled structure is a part of the spacecraft cabin, and the thin-walled structure is a circular plate, and the thickness of the circular plate is not more than 15mm, preferably 15mm. The device can realize the vibration test of the thin-walled structure and simultaneously realize the comprehensive loading of the thin-walled structure under pressure difference. It is always in a tight fit state, and the pressure differential conditions are applied evenly and stably; at the same time, the flexible structure of the airbag makes the device have a certain universal type, which is suitable for various spacecraft thin-walled structures with combined pressure differential and vibration conditions vibration test; the test method is simple, reliable and versatile.

Description

A kind of thin-walled structure vibration test device and test method taking into account differential pressure conditions

technical field

The invention relates to a thin-walled structure vibration test device and a test method taking into account pressure difference conditions, and belongs to the technical field of spacecraft structural product vibration test. The thin-walled structure is a part of the spacecraft cabin, and the thin-walled structure is a circular plate, and the thickness of the circular plate is not more than 15mm, preferably 15mm.

Background technique

In recent years, with the continuous development of aerospace technology, parachute recovery and landing systems have been used in various aircraft such as manned space vehicle return capsules, reusable returnable satellite return capsules, deep space probes, and strategic and tactical weapon data modules. widely used. A key component used in conjunction with the parachute recovery and landing system is a thin-walled structure. Its function is to maintain the integrity of the shape of the aircraft during flight, and to avoid the parachute system from contacting high-temperature airflow. The parachute recovery and landing system can achieve reliable operation during operation. Separation opens the exit channel for the parachute. Most of the thin-walled structures are wall plate structures, using light and low-strength materials such as aluminum alloy, honeycomb panel sandwich structure, and carbon fiber.

Since one side of the thin-walled structure is exposed to the outer surface of the aircraft, and the other side faces the inside of the aircraft, there will be a pressure difference between the inside and outside of the thin-walled structure during the take-off or re-entry section of the aircraft. Vibration tests are widely used as a method to measure the ability of thin-walled structures to withstand mechanical loads during flight. At this stage, the existence of pressure difference is not considered in the vibration test of thin-walled structures. This test method can only realize the test conditions of thin-walled structures under a single vibration test condition, and cannot truly verify the combination of pressure difference and vibration. There are certain limitations in the performance evaluation of thin-walled structures subjected to mechanical environmental tests.

As a flexible structure used in the landing buffer field, the airbag has the advantages of simple and reliable structure, low cost, reusability, foldable storage, and small installation volume. The return cabin and other fields have been widely used. Since the airbag is made of flexible materials, it can be closely fitted with different structural surfaces after being inflated, and the adaptability is good.

In view of the problem that the pressure difference + vibration comprehensive working condition test verification cannot be realized in the current thin-walled structure vibration test, the present invention will combine the advantages of the above-mentioned airbag structure to invent a thin-walled structure vibration test device and test method that take into account the pressure difference conditions. It can realize the comprehensive loading of pressure difference and vibration conditions on the thin-walled structure, and provide a new and efficient test method for the comprehensive vibration test of the thin-walled structure of the spacecraft.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a thin-walled structure vibration test device and a test method that take into account the differential pressure conditions, which are used to load the thin-walled structure of the aircraft under the condition of differential pressure and the comprehensive working conditions of differential pressure and vibration. . At present, thin-walled structures can only perform a single test under vibration conditions, and numerical simulations can only be used for the mechanical environment tolerance under the condition of pressure difference, which cannot truly verify the actual working conditions of thin-walled structures. The device has a simple structure, is convenient to install and debug, adopts the flexible structure of the airbag to ensure close fit with the thin-walled structure, and has high differential pressure loading accuracy. It provides an efficient solution for applying differential pressure composite loads during vibration testing of thin-walled structures.

The present invention is a thin-walled structure vibration test device that takes into account pressure differential conditions, the device is composed of two parts, a mechanical fixing platform and a differential pressure loading system;

The mechanical fixing platform is installed on the installation surface of the vibration test bench, and includes a fixed pressure plate and a first fixed hook and loop. The positional relationship is that the lower end surface of the fixed pressure plate is connected with the mounting surface of the vibration test bench by bolts, and the upper surface of the fixed pressure plate and the thin-walled structure are also connected by bolts. installation interface. The fixed pressure plate is made of steel (45#) or aluminum (2A12) material, and the type and quantity of the installation interface with the thin-walled structure can be adaptively designed according to the thin-walled structure. The first fixing hook is made of nylon material, and the size, bonding quantity and bonding position of the first fixing hook can be adaptively designed with the differential pressure loading system.

The differential pressure loading system includes a differential pressure airbag module and a pressurizing module. The positional connection relationship is as follows: the differential pressure airbag module is arranged between the mechanical fixing platform and the thin-walled structure, and is used to apply a constant pressure in a fixed direction to the thin-walled structure; The module inflates and maintains the internal pressure of the differential pressure bladder module constant.

The differential pressure airbag module is composed of an intake valve, an exhaust valve, a pad cloth, an inflation tube, a fixed buckle, an upper end surface of the airbag, a lower end surface of the airbag, a side surface of the airbag, an upper fixed velcro, a lower fixed velcro, and a second fixed velcro. Airbag flexible structure composed of Velcro. The intake valve is a commercially available part. The intake valve passes through the installation hole of the inflatable tube and the inflatable tube is pressurized into one by means of an adhesive, and is connected and fixed by a nut. The connection part is locally strengthened; the intake valve can control the inflation air volume of the differential pressure airbag module, and inflate the differential pressure airbag module in one direction. It has a reverse sealing function; the exhaust valve is also a commercially available part, and the installation position is on the opposite side of the intake valve. The exhaust valve passes through the installation hole of the inflatable pipe and the inflatable pipe is pressurized into one by adhesive and fixed by a nut connection , between the nut, the inflation pipe and the exhaust valve, the connection part is locally strengthened by the gasket; the exhaust valve is used to empty the air volume of the differential pressure airbag module after the test; the gasket is 0.1mm thick FST1003TPU film; the inflatable tube is the connection device between the differential pressure airbag module and the pressurizing module, and is the inflation interface of the differential pressure airbag module. The shape of the inflatable tube is a flat tube structure, and the material is 210D Oxford cloth. In order to ensure sufficient safety distance between the differential pressure airbag module and the pressurization module, the length of the inflatable tube is generally ≥5m; the inflatable tube is heat-sealed every 1m. A fixed buckle The loop is used to fix the inflatable tube. The purpose is to prevent the inflatable tube from falling after inflation. The shape of the fixed loop is a rectangular structure of 20mm × 50mm, and the material is 210D Oxford cloth. A thin cylindrical sealing structure together forms the core module of the differential pressure airbag module; the shape of the upper end surface of the airbag and the lower end surface of the airbag are disc-shaped; the shape of the side surface of the airbag is a strip-shaped strip; The upper end surface of the airbag, the lower end surface of the airbag and the side surface of the airbag are all made of 210D Oxford cloth; the dimensions of the upper end surface of the airbag, the lower end surface of the airbag and the side surface of the airbag can be adapted to the specific shape of the thin-walled structure; the upper fixed adhesive The buckle is bonded to the outer side of the upper end face of the airbag. As the installation interface with the thin-walled structure, the upper fixed velcro is made of nylon material. The size, bonding quantity and bonding position of the upper fixed velcro can be adapted to the specific shape of the thin-walled structure. flexible design; the lower fixed velcro is bonded to the outer side of the lower end face of the airbag, as an installation interface with the mechanical fixing platform, and is installed corresponding to the first fixed velcro, the lower fixed velcro is made of nylon material, and the lower fixed velcro is The size, bonding quantity, and bonding position correspond to the first fixed velcro; the second fixed velcro is bonded to the thin-walled structure as an installation interface between the thin-walled structure and the differential pressure airbag module, and is connected with the The upper fixed velcro is installed correspondingly, the second fixed velcro is made of nylon material, and the size, bonding quantity and bonding position of the second fixed velcro are corresponding to the upper fixed velcro.

The pressurizing module includes a high-pressure gas cylinder, a monitoring pressure gauge, an exhaust port, and an exhaust pipeline, all of which are commercially available products. The positional connection relationship is as follows: the outlet of the high-pressure gas cylinder is connected to an external exhaust pipe, and the exhaust port is installed at the end of the exhaust pipe and is screwed with the intake valve to inflate the differential pressure airbag module; The gas port can control the exhaust volume of the high-pressure gas cylinder to avoid damage to the differential pressure airbag module caused by overshoot when the high-pressure gas cylinder is exhausted; the monitoring pressure gauge is installed between the gas outlet and the exhaust port of the high-pressure gas cylinder. The internal pressure of the differential pressure airbag module is monitored for follow-up control of the inflation pressure of the differential pressure airbag module.

Wherein, the number of the fixed pressing plate is 1 set, and the number of the first fixed hook and loop needs to be designed.

Among them, the number of intake valves is 1 set; the number of pads is 2 sets; the number of inflation tubes is 1 set; the number of fixed buckles is determined by the length of the inflation tube; The quantity of the end face is 1 set; the quantity of the airbag side is 1 set; the quantity of the upper fixing velcro needs to be designed; the quantity of the lower fixing velcro is equal to the number of the first fixing velcro.

Among them, the number of high-pressure gas cylinders is 1 set; the number of monitoring pressure gauges is 1 set; the number of exhaust valves is 1 set; the number of exhaust pipes is 1 set.

(2) a kind of thin-walled structure vibration test method of the present invention taking into account the differential pressure conditions, the concrete steps of the method are as follows:

Step 1: Clamping of the mechanical fixed platform: Fix the mechanical fixed platform on the installation surface of the vibration test bench to complete the connection between the mechanical fixed platform and the vibration test bench.

Step 2: Installation and initialization of the pressurization module: confirm the high-pressure gas cylinder at best, complete the installation of the high-pressure gas cylinder, exhaust pipeline, monitoring pressure gauge and exhaust port, and check and confirm the installation status of the pressurization module; The high-pressure gas cylinder and the exhaust port are closed, and the monitoring pressure gauge is the initial zero position.

Step 3: Check the status of the differential pressure airbag module: Check whether the upper end face of the airbag, the lower end face of the airbag, and the side of the airbag are worn or not in the differential pressure airbag module, and confirm the intake valve, exhaust valve, inflation pipe, upper fixed velcro and lower fixed The installation state of the hook and loop; at this time, the intake valve and exhaust valve are closed, and the differential pressure module is not inflated.

Step 4: Check the air tightness of the differential pressure loading system: Connect the exhaust port of the pressurization module to the intake valve of the differential pressure airbag module to complete the installation of the differential pressure loading system; open the exhaust port and intake valve, and exhaust the air. The valve is closed; finally, open the high-pressure gas cylinder, charge 10% of the target pressure into the differential pressure air bag module, close the high-pressure gas cylinder, keep the pressure for 5 minutes, and monitor the pressure value of the differential pressure loading system in real time by monitoring the pressure gauge, 5 minutes If the pressure displayed by the monitoring pressure gauge is within ±5% of the charging pressure, it indicates that the differential pressure loading system is airtight; if the pressure displayed by the monitoring pressure gauge exceeds ±5% of the charging pressure, open the exhaust valve to discharge Check the air volume of the air pressure differential loading system, and confirm each connection link of the differential pressure loading system one by one, and then repeat the above steps to re-check the air tightness of the differential pressure loading system until the air tightness of the differential pressure loading system meets the requirements.

Step 5: Installation of the mechanical fixing platform and the differential pressure loading system: Connect the differential pressure airbag module to the first fixing velcro of the mechanical fixing platform through the lower fixing velcro to complete the installation of the mechanical fixing platform and the differential pressure loading system. At this time, the high-pressure gas cylinder, exhaust port, intake valve, and exhaust valve are in a closed state, the detection pressure gauge is at the initial zero position, and the differential pressure airbag module is in an uninflated state.

Step 6: Installation of the thin-walled structure and the differential pressure loading system: Paste the same number of second velcros on the thin-walled structure at the corresponding positions where the upper velcro is bonded, and connect the thin-walled structure with the second velcro through the second velcro. The upper fixed velcro is bonded to realize the installation with the differential pressure loading system; finally, the thin-walled structure and the fixed pressure plate are screwed together.

Step 7: Pressurization of thin-walled structure: First open the exhaust port and intake valve, the exhaust valve is closed, and the detection pressure gauge is the initial zero position. Open the high-pressure gas cylinder, fill the target pressure gas volume into the differential pressure air bag module, and monitor the pressure value in real time by monitoring the pressure gauge. When the pressure value reaches the target pressure, close the high-pressure gas cylinder and keep the pressure for 5 minutes. When the monitoring pressure gauge displays The vibration test is started when the monitored pressure value of is in a steady state and within ±5% of the target pressure.

Step 8: Conduct a vibration test. Start the vibration test bench and conduct vibration tests on thin-walled structures according to the given vibration test conditions.

The implementation process of the thin-walled structure vibration test taking into account the differential pressure conditions needs to be carried out according to the above steps.

beneficial effect

Compared with the prior art, a thin-walled structure vibration test device and a test method that take into account the differential pressure conditions of the present invention have the following beneficial effects:

The device can realize the vibration test of the thin-walled structure and simultaneously realize the comprehensive loading of the thin-walled structure under the pressure difference, and can apply the actual comprehensive working conditions of the thin-walled structure of the spacecraft in the take-off section or the re-entry section, which improves the current situation. The accuracy of mechanical performance verification of spacecraft thin-walled structure vibration test;

The device conducts the thin-walled structure vibration test taking into account the pressure difference condition, which improves the authenticity and reliability of the mechanical properties of the thin-walled structure vibration test, and provides a real test result comparison for numerical simulation.

The device uses the airbag flexible structure as the carrier for applying pressure differential conditions, which can ensure that the thin-walled structure is always in close contact with the thin-walled structure during the test process, and the pressure differential conditions are applied uniformly and stably. A certain general type, suitable for vibration test of various spacecraft thin-walled structures with combined pressure differential and vibration conditions; the test method is simple, reliable, and versatile.

Description of drawings

Figure 1 is a schematic structural diagram of a mechanically fixed platform;

2 is a schematic diagram of a three-dimensional structure of a differential pressure airbag module;

3 is a schematic diagram of a plane structure of a differential pressure airbag module;

Figure 4 is a schematic diagram of the overall installation of the pressurization module and the test device;

1-Fixed pressure plate, 2-Fixed hook and loop fastener, 3-Inlet valve, 4-Exhaust valve, 5-Pad cloth, 6-Inflatable tube, 7-Fixed loop, 8-Airbag upper end face, 9-Top Fixed Velcro, 10-Second Fixed Velcro, 11-Airbag Side, 12-Airbag Bottom Surface, 13-Lower Fixed Velcro, 14-High Pressure Gas Cylinder, 15-Monitoring Pressure Gauge, 16-Exhaust Port, 17- exhaust line.

Detailed ways

Below in conjunction with the accompanying drawings, the specific embodiments of the present invention will be described with a specific flat-plate thin-walled structure:

The present invention is a thin-walled structure vibration test device that takes into account pressure differential conditions. The device is composed of two parts: a mechanical fixing platform and a differential pressure loading system.

The schematic diagram of the structure of the mechanically fixed platform is shown in Figure 1. The mechanical fixing platform consists of a fixed pressure plate 1 and a first fixed hook and loop fastener 2 . The fixed pressure plate 1 is fixed on the installation surface of the vibration test bench by screws. The fixed pressure plate 1 is machined with 8 cylindrical structures and has mounting threaded holes for thin-walled structures; There are 6 first fixing hooks 2, the first fixing hooks 2 and the fixed pressing plate 1 are bonded by adhesive, and the 6 first fixing hooks 2 are installation interfaces with the differential pressure loading system. The fixed pressing plate 1 is a square plate structure made of aluminum (2A12), and the first fixed hook and loop fastener 2 is made of nylon material, and the size is 40mm×25mm×0.5mm.

The differential pressure loading system consists of a differential pressure airbag module and a pressurizing module.

As shown in Figure 2, the differential pressure airbag module is a flexible structure of the airbag, consisting of an intake valve 3, an exhaust valve 4, a pad 5, an inflation tube 6, a fixed buckle 7, an upper end surface of the airbag 8, an upper fixed hook and loop 9, The side surface of the airbag 11 , the lower end surface of the airbag 12 , the lower fixed velcro 13 and the second fixed velcro 10 are composed.

As shown in FIG. 3 , the intake valve 3 and the exhaust valve 4 are arranged in a mirror image at the end of the charging pipe 6 . The intake valve 3 and the exhaust valve 4 respectively pass through the mounting holes on the charging pipe 6 Use nuts to tighten, and pass 1 piece between the intake valve 3 and the charging pipe 6, between the intake valve 3 and the tightening nut, between the exhaust valve 4 and the charging pipe 6, and between the exhaust valve 4 and the tightening nut The pad cloth 5 is partially reinforced. The pad cloth 5 is a FST1003TPU film with a thickness of 0.1mm; the inflatable tube 6 is heat-sealed with the side 11 of the airbag, and adopts a flat tube-shaped structure with a length of 5m and a thickness of about 40mm. Five fixed buckles 7 are heat-sealed to fix the inflation tube 6. The material of the fixed buckles 7 is 210D Oxford cloth; the upper end surface of the airbag 8, the side surface of the airbag 11, and the lower end surface of the airbag 12 are heat-sealed into a diameter of 0.55m and a thickness of about 70mm cylindrical sealing structure, the upper end surface 8 of the airbag, the side surface 11 of the airbag, and the lower end surface 12 of the airbag are all made of 210D Oxford cloth; the upper end surface 8 of the airbag is uniformly bonded along the circumference of 430mm in diameter. The fixed hook 9 and the upper end face 8 of the airbag are bonded by an adhesive, the six upper fixed hooks 9 are the installation interfaces with the thin-walled structure, the upper fixed hook 9 is made of nylon material, and the size is 40mm×25mm×0.5mm; On the wall structure, there are 6 second fixing velcros 10 evenly distributed at the same position as the 6 upper fixing velcros 9, which are used to connect the thin-walled structure with the differential pressure airbag module. The second fixing velcros 10 are made of nylon and have a size of 40mm. ×25mm×0.5mm; 6 lower fixing hooks 13 are evenly distributed on the lower end surface 12 of the airbag along the circumference of 430mm in diameter, and used together with the 6 first fixing hooks 2 to realize the connection between the differential pressure airbag module and the mechanical fixing platform connect.

As shown in FIG. 4 , the high-pressure gas cylinder 14 in the pressurization module is fixed on the ground, the exhaust line 17 is connected from the outlet of the high-pressure gas cylinder 14 , and the monitoring pressure gauge 15 is screwed on the outlet of the high-pressure gas cylinder 14 and the exhaust port. Between the air ports 16, the inflation pressure is monitored; the exhaust port 16 is screwed with the intake valve 3 to realize the connection between the pressurizing module and the differential pressure airbag module.

In this embodiment, the inflation pressure of the high-pressure gas cylinder 14 is 5 MPa to 12 MPa.

As shown in Figure 4, the present invention is a thin-walled structure vibration test method that takes into account differential pressure conditions. The specific steps of the method are as follows:

Step 1: Clamping of the mechanical fixing platform: Fix the fixing pressure plate 1 to which the first fixing hook and loop 2 is bonded on the installation surface of the vibration test bench by screws to complete the connection between the mechanical fixing platform and the vibration test bench.

Step 2: Installation and initialization of the pressurization module: the high-pressure gas cylinder 14 is full, and one end of the exhaust pipe 17 is screwed to the outlet of the high-pressure gas cylinder 14, and then the monitoring pressure gauge 15 and the exhaust pipe 17 are screwed together. , screw the exhaust port 16 on the end of the exhaust pipe 17 to straighten the exhaust pipe 17 . Close the air outlet and exhaust port 16 of the high-pressure gas cylinder 14, and monitor the pressure gauge 15 to reset to zero for initialization.

Step 3: Check the status of the differential pressure air bag module: Check whether the upper end face 8 of the air bag, the lower end face 12 of the air bag, and the side surface 11 of the air bag are worn or not. The buckle 9 and the lower fixed velcro 13 are respectively bonded to the upper end surface 8 of the airbag and the lower end surface 12 of the airbag; the intake valve 3 and the exhaust valve 4 are closed, and the differential pressure module is in an uninflated state.

Step 4: Check the air tightness of the differential pressure loading system: screw the exhaust port 16 and the intake valve 3; open the exhaust port 16 and the intake valve 3, close the exhaust valve 4; Fill the differential pressure air bag module with 1kPa air, close the air outlet of the high-pressure gas cylinder, keep the pressure for 5 minutes, and read the pressure value of the pressure gauge 15. If the pressure displayed by the monitoring pressure gauge 15 is within ±0.05kPa, it indicates that the differential pressure is loaded. The air tightness of the system is good; if the pressure displayed by the monitoring pressure gauge 15 is outside ±0.05kPa, open the exhaust valve 4 to evacuate the air volume of the differential pressure loading system, and confirm each connection link of the differential pressure loading system one by one, repeat In the above steps, check the air tightness of the differential pressure loading system again until the air tightness of the differential pressure loading system meets the requirements.

Step 5: Installation of the mechanical fixing platform and the differential pressure loading system: Connect the lower fixing hook 13 to the first fixing hook 2 to complete the installation of the mechanical fixing platform and the differential pressure loading system. Close the high-pressure gas cylinder 14 , the exhaust port 16 , the intake valve 3 , and the exhaust valve 4 , monitor the pressure gauge 15 to zero for initialization, and the differential pressure module is in an uninflated state.

Step 6: The installation of the thin-walled structure and the differential pressure loading system: 6 second fixing hooks 10 are bonded on the thin-walled structure, and the bonding position of the second fixing hooks 10 is the same as that of the upper fixing hooks 9; Adhere the second fixing hook 10 to the upper fixing hook 9 to complete the installation of the thin-walled structure and the differential pressure loading system; then install the thin-walled structure on the 8 cylindrical structures on the fixed pressure plate 1 through 8 mounting screws .

Step 7: Pressurizing the thin-walled structure: first open the exhaust port 16, the intake valve 3, close the exhaust valve 4, monitor the pressure gauge 15 to zero for initialization; open the high-pressure gas cylinder 14, and charge the differential pressure airbag module The gas volume is 10kPa, and the pressure value is monitored in real time by monitoring the pressure gauge 15. When the pressure value reaches 10kPa, the high-pressure gas cylinder 14 is closed, and the pressure is maintained for 5 minutes. When the pressure value is in a stable state and within the range of ±0.5kPa, start the vibration test .

Step 8: Conduct a vibration test. Start the vibration test bench and conduct vibration tests on thin-walled structures according to the given vibration test conditions.

A thin-walled structure vibration test device and a test method that take into account pressure differential conditions. By combining a traditional single vibration test device for a spacecraft thin-walled structure with a flexible structure of an airbag, the combined work of performing pressure differential and vibration tests on a thin-walled structure is realized. It improves the authenticity and accuracy of verifying the mechanical properties of the take-off section or re-entry section of the thin-walled structure of the spacecraft, and can reversely correct the numerical model of the simulation;

Based on the coupling design of the flexible structure of the airbag, the uniform and stable loading of the thin-walled structure is realized; at the same time, the adaptability and versatility of the test device are broadened, and the designability is strong. A vibration test of a thin-walled structure of a spacecraft; the vibration test method of the thin-walled structure is simple, reliable, and versatile.

Claims (9)

1. a thin-walled structure vibration test device that takes into account differential pressure conditions, is characterized in that: this test device comprises a mechanical fixing platform and a differential pressure loading system; The mechanical fixing platform is installed on the installation surface of the vibration test bench. The mechanical fixing platform includes a fixed pressure plate and a first fixed hook and loop. The lower end surface of the fixed pressure plate and the installation surface of the vibration test bench are connected by bolts. The wall structure is connected by bolts; the first fixed velcro is bonded to the fixed pressure plate as an installation interface with the differential pressure loading system; The differential pressure loading system includes a differential pressure airbag module and a pressurizing module, the differential pressure airbag module is arranged between the mechanical fixing platform and the thin-walled structure, and is used to apply a constant pressure in a fixed direction to the thin-walled structure; the pressurizing module Connected with the differential pressure airbag module to inflate the differential pressure airbag module and maintain the internal pressure of the differential pressure airbag module constant; The pressure differential airbag module is a flexible structure of the airbag, including an intake valve, an exhaust valve, a pad, an inflation tube, a fixed buckle, an upper end surface of the airbag, a lower end surface of the airbag, a side surface of the airbag, an upper fixed velcro and a lower fixed Velcro and second fixed Velcro; The intake valve passes through the installation hole of the inflatable pipe and the inflatable pipe is pressurized into one by the adhesive, and is connected and fixed by the nut, and the connection part is locally strengthened by the pad cloth between the nut, the inflatable pipe and the intake valve; The air intake valve can control the inflation gas volume of the differential pressure airbag module, and inflate the differential pressure airbag module in one direction. After the inflation is completed, the high-pressure gas cannot be discharged through the intake valve, and the differential pressure airbag module has a reverse sealing function; The installation position of the exhaust valve is on the opposite side of the intake valve. The exhaust valve passes through the installation hole of the inflatable pipe and the inflatable pipe is pressurized as a whole and fixed by a nut. The connection parts are locally strengthened by the pad cloth; the exhaust valve is used to empty the air volume of the differential pressure airbag module after the test; The inflatable tube is the connection device between the differential pressure airbag module and the pressurizing module, and is the inflating interface of the differential pressure airbag module. , the upper end surface of the airbag, the lower end surface of the airbag, and the side surface of the airbag are thermally synthesized into a thin cylindrical sealing structure, the shape of the upper end surface of the airbag and the lower end surface of the airbag are disc-shaped, and the shape of the side surface of the airbag is a sheet-like strip; The upper fixed velcro is bonded to the outer side of the upper end face of the airbag as an installation interface with the thin-walled structure, and the lower fixed velcro is bonded to the outer side of the lower end face of the airbag as an installation interface with the mechanical fixing platform. The second fixed velcro It is bonded to the thin-walled structure and used as the installation interface between the thin-walled structure and the differential pressure airbag module. 2 . The thin-walled structure vibration test device according to claim 1 , wherein the fixed pressure plate is made of 45# steel or 2A12 aluminum. 3 . 3 . The thin-walled structure vibration test device according to claim 1 , wherein the first fixed hook and loop fastener is made of nylon material. 4 . 4 . The thin-walled structure vibration test device according to claim 1 , wherein the underlay is a FST1003TPU film with a thickness of 0.1 mm. 5 . 5. The thin-walled structure vibration test device according to claim 1, characterized in that: the shape of the inflatable tube is a flat tube-shaped structure, the material is 210D Oxford cloth, and the length of the inflatable tube is ≥5m, a fixed loop is heat-sealed every 1m on the inflatable tube to fix the inflatable tube. 6 . The thin-walled structure vibration test device according to claim 1 , wherein the shape of the fixed buckle is a 20mm×50mm rectangular structure, and the material is 210D Oxford cloth. 7 . 7 . The thin-walled structure vibration test device according to claim 1 , wherein the upper end surface of the airbag, the lower end surface of the airbag and the side surface of the airbag are all made of 210D Oxford cloth. 8 . 8 . The thin-walled structure vibration test device according to claim 1 , wherein the pressurization module comprises a high-pressure gas cylinder, a monitoring pressure gauge, an exhaust port and an exhaust pipeline. 9 . , the outlet of the high-pressure gas cylinder is connected to an external exhaust pipe, and the exhaust port is installed at the end of the exhaust pipe and is screwed with the intake valve to inflate the differential pressure airbag module; the exhaust port can be used to inflate the high-pressure gas cylinder. The monitoring pressure gauge is installed between the air outlet and the exhaust port of the high-pressure gas cylinder to monitor the internal pressure of the differential pressure airbag module in real time, which is used for follow-up control of the inflation pressure of the differential pressure airbag module. 9. A thin-walled structure vibration test method taking into account differential pressure conditions, characterized in that the steps include: Step 1: Fix the mechanical fixing platform on the installation surface of the vibration test bench to complete the connection between the mechanical fixing platform and the vibration test bench; Step 2: Confirm the capacity of the high-pressure gas cylinder at best, complete the installation of the high-pressure gas cylinder, the exhaust pipeline, the monitoring pressure gauge and the exhaust port, and check and confirm the installation status of the pressurization module; at this time, the high-pressure gas cylinder and the exhaust port are in In the closed state, the monitoring pressure gauge is the initial zero position; Step 3: Check whether the upper end face of the air bag, the lower end face of the air bag, and the side of the air bag in the differential pressure air bag module are worn or not, and confirm the installation status of the intake valve, exhaust valve, inflation pipe, upper fixed velcro and lower fixed velcro; The intake valve and exhaust valve are closed, and the differential pressure module is not inflated; Step 4: Check the airtightness of the differential pressure loading system: connect the exhaust port of the pressurization module to the intake valve of the differential pressure airbag module to complete the installation of the differential pressure loading system; open the exhaust port and the intake valve to exhaust the air The valve is closed; finally, open the high-pressure gas cylinder, charge 10% of the target pressure into the differential pressure air bag module, close the high-pressure gas cylinder, keep the pressure for 5 minutes, and monitor the pressure value of the differential pressure loading system in real time by monitoring the pressure gauge, 5 minutes If the pressure displayed by the monitoring pressure gauge is within ±5% of the charging pressure, it indicates that the differential pressure loading system is airtight; if the pressure displayed by the monitoring pressure gauge exceeds ±5% of the charging pressure, open the exhaust valve to discharge Check the air volume of the air pressure differential loading system, and confirm each connection link of the differential pressure loading system one by one, and then repeat the above steps to re-check the air tightness of the differential pressure loading system until the air tightness of the differential pressure loading system meets the requirements; Step 5: Connect the differential pressure airbag module to the first fixed velcro of the mechanical fixing platform through the lower fixing velcro to complete the installation of the mechanical fixing platform and the differential pressure loading system. At this time, the high-pressure gas cylinder, exhaust port, and intake valve , The exhaust valve is in the closed state, the detection pressure gauge is at the initial zero position, and the differential pressure airbag module is in an uninflated state; Step 6: Paste the same number of second fixed velcros on the thin-walled structure at the corresponding positions where the upper fixed velcro is bonded, and bond the thin-walled structure to the upper fixed velcro through the second fixed velcro to realize the pressure difference. The installation of the loading system, and finally the thin-walled structure and the fixed pressure plate are screwed together; Step 7: Pressurize the thin-walled structure: first, open the exhaust port and the intake valve, the exhaust valve is in a closed state, check that the pressure gauge is at the initial zero position, open the high-pressure gas cylinder, and fill the differential pressure air bag module with the target pressure. Gas volume, and monitor the pressure value in real time by monitoring the pressure gauge. When the pressure value reaches the target pressure, close the high-pressure gas cylinder and keep the pressure for 5 minutes. When the monitoring pressure value displayed by the monitoring pressure gauge is in a stable state and within the range of ±5% of the target pressure When inside, start the vibration test; Step 8: Start the vibration test bench and conduct vibration test on the thin-walled structure according to the given vibration test conditions.

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