Simulation device and method for testing pressure bearing strength of special-shaped curved surface

Abstract

The invention belongs to the technical field of quality detection, and relates to a simulation device and method for testing the pressure bearing strength of a special-shaped curved surface. The device comprises a first fixing frame, a second fixing frame and a supporting column. The first fixing frame and the second fixing frame are oppositely arranged, the supporting column is obliquely arranged, and the upper end of the supporting column is fixedly connected to the first fixing frame; the special-shaped curved surface is fixedly mounted on the first fixing frame; a sensor for acquiring pressure and displacement is arranged on the special-shaped curved surface, and the sensor is connected with a data acquisition system; a frame box is installed on the second fixing frame, a composite air bag is installed in the frame box, and the extending end of the composite air bag faces the to-be-tested special-shaped curved surface and is used for applying pressure to the special-shaped curved surface; the composite air bag is connected with an air source used for inflating the composite air bag. The problem that in the prior art, calculation analysis depends on a theoretical model or a calculation formula, and consequently evaluation is inaccurate is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of quality inspection, and in particular relates to a simulation device and method for testing the pressure bearing strength of special-shaped curved surfaces. Background Art

[0002] In the aerospace field, pressure tests are performed on the curved structures of aircraft fuselages and wings to ensure that they can withstand loads such as air pressure during flight; in the automotive industry, pressure tests are performed on curved components such as car bodies and engine hoods to improve vehicle safety and durability; in the shipbuilding field, curved structures such as hull shells are tested to ensure that ships can withstand external forces such as water pressure in the water; in the construction industry, pressure tests are performed on curved building structures such as large-span roofs and domes to ensure structural stability and safety.

[0003] Currently, when a surface is irregularly shaped or subjected to pressure, the stress distribution within it is often more complex than that of a regular-shaped structure, making it difficult to accurately calculate and analyze using simple theoretical models or formulas. This complicates data processing and interpretation, potentially leading to inaccurate assessments of the compressive strength of irregularly shaped surfaces and causing stress concentrations on or within the material, resulting in significantly greater stress in some areas than in others.

[0004] Therefore, there is an urgent need for a curved surface compressive strength testing device and method that can truly simulate the stress conditions of the curved surface in actual use and has high reliability and accuracy to solve the problems existing in the existing technology. Summary of the Invention

[0005] The purpose of the present invention is to provide a simulation device and method for testing the compressive strength of special-shaped curved surfaces, which solves the problem that the existing technology relies on theoretical models or calculation formulas for calculation and analysis, resulting in inaccurate evaluation.

[0006] The present invention is achieved through the following technical solutions: A simulation device for testing the compressive strength of a special-shaped curved surface, comprising a first fixing frame, a second fixing frame and a support column; The first fixing frame and the second fixing frame are arranged opposite to each other, the support column is arranged obliquely, and the upper end of the support column is fixedly connected to the first fixing frame; The special-shaped curved surface is fixedly mounted on the first fixing frame; Sensors for obtaining pressure and displacement are provided on the special-shaped curved surface, and the sensors are connected to a data acquisition system; A frame box is installed on the second fixing frame, and a composite airbag is installed in the frame box. The extended end of the composite airbag faces the special-shaped curved surface to be tested, and is used to apply pressure to the special-shaped curved surface; The composite airbag is connected to an air source for inflating the composite airbag.

[0007] Furthermore, the gas source adopts an air compressor, and the air compressor is connected to a pressure control system.

[0008] Furthermore, the composite airbag includes an aluminum frame and a retractable portion of a soft airbag connected to the outside of the aluminum frame, an air nozzle is connected to one side of the aluminum frame, and the air nozzle is connected to an air source; The aluminum frame is embedded in the frame box and movably connected to the frame box; the retractable part of the soft airbag is bonded to the aluminum frame.

[0009] Furthermore, the air nozzle is connected to one end of the air pipe, and the other end of the air pipe is connected to the air source.

[0010] Furthermore, a frame hole is prefabricated on the frame box, and the air nozzle passes through the frame hole.

[0011] Furthermore, the first fixing frame, the second fixing frame and the support column are fixed to the ground by screws.

[0012] Furthermore, the special-shaped curved surface is made of the same material as the curved surface to be tested into a physical model with the same structure.

[0013] Furthermore, the special-shaped curved surface is fixed to the curved surface fixing frame by screws, and the curved surface fixing frame is further fixed to the first fixing frame by screws.

[0014] The present invention also discloses a simulation method for testing the compressive strength of a special-shaped curved surface, which is implemented based on the simulation device and specifically includes the following steps: S1. Before the composite airbag is inflated, the data acquisition system is used to record the initial data of each sensor, where the initial data is the initial value of the displacement; S2. Turn on the air source and inflate the composite airbag with compressed air, forcing the composite airbag surface to evenly contact and gradually apply pressure to the irregular curved surface. Maintain this pressure for several minutes, wait for the pressure to stabilize, and then record the pressure and displacement data. S3. Gradually increase the pressure according to the preset increments until the pressure gradually reaches the set pressure and maintain it for several minutes. Repeat this process. During the loading process, continuously observe whether the special-shaped curved surface has any abnormalities, and transmit the test data to the data acquisition system to record the pressure value and corresponding displacement data when the abnormality occurs. When the preset maximum pressure, i.e. the set pressure, is reached, the special-shaped curved surface structure is obviously damaged or the displacement reaches the allowable limit, the gas source is turned off and the pressure loading is stopped; S4. Based on the pressure and displacement data collected during the test, a pressure-displacement curve is drawn, and the compressive strength and elastic modulus of the special-shaped curved surface are calculated based on the pressure-displacement curve.

[0015] Furthermore, before S1, the air in the composite airbag is removed. The specific process is as follows: Open the air source and use the compressed air to pre-inflate the composite airbag. Check the stability of the device. When everything is normal, remove the air from the composite airbag.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention discloses a simulation device and method for testing the compressive strength of irregularly shaped curved surfaces. Utilizing the principle of airbag back-propagation, the device eliminates the need for direct contact with the object being measured, thus avoiding the surface damage and mismeasurements that can occur with contact-based measurements. By inflating the airbag and applying uniform pressure to the surface, the device can more realistically simulate the stress conditions experienced by the surface in actual use, resulting in more reliable and accurate test results. During the experiment, the composite airbag pressure and surface deformation can be monitored in real time, allowing for timely acquisition of experimental data. This facilitates a deeper understanding of the mechanical behavior of the surface under pressure, providing a reliable basis for subsequent design, analysis, and improvement.

[0017] The test has good repeatability, a relatively simple experimental process, and easy-to-control operation. Simply following the steps ensures repeatability, facilitating multiple measurements and comparative analysis, and ensuring more reliable data. The test is highly adaptable, enabling complex curved surfaces to meet strength and pressure resistance testing requirements by varying the shape and size of the composite airbag. Operation is simple and fast, and the test is highly environmentally adaptable. Utilizing environmentally adaptable design principles and adaptive materials, the airbag maintains stable performance in extreme temperatures and humidity environments, meeting testing requirements in diverse environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the structure of a simulation device for testing the compressive strength of a special-shaped curved surface according to the present invention; Figure 2 Schematic diagram of the structure of the composite airbag.

[0019] Among them: 1. Frame box; 2. Composite airbag; 3. Base; 4. First fixing frame; 5. Second fixing frame; 6. Curved surface fixing frame; 7. Special-shaped curved surface; 8. Measuring tool; 9. Support column; 10. Data acquisition system; 11. Frame hole; 12. Air compressor; 13. Air pipe; 14. Screws; 21. Aluminum frame; 22. Curved surface of soft airbag; 23. Retractable part of soft airbag; 24. Air nozzle. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clear, the following is a further detailed description with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. That is, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments.

[0021] The components described and illustrated in the drawings and embodiments of the present invention may be arranged and designed in a variety of different configurations. Therefore, the detailed description of the embodiments of the present invention provided in the following drawings is not intended to limit the scope of the claimed invention, but merely represents a selected embodiment of the present invention. All other embodiments derived by those skilled in the art based on the drawings and embodiments of the present invention without inventive effort shall fall within the scope of protection of the present invention.

[0022] It should be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, element, method, article, or device comprising a series of elements includes not only those elements but also other elements not explicitly listed, or also includes elements inherent to the process, element, method, article, or device. In addition, the term "tilted" is based on the orientation and positional relationship of the devices or components shown in the drawings and is intended only to better describe the present invention. It does not require that the devices, components, or devices shown must have this specific orientation, and therefore should not be understood as limiting the present invention.

[0023] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0024] like Figure 1 and Figure 2 As shown, the present invention designs a simulation device for testing the pressure bearing strength of special-shaped curved surfaces, including a first fixing frame 4, a second fixing frame 5, a frame box 1, a support column 9, a data acquisition system 10, an air compressor 12, and a composite airbag 2.

[0025] Specifically, the first fixing frame 4 , the second fixing frame 5 and the support column 9 are fixed to the ground by screws 14 .

[0026] The first fixing frame 4 and the second fixing frame 5 are arranged opposite to each other, the support column 9 is arranged at an angle, and the upper end of the support column 9 is fixedly connected to the first fixing frame 4, the special-shaped curved surface 7 is fixed to the curved surface fixing frame 6 by screws 14, and the curved surface fixing frame 6 is fixedly installed on the first fixing frame 4 by screws 14.

[0027] A frame box 1 is mounted on the second fixing frame 5 , and a composite airbag 2 is mounted in the frame box 1 . The extended end of the composite airbag 2 faces the irregular curved surface 7 to be tested, and is used to apply pressure to the irregular curved surface 7 .

[0028] Specifically, the frame box 1 is made of aluminum alloy. The frame box 1 is connected to a base 3 , which is fixed to the second fixing frame 5 by screws 14 .

[0029] like Figure 2As shown, the composite airbag 2 comprises an aluminum frame 21 and a flexible, soft airbag portion 23 attached to the outside of the aluminum frame 21. A gas nozzle 24 is connected to one side of the aluminum frame 21. The gas nozzle 24 is connected to one end of the air tube 13, and the other end of the air tube 13 is connected to the air compressor 12. The aluminum frame 21 is embedded in the frame box 1 and is movably connected to the frame box 1; the flexible, soft airbag portion 23 is bonded to the aluminum frame 21.

[0030] Specifically, a frame hole 11 is prefabricated on the frame box 1 , and the air nozzle 24 passes through the frame hole 11 .

[0031] During testing, a plurality of measuring tools 8 are arranged on the surface of the special-shaped curved surface 7 and are connected to the data acquisition system via a data transmission line.

[0032] Working principle: The special-shaped curved surface 7 is made of the same material as the curved surface to be tested, and a physical model with the same structure is made. An airbag that matches the shape of the curved surface is made according to the shape of the curved surface. It is fixed on the test bench and connected to the air compressor. Air is inflated into the composite airbag 2. The retractable part 23 of the soft airbag expands so that the soft airbag curved surface 22 fits on the special-shaped curved surface 7 and applies pressure. The strain and stress distribution of the surface under different pressures are recorded by measuring tools such as strain gauges and pressure sensors to evaluate whether its strength meets the requirements.

[0033] The test method of the simulation device for testing the compressive strength of special-shaped curved surfaces mentioned above specifically includes the following steps: 1. Preliminary experiment Open the valve of the air compressor 12 to allow compressed air to pass through the air pipe 13 to pre-inflate the composite airbag 2. Check the stability of the equipment. After the system is normal, remove the air in the composite airbag 2.

[0034] When pre-filling, apply a 10% setting.

[0035] 2. Formal Experiment a. Before the composite airbag 2 is inflated, the data acquisition system 10 is used to record the initial data of each sensor, where the initial data is the initial value of the displacement.

[0036] b. Open the valve of the air compressor 12 and allow compressed air to flow evenly and slowly into the composite airbag 2 through the air pipe 13, causing the retractable portion 23 of the composite airbag 2 to extend, forcing the curved surface 22 of the soft airbag to evenly contact and gradually apply pressure to the irregular curved surface 7. Maintain this pressure for 1 minute, wait for the pressure to stabilize, and then record the pressure and displacement data.

[0037] c. Gradually increase the pressure in increments of 20% of the set pressure until it reaches the set pressure and maintain it for 1 minute; repeat this process. During the loading process, continuously observe whether the special-shaped curved surface 7 has any abnormalities, and transmit the test data to the data acquisition system 10 through the data transmission line, and record in detail the pressure value and corresponding displacement data when the abnormality occurs.

[0038] When the preset maximum pressure, i.e., the set pressure, is reached and the structure of the special-shaped curved surface 7 is obviously damaged (such as cracked, severely deformed, etc.) or the displacement reaches the allowable limit value, the air compressor 12 is turned off and the pressure loading is stopped.

[0039] 3. Data collation and analysis a. Organize the pressure and displacement data collected during the test and draw a pressure-displacement curve. Based on the curve, analyze the deformation characteristics and pressure-bearing performance of the special-shaped curved surface 7 structure at different pressure stages, and calculate key parameters such as pressure-bearing strength and elastic modulus.

[0040] b. Based on relevant standards and design requirements, evaluate whether the structural strength of the special-shaped curved surface 7 meets the expected requirements, analyze and summarize the test results, and write a test analysis report to provide a strong basis for the improvement of the curved surface structure design or quality judgment.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A simulation device for testing the compressive strength of a special-shaped curved surface, characterized in that: It comprises a first fixing frame (4), a second fixing frame (5) and a support column (9); The first fixing frame (4) and the second fixing frame (5) are arranged opposite to each other, the support column (9) is arranged obliquely, and the upper end of the support column (9) is fixedly connected to the first fixing frame (4); The special-shaped curved surface (7) is fixedly mounted on the first fixing frame (4); A sensor for obtaining pressure and displacement is provided on the special-shaped curved surface (7), and the sensor is connected to a data acquisition system (10); A frame box (1) is mounted on the second fixing frame (5), a composite airbag (2) is mounted in the frame box (1), and an extended end of the composite airbag (2) faces the irregular curved surface (7) to be tested, for applying pressure to the irregular curved surface (7); The composite airbag (2) is connected to an air source for inflating the composite airbag (2).

2. A simulation device for testing the compressive strength of a special-shaped curved surface according to claim 1, characterized in that: The air source adopts an air compressor (12), and the air compressor (12) is connected to a pressure control system.

3. The simulation device for testing the compressive strength of a special-shaped curved surface according to claim 1, characterized in that: The composite airbag (2) includes an aluminum frame (21) and a flexible airbag portion (23) connected to the outside of the aluminum frame (21). An air nozzle (24) is connected to one side of the aluminum frame (21), and the air nozzle (24) is connected to an air source. The aluminum frame (21) is embedded in the frame box (1) and is movably connected to the frame box (1); the telescopic part (23) of the soft airbag is bonded to the aluminum frame (21).

4. The simulation device for testing the compressive strength of a special-shaped curved surface according to claim 3, characterized in that: The air nozzle (24) is connected to one end of the air pipe (13), and the other end of the air pipe (13) is connected to the air source.

5. The simulation device for testing the compressive strength of a special-shaped curved surface according to claim 3, characterized in that: A frame hole (11) is prefabricated on the frame box (1), and the air nozzle (24) passes through the frame hole (11).

6. The simulation device for testing the compressive strength of a special-shaped curved surface according to claim 1, characterized in that: The first fixing frame (4), the second fixing frame (5) and the support column (9) are fixed to the ground by screws (14).

7. The simulation device for testing the compressive strength of a special-shaped curved surface according to claim 1, characterized in that: The special-shaped curved surface (7) is made of the same material as the surface to be tested into a physical model with the same structure.

8. The simulation device for testing the compressive strength of a special-shaped curved surface according to claim 1, characterized in that: The special-shaped curved surface (7) is fixed to the curved surface fixing frame (6) by screws (14), and the curved surface fixing frame (6) is fixed to the first fixing frame (4) by screws (14).

9. A simulation method for testing the compressive strength of a special-shaped curved surface, characterized in that: The simulation device according to any one of claims 1 to 8 is implemented, specifically comprising the following process: S1. Before the composite airbag (2) is inflated, the data acquisition system (10) is used to record the initial data of each sensor, where the initial data is the initial value of the displacement; S2, open the air source and inflate the composite airbag (2) with compressed air, forcing the surface of the composite airbag (2) to evenly contact and gradually apply pressure to the irregular curved surface (7), and maintain this for several minutes. After the pressure stabilizes, record the pressure and displacement data; S3, gradually increasing the pressure according to the preset increments until the pressure gradually reaches the set pressure and maintaining it for several minutes; repeating this process, during the loading process, continuously observing whether the special-shaped curved surface (7) has any abnormality, and transmitting the test data to the data acquisition system (10), recording the pressure value and corresponding displacement data when the abnormality occurs; When the preset maximum pressure, i.e., the set pressure, is reached, and the structure of the special-shaped curved surface (7) is obviously damaged or the displacement reaches the allowable limit value, the gas source is turned off and the loading pressure is stopped; S4. Based on the pressure and displacement data collected during the test, a pressure-displacement curve is drawn, and the compressive strength and elastic modulus of the special-shaped curved surface (7) are calculated based on the pressure-displacement curve.

10. A simulation method for testing the compressive strength of a special-shaped curved surface according to claim 9, characterized in that: Before S1, the air in the composite airbag (2) is first removed. The specific process is as follows: Open the air source to pre-inflate the composite airbag (2) with compressed air, check the stability of the device, and when everything is normal, remove the air in the composite airbag (2).

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