Device for testing buckling performance of ball cap structural member

Abstract

The utility model provides a device for testing the buckling performance of a ball cap structural member, which can accurately simulate the external pressure working condition of a thin-wall ball cap structural member under a high-temperature condition through the arrangement of a pressure loading system, a temperature rise and constant temperature system, an initial defect measurement system, a mechanical response monitoring system and a temperature field monitoring system. Comprising a constant-pressure heating working condition, a constant-temperature pressurizing working condition and a working condition of simultaneously increasing the temperature and the pressure, the mechanical response of the thin-wall ball cap structural member is monitored in real time, the whole-process overall monitoring of strain and displacement is carried out, and the buckling stability of the thin-wall ball cap structural member can be fully known.

Description

Technical Field

[0001] The utility model relates to a device for testing the buckling performance of a spherical cap structural member. Background Art

[0002] Circular spherical caps are commonly used in various engineering structures, such as spacecraft, hypersonic missiles, ships, chemical storage tanks, etc. In particular, the spherical cap structures in aerospacecraft usually need to work under the coupling conditions of internal and external pressures and thermal loads. High-speed aircraft in the atmosphere serve at the intersection of structural mechanics and fluid mechanics. Under extreme flight conditions, serious (and transient) thermal gradients will be generated, affecting the strength and stiffness of the structure.

[0003] In addition, aerospace structures need to meet the conflicting requirements of lightweight and high load-bearing capacity at the same time. The thin-walled circular spherical cap structure is also widely used because of its high mass efficiency. Therefore, the buckling stability problem of the spherical cap structure in the service state is crucial.

[0004] However, there is little experimental research on the buckling performance of thin-walled circular spherical cap structures under the coupling action of high temperature and pressure at present. Moreover, the buckling performance of thin-walled circular spherical cap structures under the coupling action of high temperature and pressure is a rather complex problem, which is affected not only by the form, size, and material of the structure, but also by factors such as initial deformation, geometric defects, and residual stress. Summary of the Utility Model

[0005] In view of this, the purpose of the utility model is to provide a device for testing the buckling performance of a spherical cap structural member to solve the above problems.

[0006] The utility model adopts the following scheme:

[0007] The present application provides a device for testing the buckling performance of a spherical cap structural member, including a high-temperature and high-pressure chamber with one side open and heat insulation cotton provided on the inner peripheral wall and the inner bottom wall, a spherical cap support for sealingly connecting the spherical cap structural member to the opening, and a computer electrically connected to:

[0008] A pressure loading system for forming a high-pressure environment in the high-temperature and high-pressure chamber; it includes a vacuum pump and a pressure sensor. The pressure pipe of the vacuum pump communicates with the inside of the high-temperature and high-pressure chamber for evacuating the high-temperature and high-pressure chamber; the pressure sensor is arranged inside the high-temperature and high-pressure chamber;

[0009] A temperature rising and constant temperature system, including a heating component arranged inside the high-temperature and high-pressure chamber for forming a high-temperature environment in the high-temperature and high-pressure chamber; and a temperature sensor arranged inside the high-temperature and high-pressure chamber;

[0010] Initial defect measurement system, including a three-dimensional scanning device and an ultrasonic detection device arranged above the spherical cap structural member; used to identify the geometry and structural defects of the spherical cap structural member;

[0011] Mechanical response monitoring system, including a 3D-DIC camera and a high-speed camera arranged above the spherical cap structural member; used to monitor and capture the global response of the spherical cap structural member in real time, and can transmit streaming media video through Ethernet, and then can view real-time images on a computer;

[0012] Temperature field monitoring system, including an infrared camera arranged above the spherical cap structural member; used to monitor the global temperature of the spherical cap structural member in real time and transmit temperature data to temperature control software in real time;

[0013] Through each system to simulate various working conditions of the spherical cap structural member in actual applications, and can conduct overall monitoring of the mechanical response of the spherical cap structural member in real time throughout the whole process.

[0014] Furthermore, the pressure loading system further includes a temperature control water tank for cooling the pressure pipeline.

[0015] Furthermore, the heating component is a silicon carbide rod heating component, and the temperature sensor is a thermocouple for temperature measurement.

[0016] Furthermore, the silicon carbide rod heating component includes a ceramic base and a plurality of silicon carbide rods vertically arranged and connected to the upper edge of the ceramic base.

[0017] Furthermore, a flange interface is arranged on the bottom wall of the high-temperature and high-pressure chamber for leading out the pressure pipe and the power supply line. After the interface is tightly docked, it is sealed with fireproof sealant.

[0018] Furthermore, the high-temperature and high-pressure chamber is filled with inert gas.

[0019] Furthermore, a heat-resistant heat-insulating glass is arranged between the mechanical response monitoring system, the temperature field monitoring system and the spherical cap structural member.

[0020] By adopting the above technical solutions, the following technical effects can be achieved by the present utility model:

[0021] The utility model provides a device for testing the buckling performance of a spherical cap structural member. By setting up a pressure loading system, a temperature rising and constant temperature system, an initial defect measurement system, a mechanical response monitoring system, and a temperature field monitoring system, it can accurately simulate the external pressure conditions of a thin-walled spherical cap structural member under high-temperature conditions, including constant pressure and temperature rising conditions, constant temperature and pressure loading conditions, and conditions where temperature and pressure increase simultaneously, and monitor the mechanical response of the thin-walled spherical cap structural member in real time, including the overall monitoring of the whole process of strain and displacement, so as to fully understand the buckling stability of the thin-walled spherical cap structural member. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present utility model, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 is a partial structural schematic diagram of a device for testing the buckling performance of a spherical cap structural member according to an embodiment of the present utility model;

[0024] Figure 2 is Figure 1 the sectional structural schematic diagram of;

[0025] Figure 3 is a structural schematic diagram of a device for testing the buckling performance of a spherical cap structural member according to an embodiment of the present utility model;

[0026] Reference numerals: high-temperature and high-pressure chamber 1, spherical cap support 2, spherical cap structural member 3, concrete bearing platform 4, high-temperature and high-pressure chamber bottom plate 5, high-temperature and high-pressure chamber wall 6, pressure pipe 7, ceramic base 8, silicon carbide rod 9, heat insulation cotton 10, 3D-DIC camera 11, high-speed camera 12, infrared camera 13, heat insulation glass 14, refractory sealant 15. Detailed Embodiments

[0027] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model. Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the claimed present utility model, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0028] Embodiment

[0029] Combined with Figures 1 to 3 As shown, this embodiment provides a device for testing the buckling performance of a spherical cap structural member 3, including a high-temperature and high-pressure chamber 1 with an opening on one side, a spherical cap support 2 for sealingly connecting the spherical cap structural member 3 to the opening, and the following components electrically connected to a computer:

[0030] A pressure loading system for creating a high-pressure environment inside the high-temperature and high-pressure chamber 1;

[0031] A temperature rising and constant temperature system for creating a high-temperature environment inside the high-temperature and high-pressure chamber 1;

[0032] An initial defect measurement system for identifying the geometric and structural defects of the spherical cap structural member 3;

[0033] A mechanical response monitoring system for real-time monitoring and capturing the global response of the spherical cap structural member 3, and capable of transmitting streaming media video through Ethernet and then enabling real-time image viewing on a computer;

[0034] A temperature field monitoring system for real-time monitoring of the global temperature of the spherical cap structural member 3 and real-time transmission of temperature data to temperature control software.

[0035] Through the settings of the pressure loading system, temperature rising and constant temperature system, initial defect measurement system, mechanical response monitoring system, and temperature field monitoring system, it is possible to accurately simulate the external pressure conditions of the thin-walled spherical cap structural member 3 under high-temperature conditions, including constant pressure and temperature rising conditions, constant temperature and pressure increasing conditions, and conditions where both temperature and pressure increase simultaneously, and to conduct real-time monitoring of the mechanical response of the thin-walled spherical cap structural member 3, including the overall monitoring of the entire process of strain and displacement, so as to fully understand the buckling stability of the thin-walled spherical cap structural member 3.

[0036] Specifically, in this embodiment, it includes a high-temperature and high-pressure chamber 1 with an opening on one side, a ball cap support 2 for sealingly connecting a ball cap structural member 3 to the opening, and a concrete foundation 4 for carrying the high-temperature and high-pressure chamber 1. When the ball cap structural member 3 is installed on the opening through the ball cap support 2, a refractory sealant 15 is used to seal the inside and outside of the joint. The high-temperature and high-pressure chamber 1 includes a high-temperature and high-pressure chamber bottom plate 5 and a ring-shaped high-temperature and high-pressure chamber wall 1 arranged on the high-temperature and high-pressure chamber bottom plate 5.

[0037] The pressure loading system includes a vacuum pump (not shown in the drawing) for evacuating the high-temperature and high-pressure chamber 1, which is connected to the inside of the high-temperature and high-pressure chamber 1 through a pressure pipe 7, and a pressure sensor arranged inside the high-temperature and high-pressure chamber 1. The vacuum pump is used to create a negative pressure inside the high-temperature and high-pressure chamber 1, and cooperate with the control of a computer through the pressure sensor to maintain or uniformly change the internal pressure of the high-temperature and high-pressure chamber 1.

[0038] The heating and constant temperature system includes a silicon carbide rod 9 heating assembly and a temperature-measuring thermocouple. The temperature of the silicon carbide rod 9 heating assembly is controlled through temperature control software in a computer, and the temperature measured by the temperature-measuring thermocouple is displayed to simulate the high-temperature conditions under various working conditions inside the high-temperature and high-pressure chamber 1. The silicon carbide rod 9 heating assembly includes a ceramic base 8 and a plurality of silicon carbide rods 9 connected to the ceramic base 8. And heat insulation cotton 10 is arranged on the inner peripheral wall and the inner bottom wall of the high-temperature and high-pressure chamber 1 to weaken or even isolate the damage of the high-temperature environment to the chamber of the high-temperature and high-pressure chamber 1; at the same time, an inert gas is filled inside the high-temperature and high-pressure chamber 1 to ensure the safety of the heating components. By using the silicon carbide rod 9 heating group, uniform heating of the ball cap structure is realized. Multiple groups of high-power silicon carbide rods 9 can rapidly heat the chamber and can achieve a constant temperature working condition under the condition of unilateral heat dissipation of the ball cap. And the silicon carbide rod 9 has stable working performance, can withstand high-pressure and low-pressure environments, and can work stably in a chamber filled with inert gas.

[0039] The initial defect measurement system includes a three-dimensional scanning device (not shown in the drawing) for identifying the geometric initial defects of the ball cap structural member 3, and an ultrasonic detection device (not shown in the drawing) for detecting the internal defects of the ball cap structural member 3. The three-dimensional scanning device is responsible for accurately constructing a three-dimensional model of the ball cap, and through a detailed comparison with the three-dimensional model of an ideal specimen, the geometric initial defects of the specimen are accurately identified. And the ultrasonic detection device uses advanced Lamb wave technology to comprehensively detect the internal defects of the specimen to accurately identify various potential problems such as cracks, pores, interlayers, scratches, and holes.

[0040] The mechanical response monitoring system includes a 3D-DIC camera 11 and a high-speed camera 12 arranged above the spherical cap structural member 3, which can capture the global response of the spherical cap specimen in real time, transmit the streaming media video through Ethernet, and then view the real-time images on a computer. The temperature field monitoring system includes an infrared camera 13, which can monitor the global temperature of the spherical cap specimen in real time through temperature monitoring software. The temperature data of the monitoring software is transmitted to the temperature control software of the heating and constant temperature system in real time as a reference for the heating power. And a heat-resistant heat-insulating glass 14 is arranged between the mechanical response monitoring system, the temperature field monitoring system and the spherical cap structural member 3 to avoid damage to the monitoring system caused by high-temperature heat flow.

[0041] The bottom plate 5 of the high-temperature and high-pressure chamber is made of 310S stainless steel, and flange interfaces are arranged on the bottom plate 5 of the high-temperature and high-pressure chamber for respectively leading out the pressure pipe 7 and the power supply line of the heating system. After the interfaces are tightly docked, fireproof sealant is also used for plugging.

[0042] Integrating the digital image correlation technology into the spherical cap high-temperature and high-pressure stability test device above can realize non-contact dynamic monitoring of the spherical cap structural member 3 under high temperature and high pressure, and can display the three-dimensional displacement and full-field strain of the spherical cap structural member 3 during the high-temperature and high-pressure process in real time.

[0043] Using the high-speed camera to collect full-size photography of the whole process of buckling of the spherical cap structure at a high frequency, and processing the captured images in the later stage, the morphology of the spherical cap structure at the initial buckling, post-buckling and buckling failure moments during the whole buckling process can be obtained.

[0044] Taking a certain aluminum alloy spherical cap structural member 3 with a curve radius R = 590mm, a projection plane radius of 500mm and a thickness of 0.5mm as an example, the steps of the test method using this test device are specifically described below. Among them, the spherical cap structural member 3 bears both high temperature and high external pressure loads during service. The service condition is that first an external pressure load of 0.5 Mpa appears, then the external pressure load remains unchanged, and then the heat load continuously increases. The heat load is a variable load, and the heating rate is 0.5 °C / s. The limit temperature when the spherical cap buckles is measured using this test device.

[0045] Step S1: Build each system and complete the initial debugging and calibration;

[0046] Step S2: Seal and connect the spherical cap structural member 3 to the opening of the high-temperature and high-pressure chamber 1 through the spherical cap support 2, and use fireproof sealant 15 to seal the inside and outside of the joint to form a closed space inside the high-temperature and high-pressure chamber 1;

[0047] Step S3: Identify the geometric and structural defects of the spherical cap structural member 3 through the initial defect measurement system, and retain the identified defects;

[0048] Specifically, a point cloud model of the spherical cap is formed using a three-dimensional scanning device and compared with the model of the perfect aluminum alloy spherical cap structural member 3 with a curve radius R = 590 mm and a projection plane radius of 500 mm, so as to obtain the full-field initial defects and the position of the maximum defect of the spherical cap structural member 3; then, an ultrasonic detection device is used to detect whether there are cracks, pores, interlayers, scratches, holes, etc. inside the aluminum alloy spherical cap structural member 3 through Lamb waves, and the geometric initial defects and internal defects are saved for subsequent research.

[0049] Step S3: Apply an external pressure load with a certain pressure loading rate to the spherical cap structural member 3 through a pressure loading system until the set pressure is reached; and capture the global response of the spherical cap structural member 3 in real time through a mechanical response monitoring system.

[0050] Specifically, set the vacuum pump to load at a pressure loading rate of 0.05 MPa / min until the set external pressure load is reached, and set the power of the vacuum pump to keep the pressure at 0.5 MPa; at the same time, the 3D-DIC camera 11 and the high-speed camera are used to capture the global response of the spherical cap structural member 3 in real time.

[0051] Step S4: After applying the external pressure load to the spherical cap structural member 3 and keeping it at the set value, apply a continuous thermal load with a heating rate of 0.5 °C / s to the spherical cap structural member 3 with the external pressure load maintained through a heating and constant temperature system, and monitor the global temperature of the spherical cap structural member 3 in real time through an infrared camera 13.

[0052] Step S5: When the spherical cap structural member 3 buckles and rapidly deforms and loses its load-bearing capacity, stop heating and unload the external pressure load.

[0053] The above is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention.

[0054] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings, and 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, and therefore should not be construed as a limitation to the present invention.

[0055] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality of" means two or more unless otherwise specifically defined.

[0056] In the present utility model, unless otherwise clearly specified and defined, terms such as "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0057] In the present utility model, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.

Claims

1. A device for testing the buckling performance of a ball cap structural member, characterized in that A high-temperature and high-pressure chamber with an opening on one side and heat-insulating cotton provided on its inner peripheral wall and inner bottom wall, a ball cap support for sealing and connecting a ball cap structural member to the opening, and components electrically connected to a computer: A pressure loading system for creating a high-pressure environment inside the high-temperature and high-pressure chamber; it includes a vacuum pump and a pressure sensor. The pressure pipe of the vacuum pump communicates with the inside of the high-temperature and high-pressure chamber for evacuating the high-temperature and high-pressure chamber; the pressure sensor is disposed inside the high-temperature and high-pressure chamber; A heating and constant-temperature system, including a heating component disposed inside the high-temperature and high-pressure chamber for creating a high-temperature environment inside the high-temperature and high-pressure chamber; and a temperature sensor disposed inside the high-temperature and high-pressure chamber; An initial defect measurement system, including a three-dimensional scanning device and an ultrasonic detection device disposed above the ball cap structural member; for identifying geometric and structural defects of the ball cap structural member; A mechanical response monitoring system, including a 3D-DIC camera and a high-speed camera disposed above the ball cap structural member; for real-time monitoring and capturing the global response of the ball cap structural member, and capable of transmitting streaming media video through Ethernet and then enabling real-time image viewing on a computer; A temperature field monitoring system, including an infrared camera disposed above the ball cap structural member; for real-time monitoring of the global temperature of the ball cap structural member and transmitting temperature data to temperature control software in real time; By means of each system, various working conditions of the ball cap structural member in actual applications are simulated, and the overall mechanical response of the ball cap structural member can be monitored in real time throughout the whole process.

2. The device for testing the buckling performance of the ball cap structural member according to claim 1, characterized in that, The pressure loading system further includes a temperature control water tank for cooling the pressure pipeline.

3. The device for testing the buckling performance of the ball cap structural member according to claim 1, characterized in that, The heating component is a silicon carbide rod heating component, and the temperature sensor is a thermocouple for temperature measurement.

4. The device for testing the buckling performance of the ball cap structural member according to claim 3, wherein, The silicon carbide rod heating component includes a ceramic base, and a plurality of silicon carbide rods vertically connected to the upper edge of the ceramic base.

5. The device for testing the buckling performance of the ball cap structural member according to claim 3, wherein A flange interface is provided on the bottom wall of the high-temperature and high-pressure chamber for leading out the pressure pipe and the power supply line. After the interface is tightly docked, it is sealed with fireproof sealant.

6. The device for testing the buckling performance of the ball cap structural member according to claim 3, characterized in that, The high-temperature and high-pressure chamber is filled with inert gas.

7. The device for testing the buckling performance of the ball cap structural member according to claim 1, characterized in that, A high-temperature resistant heat-insulating glass is provided between the mechanical response monitoring system, the temperature field monitoring system and the ball cap structural member.

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