Airship assembly testing method

Abstract

The invention discloses an airship assembly testing method, and relates to the technical field of airship testing. The airship assembly test method comprises the steps of obtaining design parameters of an airship, and determining a pressure change range in the airship and a preset pressure in the pressure change range based on the design parameters; based on the pressure change range, determining a relation spectrum of the mechanical force borne by the airship assembly, the preset temperature and the preset pressure; and based on the relation spectrum, controlling a test system to apply the mechanical force and the preset temperature to the airship assembly, and obtaining a test result. By applying the airship assembly test method disclosed by the invention, the airship assembly can be tested from two aspects of machinery and temperature, so that test support is provided for optimization design of the airship assembly.

Description

Technical Field

[0001] The present application relates to but is not limited to the field of airship testing technology, and in particular to an airship component testing method. Background Art

[0002] Near-space airships have the advantages of being able to fly at a fixed point, staying in the air for a long time, and having a wide detection range. At present, my country has set the research and development of stratospheric airships as a national strategic need. The airship flange assembly is the installation interface on the airship for important equipment such as fans, valves and pods. Its long-term service performance has an important impact on the overall structural stability of the airship and the air tightness of the capsule. The airship flange assembly must withstand not only the periodic changes in skin tension, but also the out-of-plane loads generated by equipment such as pods, propulsion brackets and ballast, as well as day and night temperature changes. The service conditions are very harsh. As the service time increases, if tiny gaps are generated around the airship flange assembly, the air tightness of the capsule will be reduced, shortening the flight time of the airship.

[0003] At present, there is no test method for testing the mechanical properties of airship flange assemblies. Most biaxial tensile test systems can only test the bearing capacity of airship skin materials. Existing studies have shown that airship flange assemblies are rigid-flexible coupling structures with complex nonlinear mechanical behavior characteristics, and their mechanical properties under different service conditions vary significantly. Therefore, research on mechanical property test methods for airship flange assemblies can fill the gap in this field. Summary of the invention

[0004] The airship component testing method provided in the present application can test the airship component from two aspects, mechanical and temperature, so as to provide experimental support for the optimized design of the airship component.

[0005] The present application provides an airship component testing method, which includes obtaining design parameters of the airship, determining a pressure variation range inside the airship and a preset pressure within the pressure variation range based on the design parameters; determining a relationship spectrum between a mechanical force, a preset temperature and a preset pressure borne by the airship component based on the pressure variation range; and controlling a test system to apply a mechanical force and a preset temperature to the airship component based on the relationship spectrum, and obtaining a test result.

[0006] The airship component testing method provided by the present application can determine the pressure variation range inside the airship based on the design parameters by obtaining the design parameters of the airship, and select a preset pressure within the pressure variation range, that is, simulate the internal pressure of the airship at a certain moment when it is working, so that the pressure variable can be more consistent with the actual situation of the airship when it is working. According to the preset pressure, the stress magnitude of the airship skin at this time can be inferred. When testing the airship component, the stress magnitude corresponds to the mechanical force that should be applied to the airship component under the preset pressure, thereby simulating the stress of the airship skin when the airship is working under the preset pressure. At the same time, according to the preset pressure, the corresponding ambient temperature of the airship under the preset pressure can be calculated. In this way, when testing, the preset temperature applied to the airship component can be adjusted by the ambient temperature. Thus, the relationship spectrum between the mechanical force, the preset temperature and the preset pressure can be obtained. In this way, the relationship spectrum among mechanical force, preset temperature and preset pressure can be calculated by presetting and adjusting the preset pressure. When conducting a test, the mechanical force and preset temperature that should be applied to the airship components when the internal preset pressure of the airship changes can be determined based on the relationship spectrum, thereby simulating the state of the airship in flight and testing the airship components from both mechanical and temperature aspects, so that the test results of the airship components are more in line with engineering reality, so as to provide experimental support for the optimal design of the airship components.

[0007] In a possible implementation of the present application, in the step of determining the relationship spectrum of the mechanical force, preset temperature and preset pressure borne by the airship component based on the pressure variation range, the testing method includes: adjusting the preset pressure based on the pressure variation range; determining the mechanical load spectrum of the mechanical force varying with the preset pressure and the temperature load spectrum of the preset pressure varying with the preset temperature based on the adjusted preset pressure; determining the relationship spectrum based on the mechanical load spectrum and the temperature load spectrum.

[0008] In a possible implementation of the present application, in the step of determining a mechanical load spectrum of mechanical force changing with a preset pressure and a temperature load spectrum of a preset pressure changing with a preset temperature based on an adjusted preset pressure, the testing method includes: determining a first relationship between the mechanical force and the preset pressure based on design parameters; and calculating the mechanical force corresponding to each preset pressure based on the first relationship to determine a mechanical load spectrum of mechanical force changing with the preset pressure.

[0009] In a possible implementation of the present application, in the step of determining a first relationship between mechanical force and preset pressure based on design parameters, the testing method includes: performing a force analysis on the airship component based on the design parameters to determine the annular curvature and longitudinal curvature of the installation point where the airship component is installed on the airship; determining the relationship between the longitudinal stress, annular stress and preset pressure to which the airship component is subjected based on the annular curvature and longitudinal curvature; obtaining the test parameters of the airship component, and determining the first relationship based on the relationship between the longitudinal stress, annular stress and preset pressure to which the airship component is subjected.

[0010] In a possible implementation of the present application, the first relational expression is:

[0011]

[0012] Among them, σ x is the longitudinal stress on the airship components; σ y is the hoop stress on the airship components; T x The longitudinal mechanical force applied by the test system to the airship components; T y To test the lateral mechanical forces applied by the system to the airship components; x is the test parameter of the airship component in the longitudinal direction; l y is the test parameter of the airship assembly in the horizontal direction; t is one of the test parameters of the airship assembly; P is the preset pressure.

[0013] In a possible implementation of the present application, in the step of determining a mechanical load spectrum in which the mechanical force changes with the preset pressure and a temperature load spectrum in which the preset pressure changes with the preset temperature based on the adjusted preset pressure, the testing method also includes: determining a second relationship between the preset temperature and the preset pressure based on the design parameters; and calculating the preset temperature corresponding to each preset pressure after adjustment based on the second relationship to determine the temperature load spectrum in which the preset pressure changes with the preset temperature.

[0014] In a possible implementation of the present application, in the step of determining a second relationship between a preset temperature and a preset pressure based on design parameters, the testing method includes: obtaining a volume change of the airship under a preset pressure based on the design parameters; obtaining a relationship between a preset gas average temperature and a preset gas volume, determining a relationship between a preset pressure and a preset gas average temperature based on the volume change of the airship under the preset pressure, and determining a second relationship.

[0015] In a possible implementation of the present application, the second relational expression is:

[0016]

[0017] Among them, P airis the atmospheric pressure outside the airship; V0 is the initial volume of the airship; K is the proportional constant between the volume and the internal pressure of the airship; m he is the preset gas mass; μ is the molar mass of the preset gas; R is the molar gas constant; P is the preset pressure, T he is the average temperature of the preset gas.

[0018] In a possible implementation of the present application, in the step of adjusting the preset pressure based on the pressure variation range, the testing method includes: determining the number of test repetitions based on the pressure variation range; determining, according to the number of repetitions, a preset difference by which the preset pressure needs to be adjusted each time the test is repeated; and calculating the preset pressure for repeated testing based on the preset difference.

[0019] In a possible implementation of the present application, in the step of determining a mechanical load spectrum of mechanical force that changes with a preset pressure, and a temperature load spectrum of a preset pressure that changes with a preset temperature based on an adjusted preset pressure, the testing method includes: determining whether the preset pressure is within a pressure variation range; if the preset pressure is within the pressure variation range, adjusting the preset pressure according to a preset difference, and determining a mechanical load spectrum of mechanical force that changes with a preset pressure, and a temperature load spectrum of a preset pressure that changes with a preset temperature; if the preset pressure is outside the pressure variation range, ending the test.

[0020] In a possible implementation of the present application, in the step of controlling the test system to apply mechanical force and preset temperature to the airship component based on the relationship spectrum and obtaining the test results, the test method includes: building a test system and inputting the relationship spectrum; conducting a preliminary experiment based on the relationship spectrum; applying a mechanical force and a preset temperature corresponding to an initial preset pressure to the airship component based on the relationship spectrum; adjusting the preset pressure based on the pressure change range, and repeatedly applying the mechanical force and preset temperature corresponding to the current preset pressure to the airship component.

[0021] In a possible implementation of the present application, in the step of controlling the test system to apply mechanical force and preset temperature to the airship component based on the relationship spectrum and obtaining the test results, the test method also includes: judging the relationship between the skin deformation of the airship component and the limit value of the skin deformation; when the skin deformation is less than the limit value of the skin deformation, adjusting the preset pressure and continuing the test; when the skin deformation is greater than the limit value of the skin deformation, ending the test.

[0022] In a possible implementation of the present application, in a pre-experimental step based on a relationship spectrum, the testing method includes: based on the relationship spectrum, gradually increasing the mechanical force applied to the airship component to a maximum value; based on the relationship spectrum, gradually reducing the preset temperature applied to the airship component to a minimum value; and acquiring test data of the airship component in the pre-experiment in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 One of the step diagrams of the airship component testing method provided in the embodiment of the present application;

[0024] Figure 2 A schematic diagram of the flange and skin structure of the airship component test system provided in an embodiment of the present application;

[0025] Figure 3 A schematic diagram of the structure of an airship component testing system provided in an embodiment of the present application;

[0026] Figure 4 A schematic diagram of the internal structure of a temperature control box of an airship component test system provided in an embodiment of the present application;

[0027] Figure 5 A schematic diagram of the geometric shape of a preset airship in the airship component testing method provided in an embodiment of the present application;

[0028] Figure 6 One of the step diagrams of the airship component testing method provided in the embodiment of the present application;

[0029] Figure 7 One of the step diagrams of the airship component testing method provided in the embodiment of the present application;

[0030] Figure 8 One of the step diagrams of the airship component testing method provided in the embodiment of the present application;

[0031] Fig. 9 A schematic diagram of the structure of an airship component testing system provided in an embodiment of the present application;

[0032] Fig.10 A schematic diagram of a force analysis of an airship component on a preset airship in the airship component testing method provided in an embodiment of the present application;

[0033] Fig.11 A schematic diagram of force analysis of an airship component in the airship component testing method provided in an embodiment of the present application;

[0034] Fig.12 A mechanical load spectrum in the airship component testing method provided in an embodiment of the present application;

[0035] Fig.13 One of the step diagrams of the airship component testing method provided in the embodiment of the present application;

[0036] Fig.14 One of the step diagrams of the airship component testing method provided in the embodiment of the present application;

[0037] Fig.15 A schematic diagram of heat analysis of an airship during its airborne flight in the airship component testing method provided in an embodiment of the present application;

[0038] Fig.16 The temperature load spectrum in the airship component testing method provided in the embodiment of the present application;

[0039] Fig.17 A relationship spectrum in the airship component testing method provided in an embodiment of the present application;

[0040] Fig.18 One of the step diagrams of the airship component testing method provided in the embodiment of the present application;

[0041] Fig.19 One of the step diagrams of the airship component testing method provided in the embodiment of the present application;

[0042] Fig. 20 One of the step diagrams of the airship component testing method provided in the embodiment of the present application;

[0043] Fig.21 One of the step diagrams of the airship component testing method provided in the embodiment of the present application;

[0044] Fig. 22 One of the step diagrams of the airship component testing method provided in the embodiment of the present application;

[0045] Fig.23 This is one of the step diagrams of the airship component testing method provided in the embodiment of the present application.

[0046] Reference numerals:

[0047] 1-skin; 2-flange; 3-temperature control box; 31-chamber; 32-temperature control assembly; 4-loading mechanism; 41-first loading assembly; 42-connection assembly; 43-second loading assembly; 44-bracket; 5-three-dimensional full-field strain measurement system installation and integration; 6-central control system; X-first loading direction; Y-second loading direction; Z-third loading direction. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the specific technical solution of the present application will be further described in detail below in conjunction with the drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application.

[0049] In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more.

[0050] In addition, in the embodiments of the present application, directional terms such as "up", "down", "left" and "right" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they may change accordingly according to the changes in the orientation of the components in the drawings.

[0051] In the embodiments of the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0052] In the embodiments of the present application, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0053] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0054] The embodiment of the present application provides an airship component testing method, which can test the airship component from two aspects, mechanical and temperature, to provide experimental support for the optimized design of the airship component.

[0055] Reference Figure 1 The present application embodiment provides an airship component testing method including:

[0056] S100: acquiring design parameters of the airship, and determining a pressure variation range inside the airship and a preset pressure within the pressure variation range based on the design parameters;

[0057] S200 determines the relationship spectrum between the mechanical force, the preset temperature and the preset pressure borne by the airship component based on the pressure variation range;

[0058] Based on the relationship spectrum, S300 controls the test system to apply mechanical force and preset temperature to the airship components and obtain test results.

[0059] It should be added that, refer to Figure 2 The test system is used to test the airship component. In one embodiment of the present application, the airship component includes a connected skin 1 and a flange 2. The flange 2 is installed in the center of the skin 1. The flange 2 is divided into an inner part and an outer part. The inner part and the outer part clamp the skin 1 in the middle and are installed on the skin 1 by screws, so as to form an airship component for testing.

[0060] Reference Figure 3 and Figure 4 In an embodiment of the present application, the test system may include: a temperature control box 3 and a loading mechanism 4, the temperature control box 3 includes a chamber 31 and a temperature control component 32; the space in the chamber 31 can at least accommodate the airship flange 2 component and the temperature control component 32; the temperature control component 32 is used to adjust the temperature in the chamber 31 to apply different preset temperatures to the airship component for testing.

[0061] Reference Figure 3 and Fig. 9 In the embodiment of the present application, the loading mechanism 4 may include a first loading component 41 and a connecting component 42, wherein the first loading component 41 is used to provide a driving force for driving the connecting component 42 to move relative to the temperature control box 3. The connecting mechanism is connected to the skin 1, and the movement of the connecting mechanism relative to the temperature control box 3 can apply a mechanical force to the skin 1, driving the skin 1 to tighten or relax, simulating the tension of the skin 1 when the pressure inside the airship changes.

[0062] In the embodiment of the present application, the design parameters of the airship include but are not limited to the mechanical properties of the airship skin 1 material, the size of the airship, the initial volume of the airship, the parameters of the buoyancy gas, the flight conditions of the airship, etc.

[0063] In the embodiment of the present application, the lower limit of the internal pressure of the airship is the minimum value for maintaining the shape of the airship for effective attitude control, and the upper limit of the internal pressure of the airship is the maximum value that the airship can withstand for normal operation, that is, the mechanical properties of the skin 1 material determine the upper limit of the airbag pressure.

[0064] Based on step S100, for example, a preset airship is selected, referring to Figure 5 The cross section of the airship along the axis of symmetry is generally a smooth curve, which is determined in the overall design stage. The radius of curvature increases from the bow to the stern, thereby reducing the possibility of airflow separation. The airship contour equation can be expressed as:

[0065] y=f(x) (1)

[0066] Obtain the design parameters of the preset airship, refer to Table 1, which shows some of the design parameters obtained by the preset airship:

[0067] Table 1

[0068] Design parameters Numeric <![CDATA[Major axis (a1)]]> 83.3 meters (m) <![CDATA[Major axis (a2)]]> 166.7 meters (m) Short axis (b) 37.5 meters (m) area 48054 square meters (m2) volume 73600 cubic meters (m3) Buoyancy gas Helium Helium mass 8830 kilograms (kg) Total mass of airship 64270 kilograms (kg) Flight altitude 20 kilometers (km) Skin elastic modulus <![CDATA[10GPa(1GPa=1×10 10 Pascal)]]> Skin tensile strength 2.7GPa Skin safety factor 10 Maximum skin strain 2.7％ Skin thickness 0.3mm Calculation time June 21 Flight latitude 30°N

[0069] In order to maintain the aerodynamic shape of the airship, the lower limit of the internal pressure of the airship shall not be less than 3% of the external atmospheric pressure, which can be expressed as formula 2:

[0070] P Min ≥0.03×P a (2)

[0071] Among them, P Min is the lower limit of the internal pressure of the airship, P a is the outside atmospheric pressure.

[0072] According to Table 1, the preset working altitude of the airship is 20 kilometers (km). According to the standard atmospheric parameter table, the atmospheric pressure at an altitude of 20 kilometers (km) is about 5 kilopascals (kPa), that is, P a is 5 kPa. By using formula 2, we can get that at this time, the lower limit of the internal pressure of the airship (P Min ) is greater than or equal to 150 Pa.

[0073] Reference Figure 5 , Figure 5 This is a schematic diagram of the geometric shape of the preset airship. The airship shape is a main airbag formed by rotating a smooth curve formed by connecting two semi-ellipsoid lines. The two ellipsoids share a short axis b, and the major semi-axes of the two ellipsoids are a1 and a2 respectively.

[0074] The contour equations of the two semi-ellipsoid lines can be expressed as:

[0075]

[0076] The maximum principal stress of the airship capsule is mainly concentrated in the middle position. As the radius of gyration of the capsule decreases, the principal stress of the capsule decreases toward the head and tail of the airship. The minimum principal stress of the capsule is mainly concentrated in the head and tail of the airship. Therefore, the strength margin and safety of the capsule can be judged according to the stress at the maximum curvature of the airship.

[0077] Reference Figure 5 , for example, the maximum turning radius of the preset airship is the junction of two ellipsoid lines, and the coordinates of the maximum turning radius are (0, b). In the embodiment provided in the present application, according to Formula 4, the relationship between the maximum stress of the airship hull and the internal pressure of the airship is expressed, and Formula 5 is the relationship between the tensile strength of the skin, the safety factor of the skin and the stress of the airship hull.

[0078]

[0079]

[0080] where [σ x] is the required longitudinal stress of the airship skin, [σ y ] is the required hoop stress of the airship skin, σ b Indicates the tensile strength of the skin, n indicates the safety factor. According to Table 1, the preset tensile strength of the airship skin is 2.7 GPa. Considering the complex structure of the airship, the safety factor is 10. Substituting into Formula 4 and Formula 5, it can be calculated that the airship pressure must be less than or equal to 2216 Pa.

[0081] In this way, it can be concluded that the preset pressure variation range inside the airship is 150Pa to 2216Pa.

[0082] It should be added that the test system can also include a monitoring device, which can realize real-time monitoring of the strain in the flange and skin test areas by tracking the speckle image on the surface of the airship component. When the strain exceeds the allowable value, it indicates that tiny cracks have occurred in the airship component, the airtightness of the capsule has decreased, and the test is terminated; otherwise, the test can continue.

[0083] In the embodiment of the present application, the preset pressure is a pressure that simulates the airship components under actual working conditions. The preset pressure refers to the pressure inside the airship. The preset pressure is within the pressure variation range and changes with the changes in the airship working environment, such as the temperature and pressure of the airship's environment.

[0084] When the airship is working, the change of ambient temperature will cause the change of pressure inside the airship, and the change of pressure inside the airship will cause the stress on the airship skin to change. Therefore, it is possible to infer through calculation that the corresponding preset temperature and the mechanical force on the airship skin under the preset pressure, and thus the relationship spectrum between the mechanical force, preset temperature and preset pressure can be obtained.

[0085] The airship component testing method of the embodiment of the present application can determine the pressure variation range inside the airship based on the design parameters by obtaining the design parameters of the airship, and select a preset pressure within the pressure variation range, that is, simulate the internal pressure of the airship at a certain moment when it is working, so that the pressure variable can be more consistent with the actual situation of the airship when it is working. According to the preset pressure, the stress magnitude of the airship skin at this time can be inferred. When testing the airship component, the stress magnitude corresponds to the mechanical force that should be applied to the airship component under the preset pressure, so as to simulate the stress of the airship skin when the airship is working under the preset pressure. At the same time, according to the preset pressure, the corresponding ambient temperature of the airship under the preset pressure can be calculated. In this way, when testing, the preset temperature applied to the airship component can be adjusted by the ambient temperature. Thus, the relationship spectrum between mechanical force, preset temperature and preset pressure can be obtained. In this way, the relationship spectrum among mechanical force, preset temperature and preset pressure can be calculated by presetting and adjusting the preset pressure. When conducting a test, the mechanical force and preset temperature that should be applied to the airship components when the internal preset pressure of the airship changes can be determined based on the relationship spectrum, thereby simulating the state of the airship in flight and testing the airship components from both mechanical and temperature aspects, so that the test results of the airship components are more in line with engineering reality, so as to provide experimental support for the optimal design of the airship components.

[0086] based on Figure 1 In one possible embodiment of the present application, referring to Figure 6 , Figure 1 The S200 in Figure 6 Steps S210 to S230 are implemented.

[0087] S210 adjusts the preset pressure based on the pressure variation range;

[0088] S220, based on the adjusted preset pressure, determining a mechanical load spectrum of mechanical force changing with the preset pressure, and a temperature load spectrum of the preset pressure changing with the preset temperature;

[0089] S230 determines a relationship spectrum based on the mechanical load spectrum and the temperature load spectrum.

[0090] In the embodiment of the present application, the mechanical load spectrum can indicate the magnitude of the mechanical force that needs to be applied to the airship components when the airship is at different pressure values. When testing the airship, the mechanical force applied to the airship components can be adjusted by the mechanical load spectrum.

[0091] In the embodiment of the present application, the temperature load spectrum can indicate the magnitude of the preset temperature that needs to be applied to the airship components when the airship is at different pressure values. When testing the airship, the preset temperature applied to the airship components can be adjusted through the temperature load spectrum.

[0092] In the embodiment of the present application, the relationship spectrum can be used to indicate the size of the mechanical force and preset temperature that need to be applied to the airship components when the airship is at different pressure values. When testing the airship, the preset temperature applied to the airship components can be adjusted simultaneously through the relationship spectrum.

[0093] The airship component testing method of the embodiment of the present application can determine the magnitude of the mechanical force and the preset temperature that need to be applied to the airship component corresponding to each preset pressure within the pressure variation range through the relationship spectrum.

[0094] based on Figure 6 In one possible embodiment of the present application, referring to Figure 7 , Figure 6 The S220 can include Figure 7 Steps S221 to S222.

[0095] S221, based on the design parameters, determining a first relationship between the mechanical force and the preset pressure;

[0096] S222 calculates the mechanical force corresponding to each preset pressure based on the first relationship to determine a mechanical load spectrum in which the mechanical force varies with the preset pressure.

[0097] In the embodiment of the present application, the relationship between the mechanical force and the preset pressure can be expressed by a first relationship. The preset pressure is changed within the pressure variation range. The mechanical force corresponding to each preset pressure can be calculated by the first relationship, thereby determining the mechanical load spectrum of the mechanical force as the preset pressure changes.

[0098] based on Figure 7 In one possible embodiment of the present application, referring to Figure 8 , Figure 7 The S221 in Figure 8 Steps S221a to S221c are implemented. Figure 8 The steps shown are explained.

[0099] S221a Based on the design parameters, a stress analysis is performed on the airship component to determine the circumferential curvature and longitudinal curvature of the installation point where the airship component is installed on the airship;

[0100] S221b determines the relationship between the longitudinal stress, the hoop stress and the preset pressure of the airship component based on the hoop curvature and the longitudinal curvature;

[0101] S221c obtains the test parameters of the airship component, and determines a first relationship based on the relationship between the longitudinal stress, the hoop stress and the preset pressure to which the airship component is subjected.

[0102] It should be added that, refer to Fig. 9 and Fig.11 In order to facilitate testing, in the embodiment of the present application, a skin 1 similar to a "cross" shape is used. The middle area of ​​the "cross"-shaped skin 1 is used to install the flange 2 and is located in the temperature control box 3; the "cross"-shaped skin 1 extends in two directions. In order to make the mechanical force on the skin 1 more uniform and reduce the deviation of the center of the skin 1 relative to the temperature control box 3, this embodiment provides two sets of connection components 42 for the "cross"-shaped skin 1.

[0103] Specifically, among the two groups of connection components 42, the direction of the mechanical force applied by one group of connection components 42 to the skin 1 is the first loading direction, which is used to simulate the longitudinal stress to which the airship component is subjected during actual operation; the direction of the mechanical force applied by the other group of connection components 42 to the skin 1 is the second loading direction, which is used to simulate the hoop stress to which the airship component is subjected during actual operation. The first loading direction and the second loading direction are located in the same plane and are perpendicular to each other.

[0104] In addition, refer to Figure 3 and Fig. 9 The loading mechanism 4 also includes a bracket 44 and a second loading component 43, one end of the second loading component 43 is installed on the bracket 44, and the other end is connected to the flange 2, for applying a load to the flange 2; wherein the loading direction of the second loading component 43 is perpendicular to the loading direction of the first loading component 41.

[0105] In the embodiment of the present application, the bracket 44 is used to provide a stable installation platform and support for the second loading assembly 43. The load applied by the second loading assembly 43 to the flange 2 is used to simulate the load of other structures installed on the flange 2 when the airship is in actual working conditions. In the present application, the direction in which the second loading assembly 43 applies the load to the flange 2 is defined as the third loading direction Z. The loading direction of the second loading assembly 43 is perpendicular to the loading direction of the first loading assembly 41. Therefore, the third loading direction Z is perpendicular to the plane where the first loading direction and the second loading direction are located. It can also be understood that the third loading direction Z is perpendicular to the extension direction of the skin 1.

[0106] Based on step S221a, for example, refer to Fig.10 , perform stress analysis on the airship components on the preset airship, Fig.10 P is the pressure difference between the inside and outside of the airship, F X 、F -X 、F Y and F -Y are the tension components along the tangent direction of the airship skin 1; R X and R Y is the radius of curvature of the skin 1 surface in the longitudinal direction (first loading direction X) and the circumferential direction (second loading direction Y); θ and β are the opening angles of the skin 1 in the longitudinal and circumferential directions; l Xand l y It is the side length of the rectangle of the projection of the skin 1 surface in the X, Y plane, and t represents the thickness of skin 1.

[0107] According to formula 1, formula 6 can be obtained:

[0108]

[0109] After analysis, we can get the longitudinal stress σ on the surface of skin 1 X and hoop stress σ y The relationship between the pressure P inside the airship is expressed as formula 7:

[0110]

[0111] Based on step S221b, the relationship between the stress of the double ellipsoidal airship skin 1 and the internal pressure of the airship can be obtained through Formula 3, Formula 6 and Formula 7, which is expressed as Formula 8:

[0112]

[0113] Based on step S221c, for example, when the coordinates of the airship assembly installed on the airship are (10, -37.432), that is, the airship assembly is located at the belly of the hull, and the mass of the payload hanging under flange 2 is 100 kilograms (kg). Fig.11 . T X and T Y The two groups of loading mechanisms 4 apply mechanical forces from the first loading direction X and the second loading direction Y respectively. x , l y They represent the stretching width of the “cross” shaped skin 1 in the corresponding directions, T Z represents the out-of-plane load applied by the out-of-plane load simulation system. The width of the specimen is 0.6 m, and the out-of-plane load simulation system is applied at T Z Keeping the mass of the flange 2 assembly in line, the out-of-plane load system load is always maintained at 1000 Newtons (N).

[0114] Reference Fig.11 The stress state of the airship components during the test should be consistent with that during the actual flight. Therefore, the mechanical forces applied by the two sets of loading mechanisms are respectively proportional to the longitudinal stress σ x , hoop stress σ y According to formula 8, by substituting the results of the airship skin force analysis, the first relationship can be obtained, which is expressed as formula 9. Formula 9 shows the relationship between the mechanical force applied to the airship component by the test system and the internal pressure of the airship.

[0115]

[0116] Among them, σ x is the longitudinal stress on the airship components; σ y is the hoop stress on the airship components; T x T is the longitudinal mechanical force applied by the test system to the airship assembly from the first loading direction; y The lateral mechanical force applied by the test system to the airship assembly from the second loading direction; x is the test parameter of the airship component in the longitudinal direction; l y is the test parameter of the airship assembly in the horizontal direction; t is one of the test parameters of the airship assembly; P is the preset pressure.

[0117] Based on the range of pressure changes inside the airship, the mechanical load spectrum of the mechanical force applied by the test system to the airship components as the pressure inside the airship changes can be calculated using Formula 9. Fig.12 , Fig.12 Shown is the mechanical load spectrum.

[0118] based on Figure 6 In one possible embodiment of the present application, referring to Fig.13 , Figure 6 The S220 can include Fig.13 Steps S223 to S224 in .

[0119] S223, determining a second relationship between the preset temperature and the preset pressure based on the design parameters;

[0120] S224 calculates the preset temperature corresponding to each preset pressure after adjustment based on the second relationship to determine a temperature load spectrum of the preset pressure changing with the preset temperature.

[0121] In the embodiment of the present application, the relationship between the preset temperature and the preset pressure can be expressed by the second relationship. The preset pressure is changed within the pressure variation range. The preset temperature of the machine corresponding to each preset pressure can be calculated by the second relationship, thereby determining the temperature load spectrum of the preset pressure as the preset temperature changes.

[0122] based on Fig.13 In one possible embodiment of the present application, referring to Fig.14 , Fig.13 The S223 in can include Fig.14 Steps S223a to S223b in .

[0123] S223a, based on the design parameters, obtaining the volume change of the airship under the preset pressure;

[0124] S223b obtains the relationship between the preset gas average temperature and the preset gas volume, determines the relationship between the preset pressure and the preset gas average temperature based on the volume change of the airship under the preset pressure, and determines a second relationship.

[0125] In the embodiment of the present application, based on step S223a, for example, a preset airship is selected, and the data of the airship obtained is referred to Table 2:

[0126] Table 2

[0127] Design parameters Numeric Long axis 220 meters (m) Short Axis 75 meters (m) tensile strength 2.7 Elastic modulus 10GPa Poisson's ratio 0.3GPa thickness 0.3mm

[0128] By establishing the finite element analysis of the airship, the change of the airship volume under different airship internal pressure conditions can be obtained, refer to Table 3:

[0129] Table 3

[0130] Pressure(Pa) Airship volume (m3) 0 736000 500 741000 1000 746000 1500 751000 2000 756000

[0131] Analyzing the data in Table 3, it can be concluded that there is a linear relationship between the volume of the airship and the internal pressure of the airship. For every 100Pa increase in the internal pressure of the airship, the volume of the airship increases by about 1000m 3 , can be expressed by formula 10:

[0132] V=V0+KP=736000+10P (10)

[0133] Where: V is the actual volume of the airship, V0 is the designed volume of the airship, P is the hull pressure, and K is the proportional constant between the volume of the airship and the internal pressure of the airship.

[0134] During the flight of the airship, it is affected by many factors, including direct solar radiation, scattered sky radiation, reflected radiation from the ground, atmospheric infrared radiation, earth infrared radiation, and convective heat transfer. Fig.15 , where the day and night changes in solar radiation will directly affect the helium inside the airship (the buoyancy gas inside the airship is assumed to be helium as shown in Table 1) and the temperature change of the capsule surface, resulting in changes in the pressure, volume and buoyancy of the hull. Once the hull pressure rises to the upper limit, the convective heat exchange between the shell and the environment can be increased by increasing the flight speed to reduce the temperature of the airship. At the same time, by discharging part of the air in the air bag inside the airship, the pressure of the airship is maintained to improve the safety of the airship structure.

[0135] Reference Fig.15, after the airship enters the level flight stage, assuming that the air in the air bag is completely exhausted and the airship is completely filled with helium, the thermodynamic environment of the airship in the stationary stage. The airship is affected by direct solar radiation, scattered radiation from the sky, reflected radiation from the ground, long-wave radiation from the atmosphere, long-wave emission from the ground, natural convection heat exchange between the airship and the internal gas, and external mixed convection heat dissipation. During the fixed-point flight, the solar radiation changes periodically during the day and night, causing the airship skin 1 temperature and the internal gas temperature to change during the day and night. During the day, the airship is affected by solar radiation, reflected radiation from the ground, and ground infrared radiation. The density of the stratosphere is very small, and the strong solar radiation and weak convection heat exchange cause the airship to "overheat". At night, due to the lack of solar radiation, the airship is in a low-temperature atmospheric environment. Due to the convection heat exchange and atmospheric infrared radiation, the airship shell and internal gas temperature will drop significantly.

[0136] In the embodiment of the present application, a method for quickly calculating the average temperature variation range of helium in an airship is proposed, specifically:

[0137] Based on step S223b, for example, after the airship enters the level flight stage, assuming that the air in the air bag is completely exhausted and the airship is completely filled with helium, that is, the volume of helium is equal to the volume of the airship, the relationship between the volume, pressure and temperature of helium can be obtained through the ideal gas state equation, which can be expressed by formula 11:

[0138]

[0139] n in formula 11 he It can be calculated by formula 12, which is:

[0140]

[0141] Where: P he is the helium pressure, V he is the volume, n he is the amount of helium, R is the molar gas constant, T he is the average temperature of helium, μ is the molar mass of helium, m he is the mass of helium.

[0142] Formula 13 can be derived from Formula 11:

[0143]

[0144] Among them, P air represents the atmospheric pressure outside the airship, V0 is the initial volume of the airship, K v is the proportional constant between volume and hull pressure. The second relationship can be derived by deduction. The second relationship is expressed as formula 13:

[0145]

[0146] Among them, P air is the atmospheric pressure outside the airship; V is the initial volume of the airship; K v is the proportional constant between volume and internal pressure of the airship; m he is the preset gas mass; μ is the molar mass of the preset gas; R is the molar gas constant; P is the preset pressure, T he is the average temperature of the preset gas.

[0147] On this basis, since the airship is affected by environmental factors during flight, at sunrise, the east side of the airship facing the sun is suddenly radiated by the sun, and the temperature of the sunny side of the skin 1 rises sharply, while the lowest temperature of the shady side of the airship rises slowly. With the heat exchange between the skin 1 and the internal gas, the highest temperature of the airship skin 1 will decrease again, while the lowest temperature of the skin 1 will continue to rise. In the embodiment of the present application, the maximum temperature difference on the surface of the airship is about 60K (K is the temperature unit "Kelvin"). Therefore, if the flange 2 assembly is installed on the upper surface of the hull, the temperature of the flange 2 assembly is 30K higher than the average temperature of helium. Conversely, when the flange 2 assembly is installed on the lower surface of the hull, the temperature of the flange 2 assembly is 30K lower than the temperature of helium. That is, the preset temperature can be adjusted by formula 14, which is expressed as:

[0148]

[0149] Based on the range of pressure changes inside the airship, the temperature load spectrum of the preset temperature and pressure changes inside the airship applied by the test system to the airship components can be calculated by formula 14. Fig.16 , Fig.16 Shown is the temperature load spectrum.

[0150] In addition, in the embodiment of the present application, since the average temperature of helium remains unchanged at night, this is because the ambient temperature and thermal radiation environment remain unchanged at night. The average temperature of helium rises rapidly after sunrise, reaches its highest point at noon, decreases in the afternoon, and drops rapidly after sunset. However, due to the obstruction of the hull, the temperature of the lower surface of the airship rises relatively slowly, reaching its highest temperature at midday, and then gradually decreases. Therefore, it can be obtained that the temperature of the flange 2 component rises uniformly from the lowest temperature to the highest temperature within 7 hours, and then cools down at the same rate, and the loading is cyclically repeated. Using the hull pressure as the intermediate variable, the relationship spectrum is obtained, referring to Fig.17 .

[0151] based on Figure 6 In one possible embodiment of the present application, referring to Fig.18 , Figure 6 The S210 in Fig.18 Steps S211 to S213 in are implemented.

[0152] S211 determines the number of test repetitions based on the pressure variation range;

[0153] S212 determines, according to the number of repetitions, a preset difference value by which the preset pressure needs to be adjusted in each test repetition;

[0154] S213 calculates a preset pressure for repeated testing based on the preset difference.

[0155] In the embodiment of the present application, according to the pressure variation range, the number of times the preset pressure of the airship component is repeatedly adjusted during the test can be determined, and the preset difference value that needs to be adjusted each time the preset pressure is adjusted can be determined according to the number of times. During the test process, the preset pressure can be adjusted by adding or subtracting the preset difference value each time it is adjusted.

[0156] based on Figure 6 In one possible embodiment of the present application, referring to Fig.19 , Figure 6 The S220 in Fig.19 Steps S225 to S227 in are implemented.

[0157] S225 determines whether the preset pressure is within the pressure variation range;

[0158] S226: When the preset pressure is within the pressure variation range, adjusting the preset pressure according to the preset difference, and determining a mechanical load spectrum of mechanical force varying with the preset pressure, and a temperature load spectrum of the preset pressure varying with the preset temperature;

[0159] S227 ends the test when the preset pressure is outside the pressure variation range.

[0160] based on Figure 1 In one possible embodiment of the present application, referring to Fig. 20 , Figure 1 The S300 can include Fig. 20 Steps S310 to S340 in .

[0161] S310 builds the test system and inputs the relationship spectrum;

[0162] S320 conducted a preliminary experiment based on the relationship spectrum;

[0163] S330 applies a mechanical force corresponding to an initial preset pressure and a preset temperature to the airship component based on the relationship spectrum;

[0164] S340 adjusts the preset pressure based on the pressure variation range, and repeatedly applies a mechanical force and a preset temperature corresponding to the current preset pressure to the airship component.

[0165] In the embodiment of the present application, based on step S310, refer to Fig. 9 and Fig.10 Before the test, a system for testing is built, and the flange 2 is installed in the central area of ​​the "cross" diaphragm. The two opposite sides of the "cross" diaphragm are a group, one of which is connected to the first loading component 41 through the connecting component 42, and the other group is connected to the second loading component 43 through the connecting component 42; a lifting ring interface is left on the top of the flange 2, which is connected to the third loading mechanism 4 through a wire rope.

[0166] In addition, the loading mechanism 4 also includes equipment such as a gear transmission system, a laser rangefinder and a dynamometer; the temperature control box 3 includes equipment such as an upper cover plate, liquid nitrogen, a heating plate, a temperature collector and a valve; the test system also includes a three-dimensional full-field strain measurement system installation integration 5 and a central control system 6, including a three-dimensional strain measuring instrument probe and a data collector; the loading mechanism 4, the temperature control box 3, and the three-dimensional full-field strain measurement system installation integration 5 are connected to the central control system 6.

[0167] based on Figure 1 , refer to Fig.21 , Figure 1 The S300 can also include Fig.21 Steps S350 to S370 in .

[0168] S350 determines the relationship between the deformation amount of the skin 1 of the airship assembly and the limit value of the deformation of the skin 1;

[0169] When the deformation of skin 1 is less than the limit value of skin 1 deformation, S360 adjusts the preset pressure and continues the test;

[0170] S370 ends the test when the deformation of the skin 1 is greater than the limit value of the deformation of the skin 1.

[0171] In addition, it is also possible to determine whether to continue the test cycle or end the test by judging whether the number of test cycles reaches the limit value. Fig.21 When the deformation of the skin 1 is less than the limit value of the deformation of the skin 1, the judgment is continued, and the specific steps are as follows S360a to S360b:

[0172] The number of S360a test cycles did not reach the limit value, so the preset pressure was adjusted and the test continued;

[0173] S360b The number of test cycles reaches the limit and the test ends.

[0174] It should be added that, refer to Fig. 22After the test is completed, the test data can be post-processed. You can first make a strain video of the entire test process, compare the changes in the stress around the airship components before and after the test, conduct a cyclic loading test again, conduct a residual strength test and air tightness test on the airship components, analyze whether there are any abnormalities during the test, and write a test report.

[0175] based on Fig. 20 In one possible embodiment of the present application, referring to Fig.23 , Fig. 20 The S320 can include Fig.23 Steps S321 to S323 in .

[0176] S321 gradually increases the mechanical force applied to the airship component to a maximum value based on the relationship spectrum;

[0177] S322 gradually reduces the preset temperature applied to the airship component to a minimum value based on the relationship spectrum;

[0178] S323 obtains the test data of the airship components in the preliminary experiment in real time.

[0179] In the embodiment of the present application, the pre-test test is controlled by the central control system 6, and the mechanical force applied to the airship assembly by the first loading system and the second loading system is loaded step by step from zero to the maximum value, and then the mechanical force applied to the airship assembly by the third loading system is loaded step by step from zero to the maximum value, and then the preset temperature in the temperature control box 3 is gradually reduced from normal temperature to the minimum value. During the adjustment process, the three-dimensional strain measurement system is turned on for real-time monitoring. After the mechanical force and the preset temperature reach the limit value, the initial state is restored, and the formal test can be started after the measurement is repeated three times.

[0180] The serial numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments. The above are only preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for testing airship components, characterized in that: include: Acquiring design parameters of the airship, and determining a pressure variation range inside the airship and a preset pressure within the pressure variation range based on the design parameters; Based on the pressure variation range, determining a relationship spectrum between the mechanical force, the preset temperature and the preset pressure to which the airship component is subjected; Based on the relationship spectrum, a test system is controlled to apply the mechanical force and the preset temperature to the airship component, and a test result is obtained.

2. The airship component testing method according to claim 1, characterized in that: In the step of determining the relationship spectrum between the mechanical force, the preset temperature and the preset pressure borne by the airship component based on the pressure variation range, the testing method includes: adjusting the preset pressure based on the pressure variation range; Based on the adjusted preset pressure, determining a mechanical load spectrum of the mechanical force as the preset pressure changes, and a temperature load spectrum of the preset pressure as the preset temperature changes; The relationship spectrum is determined based on the mechanical load spectrum and the temperature load spectrum.

3. The airship component testing method according to claim 2, characterized in that: In the step of determining the mechanical load spectrum of the mechanical force changing with the preset pressure and the temperature load spectrum of the preset pressure changing with the preset temperature based on the adjusted preset pressure, the testing method comprises: Based on the design parameters, determining a first relationship between the mechanical force and the preset pressure; Based on the first relationship, the mechanical force corresponding to each of the preset pressures is calculated to determine a mechanical load spectrum in which the mechanical force varies with the preset pressure.

4. The airship component testing method according to claim 3, characterized in that: In the step of determining a first relationship between the mechanical force and the preset pressure based on the design parameters, the testing method comprises: Based on the design parameters, a force analysis is performed on the airship component to determine the circumferential curvature and the longitudinal curvature of the installation point where the airship component is installed on the airship; Based on the annular curvature and the longitudinal curvature, determining the relationship between the longitudinal stress, the annular stress and the preset pressure to which the airship component is subjected; The test parameters of the airship component are obtained, and the first relationship is determined based on the relationship between the longitudinal stress, the hoop stress and the preset pressure to which the airship component is subjected.

5. The airship component testing method according to claim 3 or 4, characterized in that: The first relation is: Among them, σ x is the longitudinal stress on the airship assembly; σ y is the hoop stress of the airship assembly; T x T is the longitudinal mechanical force applied by the test system to the airship assembly; y is the lateral mechanical force applied by the test system to the airship assembly; x is the test parameter of the airship assembly in the longitudinal direction; l y is the test parameter of the airship assembly in the lateral direction; t is one of the test parameters of the airship assembly; and P is the preset pressure.

6. The airship component testing method according to claim 2, characterized in that: In the step of determining the mechanical load spectrum of the mechanical force changing with the preset pressure and the temperature load spectrum of the preset pressure changing with the preset temperature based on the adjusted preset pressure, the testing method further comprises: Based on the design parameters, determining a second relationship between the preset temperature and the preset pressure; Based on the second relationship, the preset temperature corresponding to each of the preset pressures after adjustment is calculated to determine a temperature load spectrum of the preset pressures changing with the preset temperatures.

7. The airship component testing method according to claim 6, characterized in that: In the step of determining a second relationship between the preset temperature and the preset pressure based on the design parameters, the testing method includes: Based on the design parameters, obtaining a volume change of the airship under the preset pressure; The relationship between the preset gas average temperature and the preset gas volume is obtained, and based on the volume change of the airship under the preset pressure, the relationship between the preset pressure and the preset gas average temperature is determined, and a second relationship is determined.

8. The airship component testing method according to claim 6 or 7, characterized in that: The second relation is: Among them, P air is the atmospheric pressure outside the airship; V0 is the initial volume of the airship; K is the proportional constant between the volume and the internal pressure of the airship; m he is the preset gas mass; μ is the molar mass of the preset gas; R is the molar gas constant; P is the preset pressure, T he is the average temperature of the preset gas.

9. The airship component testing method according to claim 2, characterized in that: In the step of adjusting the preset pressure based on the pressure variation range, the testing method includes: Based on the pressure variation range, determining the number of test repetitions; Determining, according to the number of repetitions, a preset difference value by which the preset pressure needs to be adjusted each time the test is repeated; Based on the predetermined difference, the predetermined pressure for repeating the test is calculated.

10. The airship component testing method according to claim 9, characterized in that: In the step of determining the mechanical load spectrum of the mechanical force changing with the preset pressure and the temperature load spectrum of the preset pressure changing with the preset temperature based on the adjusted preset pressure, the testing method comprises: Determining whether the preset pressure is within the pressure variation range; When the preset pressure is within the pressure variation range, adjusting the preset pressure according to the preset difference, and determining a mechanical load spectrum of the mechanical force varying with the preset pressure, and a temperature load spectrum of the preset pressure varying with the preset temperature; When the preset pressure is outside the pressure variation range, the test is terminated.

11. The airship component testing method according to claim 1, characterized in that: In the step of controlling the test system to apply the mechanical force and the preset temperature to the airship component based on the relationship spectrum and obtaining the test result, the test method includes: Building the test system and inputting the relationship spectrum; Conducting a preliminary experiment based on the relationship spectrum; Based on the relationship spectrum, applying the mechanical force and the preset temperature corresponding to the initial preset pressure to the airship component; The preset pressure is adjusted based on the pressure variation range, and the mechanical force and the preset temperature corresponding to the current preset pressure are repeatedly applied to the airship component.

12. The airship component testing method according to claim 11, characterized in that: In the step of controlling the test system to apply the mechanical force and the preset temperature to the airship component based on the relationship spectrum and obtaining the test result, the test method further includes: Determining the relationship between the amount of skin deformation of the airship assembly and the limit value of the skin deformation; When the skin deformation is less than the skin deformation limit value, adjusting the preset pressure and continuing the test; When the skin deformation is greater than the skin deformation limit value, the test is terminated.

13. The airship component testing method according to claim 9, characterized in that: In the preliminary experiment step based on the relationship spectrum, the test method includes: Based on the relationship spectrum, gradually increasing the mechanical force applied to the airship component to a maximum value; Based on the relationship spectrum, gradually reducing the preset temperature applied to the airship component to a minimum value; The test data of the airship component in the preliminary experiment is obtained in real time.

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