A method and device for designing random vibration test conditions of an accumulator bellows

Abstract

The application provides a kind of accumulator membrane box random vibration test condition design method and device, comprising: obtaining the high-frequency vibration acceleration flight telemetry time domain data of accumulator membrane box and accumulator shell mounting interface;Select multiple flight smooth section time domain data for band-pass filtering, and make power spectral density processing analysis;Multiple flight smooth section power spectral density data are maximum envelope processing;Based on flight smooth section power spectral density maximum envelope data, design acceptance level random vibration test condition;Based on acceptance level random vibration test condition, determine the identification level random vibration test condition, complete accumulator membrane box random vibration test condition design.The random vibration test condition of the accumulator membrane box is obtained by the design when the ground vibration test is carried out alone, which can improve the over-test condition of the accumulator membrane box caused by the ground vibration test of the whole accumulator, and reduce the structure design difficulty and ground over-test risk of the accumulator membrane box.

Description

Technical Field

[0001] This invention belongs to the field of launch vehicle technology, and specifically relates to a method and apparatus for designing random vibration test conditions for accumulator diaphragm boxes. By designing random vibration test conditions for accumulator diaphragm boxes to be tested on the ground independently, the invention can improve the overtesting situation of accumulator diaphragm boxes caused by the overall ground vibration test of the accumulator, and reduce the structural design difficulty and risk of overtesting of the accumulator diaphragm boxes. Background Technology

[0002] The accumulator is a crucial component of a launch vehicle's propulsion system. During the active flight phase, it endures continuous high-frequency (20–2000 Hz) random vibrations generated throughout the engine's operation. Therefore, the structural design of the accumulator requires conducting corresponding mechanical environmental analysis based on the high-frequency random vibration conditions provided by the overall launch system design. Ground-based mechanical tests are also necessary to ensure the accumulator's adaptability to the high-frequency random vibration environment during flight. Thus, the rationality of the random vibration test conditions provided by the overall launch system design significantly impacts the accumulator's design and development.

[0003] Launch vehicle design typically involves high-frequency (20–2000 Hz) vibration testing based on the interface between the accumulator casing's lower end face and the rocket body. Since the accumulator is installed at the engine propellant inlet, it is subjected to continuous excitation throughout engine operation, resulting in a harsh mechanical environment. After the accumulator design is completed, ground vibration tests are conducted to verify its performance under the high-frequency vibration conditions specified by the launch vehicle design. Due to differences in the constraint boundaries between ground and flight conditions, the response amplification of critical internal locations relative to the lower end face of the casing is significantly greater under ground vibration testing than under flight conditions. This is especially true for the crucial diaphragm assembly, which is extremely sensitive to vibration; excessive vibration excitation can easily lead to structural damage. Therefore, the diaphragm assembly exhibits severe over-testing under current test conditions, further complicating its design. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the inventors have conducted intensive research and provided a method and device for designing random vibration test conditions for accumulator diaphragms. By designing the random vibration test conditions when the accumulator diaphragm is subjected to ground vibration test alone, the overtesting of the accumulator diaphragm caused by the overall ground vibration test of the accumulator can be improved, and the structural design difficulty of the accumulator diaphragm and the risk of overtesting on the ground can be reduced.

[0005] The technical solution provided by this invention is as follows:

[0006] In a first aspect, a method for designing random vibration test conditions for an accumulator diaphragm includes the following steps:

[0007] Based on the flight telemetry data of the launch vehicle, the high-frequency vibration acceleration flight telemetry time domain data of the installation interface between the accumulator diaphragm and the accumulator shell were obtained;

[0008] Based on the high-frequency vibration acceleration flight telemetry time-domain data of the accumulator diaphragm and accumulator housing mounting interface, multiple segments of time-domain data during stable flight periods were selected for bandpass filtering, and the filtered data were then processed and analyzed for power spectral density.

[0009] The power spectral density data of multiple stable flight segments are processed by the maximum envelope to obtain the maximum envelope data of the power spectral density of the stable flight segments.

[0010] Based on the maximum envelope data of power spectral density during the steady flight phase, the power spectral density order of the acceptance-level random vibration test is designed, and the random vibration time for the acceptance-level test is specified.

[0011] Multiply the power spectral density of the acceptance-level random vibration test by a safety factor to obtain the power spectral density of the qualification-level random vibration test, and specify the qualification-level random vibration time to complete the design of the random vibration test conditions for the accumulator diaphragm.

[0012] Secondly, a device for designing random vibration test conditions for an accumulator diaphragm includes:

[0013] The first module is used to obtain high-frequency vibration acceleration flight telemetry time-domain data of the accumulator diaphragm and accumulator housing installation interface based on the launch vehicle flight telemetry data;

[0014] The second module is used to select multiple segments of time domain data from the flight telemetry based on the high-frequency vibration acceleration flight time domain data of the accumulator diaphragm and accumulator housing mounting interface, perform bandpass filtering, and then perform power spectral density processing and analysis on the filtered data.

[0015] The third module is used to perform maximum envelope processing on the power spectral density data of multiple stable flight segments to obtain the maximum envelope data of the power spectral density of the stable flight segments.

[0016] The fourth module is used to design the power spectral density order of acceptance-level random vibration tests based on the maximum envelope data of power spectral density during the stable flight phase, and to specify the random vibration time for acceptance-level tests.

[0017] The fifth module is used to multiply the power spectral density magnitude of the acceptance-level random vibration test by a safety factor to obtain the power spectral density magnitude of the qualification-level random vibration test, and to specify the qualification-level random vibration time.

[0018] Thirdly, an apparatus for designing random vibration test conditions for an accumulator diaphragm includes:

[0019] One or more processors;

[0020] Storage device for storing one or more programs.

[0021] When the one or more programs are executed by the one or more processors, the one or more processors implement the random vibration test condition design method for accumulator diaphragm as described in the first aspect.

[0022] Fourthly, a readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for designing random vibration test conditions for accumulator diaphragms as described in the first aspect.

[0023] The method and apparatus for designing random vibration test conditions for accumulator diaphragms provided by the present invention have the following beneficial effects:

[0024] This invention provides a method and apparatus for designing random vibration test conditions for accumulator diaphragms. It involves performing power spectral density analysis on high-frequency vibration acceleration flight telemetry time-domain data from the accumulator diaphragm-housing interface during the stable flight phase, after bandpass filtering (20-2000Hz). The resulting power spectral density data from multiple stable flight phases are then subjected to maximum envelope processing. Based on this envelope data, corresponding acceptance-level and qualification-level random vibration test conditions are designed. This invention, by designing random vibration test conditions for accumulator diaphragms to undergo ground vibration testing alone, can improve the situation of accumulator diaphragms over-testing caused by conducting ground vibration tests on the entire accumulator, reducing the structural design difficulty of the accumulator diaphragm and the risk of over-testing on the ground. Attached Figure Description

[0025] Figure 1 This is a flowchart of the method for designing random vibration test conditions for accumulator diaphragms.

[0026] Figure 2 It is the time-domain curve of high-frequency vibration flight telemetry at the interface between the diaphragm box and the accumulator shell of the first-stage accumulator of the launch vehicle core.

[0027] Figure 3 These are power spectral density curves for multiple stable flight segments.

[0028] Figure 4 It is the maximum envelope curve of power spectral density during the stable flight phase of multiple segments.

[0029] Figure 5 It is the random vibration test condition curve for the accumulator diaphragm box acceptance level.

[0030] Figure 6 These are the random vibration test condition curves for the accumulator diaphragm box qualification / acceptance level. Detailed Implementation

[0031] The features and advantages of the present invention will become clearer and more explicit from the following detailed description.

[0032] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments. Although various aspects of embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated otherwise.

[0033] This invention provides a method for designing random vibration test conditions for accumulator diaphragms, such as... Figure 1 As shown, it includes the following steps:

[0034] Step 1: Based on the launch vehicle flight telemetry data, obtain the high-frequency vibration acceleration flight telemetry time-domain data of the accumulator diaphragm and accumulator housing mounting interface. The specific implementation steps are as follows: In this example, based on the launch vehicle flight telemetry data, obtain the high-frequency vibration flight telemetry time-domain data of the core stage accumulator diaphragm and accumulator housing mounting interface measured by a high-frequency vibration sensor (20-2000Hz), and perform preprocessing by removing the center term. The resulting time-domain data curve is shown below. Figure 2 As shown.

[0035] Step 2: Based on the high-frequency vibration acceleration flight telemetry time-domain data of the accumulator diaphragm and accumulator housing installation interface obtained in Step 1, select multiple segments of time-domain data from the stable flight period and perform bandpass filtering from 20 to 2000 Hz. Then, perform power spectral density processing and analysis on the filtered data.

[0036] The specific implementation steps are as follows: According to Figure 2 The time-domain data shown uses the initial, middle, and final phases of the core-first-stage engine's operation as typical stable flight segments for analysis. In this example, the initial phase of core-first-stage engine operation is 6s–9s, the middle phase is 100s–103s, and the final phase is 233s–236s. After bandpass filtering the selected stable flight segment data from 20 to 2000Hz, the power spectral density method in Appendix K of "GJB 2238A_2004 Telemetry Data Processing" is used to process and analyze the filtered data, resulting in the power spectral density curves for each stable flight segment, as shown below. Figure 3 As shown.

[0037] Step 3: Based on the power spectral density data of multiple flight stability segments obtained in Step 2, perform maximum envelope processing. The specific implementation steps are as follows: Take the maximum value of each flight stability segment power spectral density data obtained in Step 2 at each same frequency to obtain the maximum envelope curve of the flight stability segment power spectral density data, as shown below. Figure 4 As shown.

[0038] Step 4: Based on the maximum envelope data of the power spectral density during the stable flight phase obtained in Step 3, design the power spectral density order of the acceptance-level random vibration test (e.g., 0.02g at 2Hz). 2 / Hz, at 100Hz the order of magnitude is 0.1g. 2 / Hz, at 1000Hz the order of magnitude is 0.1g. 2 / Hz), and the corresponding frequency-power spectral density curve of the acceptance-level random vibration test is obtained. The acceptance-level random vibration time is specified as the engine operating time. The specific implementation steps are as follows: Based on the maximum envelope of the power spectral density data of each flight steady segment, and considering a certain engineering margin, the magnitude of the acceptance-level random vibration test and the frequency-power spectral density curve of the acceptance-level random vibration test are designed as follows: Figure 5 As shown, the random vibration time for acceptance testing is specified as 240 seconds of the core engine's operating time.

[0039] Step 5: Multiply the power spectral density magnitude of the acceptance-level random vibration test obtained in Step 4 by a safety factor of 2 to 4 to obtain the magnitude of the qualification-level random vibration test. The qualification-level random vibration time is specified as 60 ± 5 seconds longer than the acceptance-level vibration test time. The specific implementation steps are as follows: In this example, a safety factor of 2.5 is used as the qualification margin. The spectral density magnitude of the designed random vibration test is multiplied by a factor of 2.5 to obtain the magnitude of the qualification-level random vibration test. Figure 6 As shown. In this example, the random vibration time for the identification level is 300s.

[0040] The present invention also provides a device for designing random vibration test conditions for an accumulator diaphragm, comprising:

[0041] The first module is used to obtain high-frequency vibration acceleration flight telemetry time-domain data of the accumulator diaphragm and accumulator housing installation interface based on the launch vehicle flight telemetry data;

[0042] The second module is used to select multiple segments of time domain data from the flight telemetry based on the high-frequency vibration acceleration flight time domain data of the accumulator diaphragm and accumulator housing mounting interface, perform bandpass filtering, and then perform power spectral density processing and analysis on the filtered data.

[0043] The third module is used to perform maximum envelope processing on the power spectral density data of multiple stable flight segments to obtain the maximum envelope data of the power spectral density of the stable flight segments.

[0044] The fourth module is used to design the power spectral density order of acceptance-level random vibration tests based on the maximum envelope data of power spectral density during the stable flight phase, and to specify the random vibration time for acceptance-level tests.

[0045] The fifth module is used to multiply the power spectral density magnitude of the acceptance-level random vibration test by a safety factor to obtain the power spectral density magnitude of the qualification-level random vibration test, and to specify the qualification-level random vibration time.

[0046] The present invention also provides a device for designing random vibration test conditions for an accumulator diaphragm, comprising:

[0047] One or more processors;

[0048] Storage device for storing one or more programs.

[0049] When the one or more programs are executed by the one or more processors, the one or more processors implement the random vibration test condition design method for accumulator diaphragm as described in the first aspect.

[0050] The present invention also provides a readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for designing random vibration test conditions for accumulator diaphragms as described in the first aspect.

[0051] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the devices, equipment, and readable storage media described above can be referred to the corresponding processes in the aforementioned methods, and will not be repeated here.

[0052] The apparatus, device, and readable storage medium technical solutions of this application, in essence, or in terms of their contribution to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0053] Those skilled in the art will recognize that, in one or more of the examples above, the functions described in this invention can be implemented using hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium accessible to a general-purpose or special-purpose computer.

[0054] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0055] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for designing random vibration test conditions for an accumulator diaphragm, characterized in that, Includes the following steps: Based on the flight telemetry data of the launch vehicle, the high-frequency vibration acceleration flight telemetry time domain data of the installation interface between the accumulator diaphragm and the accumulator shell were obtained; Based on the high-frequency vibration acceleration flight telemetry time-domain data of the accumulator diaphragm and accumulator housing mounting interface, multiple segments of time-domain data during stable flight periods were selected for bandpass filtering, and the filtered data were then processed and analyzed for power spectral density. The maximum envelope processing is performed on the power spectral density data of multiple flight steady segments to obtain the maximum envelope data of the power spectral density of the flight steady segments. This is done by taking the maximum value of the power spectral density data of each flight steady segment at each same frequency. Based on the maximum envelope data of power spectral density during the steady flight phase, the power spectral density order of the acceptance-level random vibration test is designed, and the random vibration time for the acceptance-level test is specified. Multiply the power spectral density of the acceptance-level random vibration test by a safety factor to obtain the power spectral density of the qualification-level random vibration test, and specify the qualification-level random vibration time to complete the design of the random vibration test conditions for the accumulator diaphragm.

2. The method for designing random vibration test conditions for an accumulator diaphragm according to claim 1, characterized in that, In the step of selecting multiple segments of stable flight time domain data for bandpass filtering, multiple segments of stable flight time domain data are selected for bandpass filtering at 20~2000Hz.

3. The method for designing random vibration test conditions for an accumulator diaphragm according to claim 1, characterized in that, The step of performing power spectral density processing and analysis on the filtered data is implemented in the following manner: the power spectral density method in Appendix K of "GJB 2238A_2004 Telemetry Data Processing" is used to perform power spectral density processing and analysis on the filtered data.

4. The method for designing random vibration test conditions for an accumulator diaphragm according to claim 1, characterized in that, In the step of designing the power spectral density order of the acceptance-level random vibration test based on the maximum envelope data of the power spectral density during the flight steady segment, and specifying the random vibration time of the acceptance-level test, the random vibration time of the acceptance-level test is the engine operating time.

5. The method for designing random vibration test conditions for an accumulator diaphragm according to claim 1, characterized in that, In the step of multiplying the power spectral density magnitude of the acceptance-level random vibration test by a safety factor to obtain the power spectral density magnitude of the qualification-level random vibration test, and specifying the qualification-level random vibration time, the safety factor is 2 to 4 times.

6. The method for designing random vibration test conditions for an accumulator diaphragm according to claim 1, characterized in that, In the step of multiplying the power spectral density of the acceptance-level random vibration test by a safety factor to obtain the power spectral density of the qualification-level random vibration test, and specifying the qualification-level random vibration time, the qualification-level random vibration time is 60±5 seconds longer than the acceptance-level vibration test time.

7. A device for designing random vibration test conditions for an accumulator diaphragm, characterized in that, include: The first module is used to obtain high-frequency vibration acceleration flight telemetry time-domain data of the accumulator diaphragm and accumulator housing installation interface based on the launch vehicle flight telemetry data; The second module is used to select multiple segments of time domain data from the flight telemetry based on the high-frequency vibration acceleration flight time domain data of the accumulator diaphragm and accumulator housing mounting interface, perform bandpass filtering, and then perform power spectral density processing and analysis on the filtered data. The third module is used to perform maximum envelope processing on the power spectral density data of multiple flight steady segments to obtain the maximum envelope data of the power spectral density of the flight steady segments. This is implemented in the following way: the maximum value of the power spectral density data of each flight steady segment is taken at each same frequency to obtain the maximum envelope data of the power spectral density of the flight steady segments. The fourth module is used to design the power spectral density order of acceptance-level random vibration tests based on the maximum envelope data of power spectral density during the stable flight phase, and to specify the random vibration time for acceptance-level tests. The fifth module is used to multiply the power spectral density magnitude of the acceptance-level random vibration test by a safety factor to obtain the power spectral density magnitude of the qualification-level random vibration test, and to specify the qualification-level random vibration time.

8. A device for designing random vibration test conditions for an accumulator diaphragm, characterized in that, include: One or more processors; Storage device for storing one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement the method for designing random vibration test conditions for accumulator diaphragms as described in any one of claims 1 to 6.

9. A readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the method for designing random vibration test conditions for an accumulator diaphragm as described in any one of claims 1 to 6.

Images