A method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment
By acquiring vibration response data from engine ground tests, performing preprocessing and equivalent sinusoidal processing, and combining longitudinal transmission characteristics and safety factors, the problem of difficulty in quickly providing longitudinal sinusoidal vibration test conditions in the early stages of new rocket design was solved, enabling rapid and accurate design of rocket schemes and selection of individual equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI AEROSPACE SYST ENG INST
- Filing Date
- 2023-04-17
- Publication Date
- 2026-07-17
AI Technical Summary
Existing technologies are insufficient to quickly provide accurate longitudinal sinusoidal vibration test conditions in the early stages of new launch vehicle design, leading to difficulties in rocket scheme demonstration and single-unit equipment selection, and simulation prediction consumes a lot of time and effort.
By acquiring vibration response data from engine ground tests, preprocessing and equivalent sinusoidal processing are performed. Combined with longitudinal transmission characteristics and safety factors, longitudinal sinusoidal vibration test conditions for each section of the launch vehicle can be quickly designed.
It enables the rapid provision of accurate longitudinal sinusoidal vibration test conditions during the demonstration phase of new rocket programs, ensuring the selection and design quality of individual equipment and improving the efficiency and reliability of rocket design.
Smart Images
Figure CN116754160B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of launch vehicle technology, and in particular relates to a method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment. Background Technology
[0002] The longitudinal sinusoidal vibration environment experienced by individual components on a launch vehicle during the launch phase mainly involves thrust changes and stage separation during engine ignition and shutdown, which excite transient low-frequency vibration responses in the rocket structure and onboard instruments. Damage or failure of these individual components is closely related to the low-frequency sinusoidal vibration environment they endure. The accuracy of test conditions directly affects the product design level and the effectiveness of ground tests, thus influencing the quality of individual components. This is one of the key factors determining the success or failure of rocket flight.
[0003] Current methods for designing sinusoidal vibration test conditions primarily rely on measured environmental data. With a large amount of available measured environmental data, statistical methods are used to analyze this data and apply appropriate envelopes to formulate corresponding test conditions. However, a large amount of measured environmental data can only be obtained after the rocket has been manufactured and undergone multiple flight tests. Test conditions, on the other hand, are always required before rocket design to verify the environmental adaptability of individual components. Therefore, to meet the needs of new rocket design, test conditions must be completed under conditions lacking measured environmental data for the new rocket; the required environment can only be determined through simulation. Finite element analysis is commonly used for simulation, but the analysis model needs thorough verification to ensure the validity of the calculations. Furthermore, simulation simulation requires significant time and effort, causing considerable inconvenience for the rapid demonstration of new rocket designs. Summary of the Invention
[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment. This method can quickly provide longitudinal sinusoidal vibration test conditions for individual equipment on each section of the launch vehicle in the early stages of launch vehicle demonstration and design, so as to facilitate the selection of individual equipment and the design of the scheme.
[0005] To address the aforementioned technical problems, this invention discloses a method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment, comprising:
[0006] Step 1: Obtain the time-domain vibration response curves of the engine's normal mounting base or the docking point between the engine frame and the compartment during ground testing.
[0007] Step 2: Preprocess the vibration response time-domain curve obtained in Step 1 to obtain the equivalent sinusoidal data of the impact response spectrum;
[0008] Step 3: Envelope the equivalent sinusoidal data of the impact response spectrum obtained in Step 2, and determine the envelope result as the acceptance level longitudinal sinusoidal vibration test level for instruments and equipment on the tail section of the launch vehicle.
[0009] Step 4: Based on the longitudinal transmission characteristics, and using the longitudinal sinusoidal vibration test magnitude of the instruments and equipment on the tail section of the launch vehicle determined in Step 3, combined with the attenuation coefficient of the longitudinal transmission characteristics, obtain the longitudinal sinusoidal vibration test magnitude of the instruments and equipment on other sections of the launch vehicle.
[0010] Step 5: Multiply the acceptance-level longitudinal sinusoidal vibration test magnitude of the instruments and equipment on the tail section of the launch vehicle determined in Step 3 and the acceptance-level longitudinal sinusoidal vibration test magnitude of the instruments and equipment on other sections of the launch vehicle obtained in Step 4 by the safety factor T to obtain the evaluation-level longitudinal sinusoidal vibration test magnitude.
[0011] In the above-mentioned design method for longitudinal sinusoidal vibration test conditions of launch vehicle instruments and equipment, the vibration response time-domain curve obtained in step 1 is preprocessed to obtain equivalent sinusoidal data of the impact response spectrum, including:
[0012] The time-domain data of the vibration response obtained in step 1 during the start-up and shutdown periods are respectively subjected to f Hz bandpass filtering;
[0013] The impulse response spectrum of the bandpass filtered data is calculated and processed into an equivalent sine wave to obtain the equivalent sine wave data of the impulse response spectrum during the start-up and shutdown periods.
[0014] In the above-mentioned design method for longitudinal sinusoidal vibration test conditions of launch vehicle instruments and equipment, the value range of f is 2 to 100.
[0015] In the above-mentioned design method for longitudinal sinusoidal vibration test conditions of launch vehicle instruments and equipment, the constant Q = 10 when performing equivalent sinusoidal processing.
[0016] In the above-mentioned design method for longitudinal sinusoidal vibration test conditions of launch vehicle instruments and equipment, the scanning rate of the acceptance-level longitudinal sinusoidal vibration test is 4 oct / min.
[0017] In the above-mentioned design method for longitudinal sinusoidal vibration test conditions of launch vehicle instruments and equipment, the value range of T is 1.5 to 2.
[0018] In the above-mentioned design method for longitudinal sinusoidal vibration test conditions of launch vehicle instruments and equipment, the scanning rate of the evaluation stage longitudinal sinusoidal vibration test is 2 oct / min.
[0019] In the above-mentioned design method for longitudinal sinusoidal vibration test conditions of launch vehicle instruments and equipment, the longitudinal transmission characteristic attenuation coefficient includes: the attenuation coefficient λ1 from the first stage inter-stage section to the launch vehicle tail section, the attenuation coefficient λ2 from the first and second stage inter-stage section to the first stage inter-stage section, the attenuation coefficient λ3 from the second stage inter-stage section to the first and second stage inter-stage section, and the attenuation coefficient λ4 from the instrument compartment section to the second stage inter-stage section.
[0020] In the above-mentioned design method for longitudinal sinusoidal vibration test conditions of launch vehicle instruments and equipment, λ1=λ2=λ3=λ4=0.9.
[0021] In the above-mentioned design method for longitudinal sinusoidal vibration test conditions of launch vehicle instruments and equipment, the vibration response time-domain curves of the engine's normal level seat or the connection between the frame and the compartment are collected by vibration sensors arranged on the engine's normal level seat or the connection between the frame and the compartment.
[0022] The present invention has the following advantages:
[0023] This invention discloses a method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment. It can quickly provide longitudinal sinusoidal vibration test conditions for individual equipment in each section of a new rocket, solving the problem of the difficulty in designing longitudinal sinusoidal vibration conditions during the demonstration phase of a new rocket program. As a top-level design of environmental conditions for a model, it can be applied to model program demonstration and individual equipment development. Attached Figure Description
[0024] Figure 1 This is a flowchart illustrating the steps of a method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment according to an embodiment of the present invention.
[0025] Figure 2 This is a schematic diagram of the vibration response time domain curve at the constant level seat of an engine in an embodiment of the present invention;
[0026] Figure 3 This is a schematic diagram of the equivalent sinusoidal data of the impact response spectrum during the start-up period at the constant level seat of an engine in an embodiment of the present invention;
[0027] Figure 4 This is a schematic diagram of the equivalent sinusoidal data of the impact response spectrum during the shutdown period at the normal level seat of an engine in an embodiment of the present invention;
[0028] Figure 5 This is a schematic diagram of the longitudinal sinusoidal vibration test magnitude of an instrument on the tail section of a launch vehicle in an embodiment of the present invention. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.
[0030] Environmental prediction is a gradual approximation process. During the design phase, it relies on measured data and statistical patterns from past successful models, combined with the specific conditions of the new rocket, to conduct preliminary and rapid environmental design. The purpose of this invention is to provide a method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment. According to this method, longitudinal sinusoidal vibration test conditions for individual equipment in each section of the rocket can be quickly formulated.
[0031] like Figure 1 In this embodiment, the method for designing longitudinal sinusoidal vibration test conditions for the launch vehicle instruments and equipment includes:
[0032] Step 1: Obtain the time-domain vibration response curves of the engine's normal mounting base or the docking point between the engine frame and the compartment during ground testing.
[0033] In this embodiment, during engine ground testing, vibration sensors can be placed at locations such as the engine's horizontal strut mount or the junction between the engine frame and the engine compartment. A sampling rate higher than 5120Hz is required to obtain the vibration response time-domain curves at the corresponding locations. The vibration response time-domain curve at the engine's horizontal strut mount during ground testing is shown below. Figure 2 As shown.
[0034] Step 2: Preprocess the vibration response time-domain curve obtained in Step 1 to obtain the equivalent sinusoidal data of the impact response spectrum.
[0035] In this embodiment, the preprocessing process is as follows:
[0036] 21) Extract the time-domain data of the vibration response time-domain curve obtained in step 1 for the start-up and shutdown periods and perform f Hz bandpass filtering.
[0037] For example, it can be intercepted Figure 1 The vibration response time-domain curve shown contains a segment of time-domain data exhibiting clear start-up characteristics (0–3s), representing the start-up period. This 0–3s segment of time-domain data is then subjected to an fHz bandpass filter. Figure 2 The vibration response time-domain curve shown contains a segment of time-domain data exhibiting clear shutdown characteristics (time-domain data from 199 to 202 seconds), representing the shutdown period. This segment of time-domain data from 199 to 202 seconds was subjected to an fHz bandpass filter. The value of f ranges from 2 to 100.
[0038] 22) Perform impulse response spectrum calculation and equivalent sine processing on the bandpass filtered data to obtain the equivalent sine data of the impulse response spectrum during the start-up and shutdown periods.
[0039] When calculating the impulse response spectrum, the improved digital filtering method in Appendix K of "GJB 2238A-2004 Telemetry Data Processing" can be used. The equivalent sine processing involves dividing the calculated impulse response spectrum by a constant Q at each frequency point, resulting in equivalent sine data for the impulse response spectrum, as shown below. Figure 3 , Figure 4 As shown. Where Q = 10.
[0040] Step 3: Envelope the equivalent sinusoidal data of the impact response spectrum obtained in Step 2, and determine the envelope result as the acceptance level longitudinal sinusoidal vibration test level for instruments and equipment on the tail section of the launch vehicle.
[0041] In this embodiment, the equivalent sinusoidal data of the impact response spectrum during the startup and shutdown periods are enveloped, and considering a certain engineering margin, the resulting envelope is determined as the acceptance-level longitudinal sinusoidal vibration test magnitude for instruments and equipment on the tail section of the launch vehicle. Figure 5 As shown. Among them, the scanning rate of the acceptance-level longitudinal sinusoidal vibration test is 4 oct / min.
[0042] Preferably, the acceptance-level longitudinal sinusoidal vibration test conditions for instruments and equipment on the tail section of the launch vehicle are shown in Table 1 below:
[0043]
[0044] Table 1. Acceptance-level longitudinal sinusoidal vibration test conditions for instruments and equipment on the tail section.
[0045] Step 4: Based on the longitudinal transmission characteristics, and using the longitudinal sinusoidal vibration test magnitude of the instruments and equipment on the tail section of the launch vehicle determined in Step 3, combined with the attenuation coefficient of the longitudinal transmission characteristics, obtain the longitudinal sinusoidal vibration test magnitude of the instruments and equipment on other sections of the launch vehicle.
[0046] In this embodiment, the longitudinal transfer characteristic attenuation coefficient includes: the attenuation coefficient λ1 from the first stage inter-stage section to the tail section of the launch vehicle, the attenuation coefficient λ2 from the first and second stage inter-stage section to the first stage inter-stage section, the attenuation coefficient λ3 from the second stage inter-stage section to the first and second stage inter-stage section, and the attenuation coefficient λ4 from the instrument compartment section to the second stage inter-stage section.
[0047] Preferably, based on the longitudinal transmission characteristics, and based on the longitudinal sinusoidal vibration test magnitude of the instruments and equipment on the tail section of the launch vehicle determined in step 3, combined with the longitudinal transmission characteristic attenuation coefficient, the longitudinal sinusoidal vibration test magnitude of the instruments and equipment on other sections of the launch vehicle is obtained. Specifically, the longitudinal sinusoidal vibration test magnitude of the instruments and equipment on the tail section of the launch vehicle determined in step 3 is multiplied by the corresponding longitudinal transmission characteristic attenuation coefficient (λ1, λ2, λ3, λ4) to obtain the longitudinal sinusoidal vibration test magnitude of the instruments and equipment on other sections of the launch vehicle.
[0048] Preferably, λ1=λ2=λ3=λ4=0.9.
[0049] For example, based on Table 1, the acceptance-level longitudinal sinusoidal vibration test conditions for instruments and equipment on other sections of the launch vehicle are shown in Table 2 below:
[0050]
[0051] Table 2. Acceptance-level longitudinal sinusoidal vibration test conditions for instruments and equipment in other modules.
[0052] Step 5: Multiply the acceptance-level longitudinal sinusoidal vibration test magnitude of the instruments and equipment on the tail section of the launch vehicle determined in Step 3 and the acceptance-level longitudinal sinusoidal vibration test magnitude of the instruments and equipment on other sections of the launch vehicle obtained in Step 4 by the safety factor T, and use the results as the evaluation-level longitudinal sinusoidal vibration test magnitude.
[0053] In this embodiment, the value of T ranges from 1.5 to 2. For example, T = 1.5 is chosen, meaning that the acceptance-level test magnitudes in Tables 1 and 2 are multiplied by 1.5 to obtain the qualification-level test magnitude. The scanning rate for the qualification-level longitudinal sinusoidal vibration test is also specified as 2 oct / min. Thus, the qualification-level longitudinal sinusoidal vibration test conditions for instruments and equipment on other sections of the launch vehicle are obtained, as shown in Table 3.
[0054]
[0055] Table 3. Test conditions for longitudinal sinusoidal vibration of instruments and equipment on other modules at the qualification level.
[0056] In summary, this invention discloses a method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment. This method has been successfully applied to the development of a new generation of liquid and solid-liquid coupled rockets, ensuring the sufficiency and accuracy of longitudinal sinusoidal vibration test assessments for individual onboard equipment. The new generation of liquid and solid-liquid coupled flight tests were successfully completed, and the flight results demonstrate that the designed longitudinal sinusoidal vibration test can effectively reflect flight telemetry results. This invention's method has been applied to the development of subsequent models of the new generation of rockets.
[0057] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.
[0058] The contents not described in detail in this specification are common knowledge to those skilled in the art.
Claims
1. A method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment, characterized in that, include: Step 1: Obtain the vibration response time-domain curves at the engine's normal level seat or the junction between the engine frame and the compartment during the engine ground test. During the engine ground test, vibration sensors are placed at the engine's normal level seat or the junction between the engine frame and the compartment, and the vibration response time-domain curves at the corresponding locations are collected by the vibration sensors. Step 2: Preprocess the vibration response time-domain curve obtained in Step 1 to obtain equivalent sinusoidal data of the impact response spectrum; this includes: extracting time-domain data from the vibration response time-domain curve obtained in Step 1 for the start-up and shutdown periods respectively. f Hz bandpass filtering; the impulse response spectrum is calculated and equivalent sine processing is performed on the bandpass filtered data to obtain the equivalent sine data of the impulse response spectrum during the start-up and shutdown periods; Step 3: Envelope the equivalent sinusoidal data of the impact response spectrum obtained in Step 2, and determine the envelope result as the acceptance level longitudinal sinusoidal vibration test level for the instruments and equipment on the tail section of the launch vehicle; including: enveloping the equivalent sinusoidal data of the impact response spectrum during the start-up and shutdown periods, and considering a certain engineering margin, determining the envelope result as the acceptance level longitudinal sinusoidal vibration test level for the instruments and equipment on the tail section of the launch vehicle. Step 4: Based on the longitudinal transmission characteristics and the acceptance-level longitudinal sinusoidal vibration test magnitude of the instruments and equipment on the tail section of the launch vehicle determined in Step 3, and combined with the longitudinal transmission characteristic attenuation coefficient, obtain the acceptance-level longitudinal sinusoidal vibration test magnitude of the instruments and equipment on other sections of the launch vehicle; wherein, the longitudinal transmission characteristic attenuation coefficient includes: the attenuation coefficient λ1 from the first stage inter-company section to the tail section of the launch vehicle, the attenuation coefficient λ2 from the first and second stage inter-sections to the first stage inter-company section, the attenuation coefficient λ3 from the second stage inter-company section to the first and second stage inter-sections, and the attenuation coefficient λ4 from the instrument section to the second stage inter-company section; Step 5: Multiply the acceptance-level longitudinal sinusoidal vibration test magnitude of the instruments and equipment on the tail section of the launch vehicle determined in Step 3 and the acceptance-level longitudinal sinusoidal vibration test magnitude of the instruments and equipment on other sections of the launch vehicle obtained in Step 4 by the safety factor T to obtain the evaluation-level longitudinal sinusoidal vibration test magnitude.
2. The method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment according to claim 1, characterized in that, f The value range is 2 to 100.
3. The method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment according to claim 1, characterized in that, When performing the equivalent sine treatment, the constant Q = 10.
4. The method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment according to claim 1, characterized in that, The scanning rate for the acceptance-level longitudinal sinusoidal vibration test is 4 oct / min.
5. The method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment according to claim 1, characterized in that, The value of T ranges from 1.5 to 2.
6. The method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment according to claim 1, characterized in that, The scanning rate for the identification-grade longitudinal sinusoidal vibration test is 2 oct / min.
7. The method for designing longitudinal sinusoidal vibration test conditions for launch vehicle instruments and equipment according to claim 1, characterized in that, λ1=λ2=λ3=λ4=0.9.