A safety analysis and assessment method for thermal separation structures of guided missile skids

Abstract

The present invention discloses a safety analysis and assessment method for the thermal separation structure of a guided missile sled. Based on the characteristics of the rocket sled system, a finite element calculation method is used to construct a multi-stage coupling system model to solve the problems of the on-orbit motion response of the guided thermal separation structure and the stability of the separation process. The safety of the thermal separation structure of the rocket sled system is evaluated to provide support for the optimization of the new guide rail structure and the stability analysis of the rocket sled system. This method is used to evaluate the separation process of a rocket sled using a new guide rail structure. The parameters such as the size, shape, and mass of the test object are not controlled; the distance between the missile sled and the separation distance is adjustable; the separation speed is adjustable and controllable; and the separation environment is interference-free or low-interference, which facilitates the performance assessment of the test object.

Description

Technical Field

[0001] The present invention belongs to the technical field of shooting range testing, and in particular relates to a safety analysis and evaluation method for a thermal separation structure of a guided missile skid. Background Art

[0002] A rocket sled is a ground-based test device powered by a rocket engine and running along a slide. It can achieve the desired speed, acceleration, and other environmental conditions according to design requirements. Recoverable rocket sleds utilize a specially designed braking system to brake and recover the sled. Because of its ability to simulate flight conditions, rocket sleds have become a highly effective specialized testing method for modern ground-based testing equipment. Rocket sled testing primarily simulates the dynamic environment of flight to address numerous technical challenges associated with high speeds and accelerations in the development of aircraft, missiles, and aerospace vehicles.

[0003] Rocket sled testing technology is widely used in endpoint effects testing because it can realistically simulate the velocity and attitude of a test object at the endpoint of its trajectory at a 1:1 scale on the ground. Compared to live-fire flight testing, it is simpler to operate, less challenging, more repeatable, and less expensive. However, endpoint effects testing often requires the test object to function independently, requiring separation from the sled before impact with the target.

[0004] At present, there are still some shortcomings in the separation methods of rocket sled tests at home and abroad: (1) The separation process is not thorough, and there is a risk of affecting the penetration process of the test object; (2) Random disturbances cannot be accurately characterized, and the control accuracy of the target posture and position is insufficient; (3) As the test speed and load increase, the separation reliability is difficult to guarantee. Summary of the Invention

[0005] In order to overcome the deficiencies of the prior art, the present invention provides a safety analysis and assessment method for the thermal separation structure of a guided missile sled. Based on the characteristics of the rocket sled system, a finite element calculation method is used to construct a multi-stage coupling system model to solve the problems of the on-orbit motion response of the guided thermal separation structure and the stability of the separation process; the safety of the thermal separation structure of the rocket sled system is assessed, providing support for the optimization of the new guide rail structure and the stability analysis of the rocket sled system. This method is used to evaluate the separation process of a rocket sled using a new guide rail structure. The parameters such as the size, shape, and mass of the test object are not controlled; the distance between the missile sled and the separation distance is adjustable; the separation speed is adjustable and controllable; and the separation environment is interference-free or low-interference, which is convenient for the performance assessment of the test object.

[0006] The technical solutions adopted by the present invention to solve the technical problems are as follows:

[0007] Step 1: Establish the rocket sled-track two-stage coupling system structural model and finite element model;

[0008] The model is constructed based on the combination of rigid-flexible coupling dynamics, variable mass dynamics and orbital dynamics. The structural models of the rocket sled, test object components, wedge-shaped limit blocks, guide rails and tracks are established. The connection method between the test object components and the guide rails is simplified according to the actual motion conditions, and each component is assigned according to the actual material parameters.

[0009] Step 2: Complex excitation source analysis;

[0010] Based on the calculation results of the rocket sled's trajectory and the aerodynamic forces of the rocket sled system, the aerodynamic external loads, thrust loads, and track irregularity excitations on the rocket sled itself were analyzed. The constraint loads between the guide rail and the ring shoe of the test component, the changes in the engine thrust load when the test component separates from the rocket sled, and the changes in the aerodynamic load on the test component's head during the separation process of the test component from the sled were analyzed.

[0011] Step 3: Calculate and analyze the working conditions and boundary condition loading;

[0012] According to the test requirements, the key operating conditions of the rocket sled are analyzed, including the maximum speed moment of the rocket sled before separation and the separation process analysis. Under different operating conditions, the rocket sled thrust, rocket sled aerodynamic drag, rocket sled aerodynamic lift, track irregularity, test article aerodynamic load, test article thrust load and ring shoe and guide rail constraint load are applied;

[0013] Step 4: Set up contact;

[0014] The track is constrained laterally and vertically according to the position of the fasteners; a surface-to-surface contact is set between the rocket sled and the track; a fixed constraint is established at the connection point between the guide rail and the rocket sled; a pre-tightening constraint is established between the guide rail and the test object;

[0015] Step 5: Set the time step, calculation time and output the calculation file;

[0016] Determine the calculation step size based on the maximum speed of the rocket sled, track irregularity, and the free mode of the rocket sled; set the calculation time based on the movement speed and track length, and finally output the calculation file and perform the calculation;

[0017] Step 6: Analyze and evaluate the calculation results;

[0018] Output dynamic stress cloud diagrams of the rocket sled, test component, and guide rail under different working conditions, compare the material parameters of each component, and evaluate whether the structure is within the allowable stress range of the material;

[0019] Extract the displacement time history curves of the test object, ring shoe, guide rail, and sliding shoe, and analyze the system frequency response by combining the system excitation frequency and natural frequency; extract the acceleration time history curves of the test object, ring shoe, guide rail, and sliding shoe, and analyze the system vibration response;

[0020] Extract the displacement changes of the guide rail and the test object and compare them to evaluate whether the displacement of the guide rail affects the movement of the test object;

[0021] Extract the change in the separation distance between the test object and the sled to evaluate whether the requirements of the trajectory design are met;

[0022] Combined with the above data analysis, a comprehensive evaluation of the dynamic strength, frequency and vibration of the rocket sled system is conducted to assess the safety of the system;

[0023] Step 7: Test verification;

[0024] Carry out rocket sled tests and verify the system safety of the guided missile sled's thermal separation structure through test results.

[0025] Preferably, in step 1, a gap needs to be reserved between the guide rail and the ring shoe.

[0026] Preferably, in step 4, the sliding shoe and the track are set to be in surface contact; the ring shoe and the wedge-shaped limit block, the ring shoe and the guide rail, and the guide rail and the wedge-shaped limit block are all required to be in contact, among which the guide rail and the wedge block are set to be in point-to-surface contact, and the wedge block and the ring shoe, and the ring shoe and the guide rail are set to be in surface contact.

[0027] Preferably, in step 5, the time step dt should be set to meet the following conditions: assuming that the maximum speed in the rocket sled analysis is v max , the minimum track unevenness spacing is dl min , the sixth order of the rocket sled free mode is freq6, then:

[0028]

[0029] Preferably, in step 6, to obtain the displacement time-history curves of each component, it is necessary to analyze the response frequencies of the rocket sled, the test component and the rocket sled system, and analyze whether there is a resonance risk in the system and subsystem; the calculated response acceleration value of the test component needs to be compared with the sled that has been successfully tested at the same speed to analyze whether there is a risk of vibration amplification; for the calculated guide rail displacement time-history curve, during the time period when the ring shoe has not separated from the guide rail, if the displacement of the guide rail exceeds the gap between the guide rail and the ring shoe, it indicates that there is a risk of separation between the two under this working condition.

[0030] A computer program, which enables a computer to execute the above-mentioned security analysis and evaluation method.

[0031] An electronic device comprises: a processor and a memory; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the electronic device performs the above-mentioned security analysis and evaluation method.

[0032] A computer-readable storage medium stores a computer program, which implements the above-mentioned security analysis and evaluation method when executed by a processor.

[0033] A chip includes: a processor for calling and running a computer program from a memory, so that a device equipped with the chip executes the above-mentioned security analysis and evaluation method.

[0034] A computer program product includes a computer storage medium storing a computer program, wherein the computer program includes instructions executable by at least one processor, and when the instructions are executed by the at least one processor, the above-mentioned security analysis and evaluation method is implemented.

[0035] The beneficial effects of the present invention are as follows:

[0036] 1. For the first time, a dynamic response analysis method for missile-sled-rail coupling under multi-level coupling and complex aerodynamic mechanics environment was proposed, which realized the process control of the dynamic separation of the rocket sled test object on track under complex excitation and improved the accuracy of simulation analysis.

[0037] 2. This invention is the first to consider the safety analysis of the structure during the movement and separation of the test component in a multi-stage coupling system under the high dynamic environment of a rocket sled.

[0038] 3. The present invention analyzes and evaluates the safety of the thermal separation structure of the guided missile sled from multiple dimensions including material stress, vibration environment and response frequency, providing technical guarantee for the safe implementation of the rocket sled test. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a flowchart of the method of the present invention;

[0040] Figure 2 This is a schematic diagram of a structural model of a guided missile sled thermal separation rocket sled system according to an embodiment of the present invention;

[0041] Figure 3 The stress cloud diagrams of various components of the present invention are as follows: (a) stress cloud diagram of the skid, (b) stress cloud diagram of the test component, and (c) stress cloud diagram of the guide rail.

[0042] Figure 4 1 is a guide rail displacement diagram implemented in the present invention.

[0043] Figure 5 This is the displacement variation curve of the guide rail and the test piece implemented in the present invention.

[0044] Figure 6 This is the curve of the change in the separation distance between the test sample and the skid body in the implementation of the present invention.

[0045] Description of the accompanying drawings: 1—engine, 2—rocket sled body, 3—test component, 4—guide rail, 5—slide shoe. DETAILED DESCRIPTION

[0046] The present invention will be further described below with reference to the accompanying drawings and examples.

[0047] The purpose of the present invention is to address the on-orbit safety analysis of the thermal separation structure of a guided sled and propose a safety assessment method for the thermal separation structure of a guided sled. According to the characteristics of the rocket sled system, a finite element calculation method is used to construct a multi-stage coupling system model to solve the on-orbit motion response of the guided thermal separation structure and the stability of the separation process, evaluate the safety of the thermal separation structure of the rocket sled system, and provide support for the optimization of the new guide rail structure and the stability analysis of the rocket sled system. This method is used to evaluate the separation process of a rocket sled using a new guide rail structure, in which the parameters such as the size, shape, and mass of the test object are not controlled; the distance between the sleds is adjustable; the separation speed is adjustable and controllable; and the separation environment has no interference or low interference, which is convenient for the performance assessment of the test object.

[0048] The present invention is a safety assessment method for a guided missile skid thermal separation structure, comprising the following steps:

[0049] Step 1: Establish a structural model and finite element model of the rocket sled-track two-stage coupling system. During the modeling process, the model is constructed based on a combination of rigid-flexible coupling dynamics, variable mass dynamics, and track dynamics. Structural models of the rocket sled, test object assembly, wedge-shaped limit blocks, guide rails, and track are established. Based on actual motion conditions, the connection between the test object assembly and the guide rails is rationally simplified with a simplified constraint. Actual material parameters are assigned to each component.

[0050] Step 2: Complex excitation source analysis. Based on the calculation results of the rocket sled's trajectory and the aerodynamic forces of the rocket sled system, analyze the aerodynamic external loads, thrust loads, and track irregularity excitations acting on the rocket sled itself. Also required is analysis of the constraint loads between the guide rail and the test article assembly's ring shoe, the change in engine thrust load during separation of the test article assembly from the rocket sled, and the change in aerodynamic load on the test article's head during separation from the sled.

[0051] Step 3: Calculate and analyze operating conditions and boundary condition loading. Based on test requirements, analyze the rocket sled's critical operating conditions, including the moment of maximum speed before separation and the separation process. Apply rocket sled thrust, aerodynamic drag, aerodynamic lift, track irregularities, test article aerodynamic load, test article thrust load, and ring shoe and rail constraint loads under different operating conditions.

[0052] Step 4: Set up contact. Apply lateral and vertical constraints to the track based on the fastener positions; set up surface-to-surface contact between the rocket sled and the track; establish fixed constraints at the connection points between the guide rail and the rocket sled; and establish preloaded constraints between the guide rail and the test object.

[0053] Step 5: Set the step size, calculation time, and output the calculation file. Determine the calculation step size based on the maximum speed of the rocket sled, the track irregularity, and the rocket sled's free modes. Set the calculation time based on the speed and track length. Finally, output the calculation file and perform the calculation.

[0054] Step 6: Analysis and evaluation of calculation results. Output dynamic stress cloud maps of the rocket sled, test object components, and guide rails under different working conditions, compare the material parameters of each component, and evaluate whether the structure is within the allowable stress range of the material; extract the displacement time history curves of the test object, ring shoe, guide rail, and sliding shoe, and analyze the system frequency response by combining the system excitation frequency and natural frequency; extract the acceleration time history curves of the test object, ring shoe, guide rail, and sliding shoe to analyze the system vibration response; extract the displacement changes of the guide rail and test object and compare them to evaluate whether the displacement of the guide rail affects the movement of the test object; extract the change in the separation distance between the test object and the sled body to evaluate whether the requirements of the trajectory design are met; combined with the above data analysis, comprehensively evaluate the dynamic strength, frequency, and vibration of the rocket sled system to evaluate the safety of the system.

[0055] Step 7: Test Verification: Conduct rocket sled tests and verify the system safety of the guided missile sled's thermal separation structure through test results.

[0056] The present invention mainly focuses on the safety analysis and evaluation of the guided thermal separation structure under complex excitation.

[0057] In step 1, the model of the guide rail and the test object assembly is simplified. To ensure the smooth separation of the test object and the skid, a reserved gap between the guide rail and the ring shoe must be retained.

[0058] In step 4, the sliding shoe and the track are set to surface contact, the ring shoe and the wedge limit block, the ring shoe and the guide rail, and the guide rail and the wedge limit block must all be set to contact. Among them, the guide rail and the wedge block are set to point-to-surface contact, the wedge block and the ring shoe, and the ring shoe and the guide rail are set to surface contact. It is necessary to ensure that the contact between each component can reasonably represent the mutual contact relationship between the two.

[0059] The time step dt selected in step 5 should meet the following conditions. Assume that the maximum speed in the rocket sled analysis is v max , the minimum track unevenness spacing is dl min , the sixth order of the rocket sled free mode is freq6, then

[0060]

[0061] Step 6: To obtain the displacement time-history curves of each component, it is necessary to analyze the response frequencies of the rocket sled, the test component, and the rocket sled system, and analyze whether there is a resonance risk in the system and subsystem; the calculated response acceleration value of the test component needs to be compared with the sled that has been successfully tested at the same speed to analyze whether there is a risk of vibration amplification; for the calculated guide rail displacement time-history curve, if the displacement of the guide rail exceeds the gap between the guide rail and the ring shoe during the time period when the ring shoe has not separated from the guide rail, it indicates that there is a risk of separation between the two under this working condition.

[0062] In step 6, the obtained data is processed by RMS data. The filter frequency band that can retain most of the energy should be selected for analysis. Otherwise, the analyzed vibration data cannot guide the actual design.

[0063] Example:

[0064] The present invention is a safety assessment method for the thermal separation structure of a supersonic rocket sled guided missile sled. The method comprises the following steps: Figure 1 :

[0065] Step 1: Select any double-track rocket sled structure as the analysis object, and establish the structural model of the rocket sled-track system, the test component and the guide rail. The simplified rocket sled system model is as follows: Figure 2 shown.

[0066] Step 2: Complex excitation source analysis.

[0067] The boundary conditions for the calculation and analysis are as follows:

[0068] The dynamic response calculation model is a rocket sled

[0069] Speed ​​is about 500m / s;

[0070] The total mass of the rocket sled is 1500kg;

[0071] Rocket sled engine thrust: 10,000N; Test component power: 100,000N;

[0072] Aerodynamic resistance of test piece: 13500N; Aerodynamic resistance of rocket sled: 145000N;

[0073] Aerodynamic lift of test piece: 5730N; Aerodynamic lift of rocket sled: -29000N;

[0074] Wedge-shaped limit block preload: 800N;

[0075] Lateral and vertical overload disturbance speed 0.3m / s;

[0076] Step 3: Calculate and analyze the working conditions and boundary condition loading.

[0077] The analysis condition is set as the safety analysis and evaluation of the separation process of the guided sled thermal separation structure. The overall requirement is that the on-orbit movement is within 0.2s and the separation distance between the sled and the test object reaches 1.5m.

[0078] The boundary condition loads are applied according to the thrust, aerodynamic drag, and aerodynamic lift values ​​in step 2. The heading velocity and lateral and vertical overload disturbance velocities are applied to the skid, and the various components of the skid are loaded.

[0079] Step 4: Set up contact. Apply vertical and lateral constraints to the track surface; set up surface-to-surface contact between the rocket sled and the track; establish fixed constraints at the connection point between the guide rail and the rocket sled; establish surface-to-surface contact between the guide rail and the test piece's ring shoe; and establish preload contact between the guide rail and the wedge stopper, and between the wedge stopper and the test piece's ring shoe.

[0080] Step 5: Set the step size, calculation time, and output the calculation file. Based on the maximum speed of the rocket sled, track irregularities, and the rocket sled's free modes, the calculation step size is 1e-4. Based on the speed and track length, set the calculation time to 0.4s. Finally, output the calculation file and assign values ​​for the yield strength, tangent modulus, and elongation parameters in the calculation file based on the actual material selected. After modification, save the file and continue the calculation.

[0081] Step 6: Analysis of calculation results.

[0082] Output the dynamic stress cloud diagram of the rocket sled, test component, and guide rail. The sled body stress is less than 300MPa, the test component stress is less than 60MPa, and the guide rail stress is less than 350MPa. Figure 3 As shown in Figure 2, the dynamic stress of all materials is lower than the allowable stress range of the materials, and the structure is safe. The displacement time history curve of the guide rail is extracted, as shown in Figure 2. Figure 4 As shown in the figure, the guide rail vibration frequency is about 22Hz, which is inconsistent with its natural frequency of 55Hz and the track interference frequency of 38Hz, and will not resonate; the acceleration time history curves of the test piece, ring shoe, guide rail, and sliding shoe are extracted, and the root mean square vibration of each component is analyzed as shown in Table 1, which is equivalent to the vibration level of the double-track skid under the same speed conditions, and the structure is safe; the displacement changes of the guide rail and the test piece are extracted for comparison, as shown in Figure 6 As shown in the figure, the analysis shows that the vibration of the guide rail has no effect on the test object; the variation of the separation distance between the test object and the sled body is extracted, and it is known that the design separation requirements can be met; from the above analysis and evaluation, it can be seen that the guided sled thermal separation structure is safe in on-track movement and can meet the overall requirements.

[0083] Table 1 Vibration RMS overload of each component

[0084]

[0085] Step 8: Test Verification: Conduct relevant rocket sled tests to verify the safety of the guided missile sled's thermal separation structure.

Claims

1. A safety analysis and assessment method for a thermal separation structure of a guided missile skid, characterized in that: The steps include: Step 1: Establish the rocket sled-track two-stage coupling system structural model and finite element model; The model is constructed based on the combination of rigid-flexible coupling dynamics, variable mass dynamics and orbital dynamics. The structural models of the rocket sled, test object components, wedge-shaped limit blocks, guide rails and tracks are established. The connection method between the test object components and the guide rails is simplified according to the actual motion conditions, and each component is assigned according to the actual material parameters. Step 2: Complex excitation source analysis; Based on the calculation results of the rocket sled's trajectory and the aerodynamic forces of the rocket sled system, the aerodynamic external loads, thrust loads, and track irregularity excitations on the rocket sled itself were analyzed. The constraint loads between the guide rail and the ring shoe of the test component, the changes in the engine thrust load when the test component separates from the rocket sled, and the changes in the aerodynamic load on the test component's head during the separation process of the test component from the sled were analyzed. Step 3: Calculate and analyze the working conditions and boundary condition loading; According to the test requirements, the key operating conditions of the rocket sled are analyzed, including the maximum speed moment of the rocket sled before separation and the separation process analysis. Under different operating conditions, the rocket sled thrust, rocket sled aerodynamic drag, rocket sled aerodynamic lift, track irregularity, test article aerodynamic load, test article thrust load and ring shoe and guide rail constraint load are applied; Step 4: Set up contact; The track is constrained laterally and vertically according to the position of the fasteners; a surface-to-surface contact is set between the rocket sled and the track; a fixed constraint is established at the connection point between the guide rail and the rocket sled; a pre-tightening constraint is established between the guide rail and the test object; Step 5: Set the time step, calculation time and output the calculation file; Determine the calculation step size based on the maximum speed of the rocket sled, track irregularity, and the free mode of the rocket sled; set the calculation time based on the movement speed and track length, and finally output the calculation file and perform the calculation; Step 6: Analyze and evaluate the calculation results; Output dynamic stress cloud diagrams of the rocket sled, test component, and guide rail under different working conditions, compare the material parameters of each component, and evaluate whether the structure is within the allowable stress range of the material; Extract the displacement time history curves of the test object, ring shoe, guide rail, and sliding shoe, and analyze the system frequency response by combining the system excitation frequency and natural frequency; extract the acceleration time history curves of the test object, ring shoe, guide rail, and sliding shoe, and analyze the system vibration response; Extract the displacement changes of the guide rail and the test object and compare them to evaluate whether the displacement of the guide rail affects the movement of the test object; Extract the change in the separation distance between the test object and the sled to evaluate whether the requirements of the trajectory design are met; Combined with the above data analysis, a comprehensive evaluation of the dynamic strength, frequency and vibration of the rocket sled system is conducted to assess the safety of the system; Step 7: Test verification; Carry out rocket sled tests and verify the system safety of the guided missile sled's thermal separation structure through test results.

2. A safety analysis and assessment method for a thermal separation structure of a guided missile skid according to claim 1, characterized in that: In step 1, a gap needs to be reserved between the guide rail and the ring shoe.

3. The safety analysis and assessment method for the thermal separation structure of a guided missile skid according to claim 2, characterized in that: In step 4, the sliding shoe and the track are set to be in surface contact; the ring shoe and the wedge limit block, the ring shoe and the guide rail, and the guide rail and the wedge limit block all need to be set to contact, among which the guide rail and the wedge block are set to be in point-to-surface contact, and the wedge block and the ring shoe, and the ring shoe and the guide rail are set to be in surface contact.

4. A safety analysis and assessment method for a thermal separation structure of a guided missile skid according to claim 3, characterized in that: In step 5, the time step dt should be set to meet the following conditions: assuming the maximum speed in the rocket sled analysis is v max , the minimum track unevenness spacing is dl min , the sixth order of the rocket sled free mode is freq6, then:

5. The safety analysis and assessment method for the thermal separation structure of a guided missile skid according to claim 4 is characterized in that: In step 6, to obtain the displacement time-history curves of each component, it is necessary to analyze the response frequencies of the rocket sled, the test component and the rocket sled system, and analyze whether there is a resonance risk in the system and subsystem; the calculated response acceleration value of the test component needs to be compared with the sled that has been successfully tested at the same speed to analyze whether there is a risk of vibration amplification; for the calculated guide rail displacement time-history curve, if the displacement of the guide rail exceeds the gap between the guide rail and the ring shoe during the time period when the ring shoe has not separated from the guide rail, it indicates that there is a risk of separation between the two under this working condition.

6. A computer program, characterized in that The computer program enables a computer to execute the method according to any one of claims 1 to 5.

7. An electronic device, characterized in that: include: processor and memory; The memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory, so that the electronic device performs the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

9. A chip, characterized in that: include: A processor, configured to call and run a computer program from a memory, so that a device equipped with the chip executes the method according to any one of claims 1 to 5.

10. A computer program product, characterized in that The computer program product comprises a computer storage medium storing a computer program, wherein the computer program comprises instructions executable by at least one processor, and when the instructions are executed by the at least one processor, the method according to any one of claims 1 to 5 is implemented.

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