Safety analysis and evaluation method suitable for guided missile-skid thermal separation structure

Abstract

The invention discloses a safety analysis and evaluation method suitable for a guided missile sled thermal separation structure, which is characterized in that according to the characteristics of a rocket sled system, a finite element calculation method is adopted to construct a multi-stage coupling system model, and the problems of in-orbit motion response and separation process stability of the guided thermal separation structure are solved; the safety of the thermal separation structure of the rocket sled system is evaluated, and support is provided for optimization of a novel guide sliding rail structure and stability analysis of the rocket sled system. When the method is used for evaluating the separation process of the rocket sled adopting the novel guide sliding rail structure, parameters such as the size, the appearance and the quality of a tested object are not controlled; the pulling distance of the elastic sledge is adjustable; the separation speed is adjustable and controllable; the separation environment is free of interference or low in interference, and performance examination of a tested object is facilitated.

Description

Technical Field

[0001] The 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 sled. Background Art

[0002] The rocket sled is a ground test equipment that uses a rocket engine as power and runs along a slide rail. The rocket sled can reach various environmental conditions such as the required speed and acceleration according to the design requirements. For the recovery type of rocket sled, a specially designed brake device is used to brake and recover the rocket sled. Since the rocket sled can simulate the main feature of the flight state, it has become a relatively effective special test method in the ground test equipment of modern equipment. The rocket sled test is mainly to simulate the dynamic environment during flight to solve many technical problems related to high speed and high acceleration in the development of aircraft, missiles, aerospace vehicles, etc.

[0003] Rocket sled test technology is widely used in terminal effect tests because it can realistically simulate the speed and posture of the test object at the end of the flight trajectory in a 1:1 state on the ground, and compared with live ammunition flight tests, it has the characteristics of simple operation, low test difficulty, repeatability, and low cost. However, terminal effect tests often require the test object to act alone, and the test object needs to be separated from the sled before colliding with the target.

[0004] At present, there are still some shortcomings in the rocket sled test sled separation methods 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 evaluation method for the thermal separation structure of a guided missile sled. According to the characteristics of the rocket sled system, a multi-stage coupling system model is constructed using the finite element calculation method 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, and the parameters such as the size, shape, and mass of the test product are not controlled; the distance the missile sled is pulled apart is adjustable; the separation speed is adjustable and controllable; the separation environment is interference-free or low-interference, which is convenient for the performance assessment of the test product.

[0006] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0007] Step 1: Establish the rocket sled-track two-stage coupling system structure 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 component, wedge-shaped limit block, guide rail and track are established. The connection mode between the test component and the guide rail is simplified according to the actual motion situation, and each component is assigned according to the actual material parameters.

[0009] Step 2: Complex excitation source analysis;

[0010] According to the calculation results of the rocket sled's trajectory and the aerodynamic force of the rocket sled system, the aerodynamic external load, thrust load, and track irregularity excitation on the rocket sled itself are analyzed; the constraint load between the guide rail and the ring shoe of the test component, the change of the engine thrust load when the test component is separated from the rocket sled, and the change of the aerodynamic load on the head of the test object during the separation of the test object from the sled body are 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. 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 under different working conditions.

[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 constraint with preload 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 length according to the maximum speed of the rocket sled, the track irregularity and the free mode of the rocket sled; set the calculation time according to 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 the 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 for comparison, and 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, the dynamic strength, frequency and vibration of the rocket sled system are comprehensively evaluated 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 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 arranged to be in surface-to-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 arranged to be in contact, wherein the guide rail and the wedge block are arranged to be in point-to-surface contact, and the wedge block and the ring shoe, and the ring shoe and the guide rail are arranged to be in surface-to-surface contact.

[0027] Preferably, in step 5, the setting of the time step dt should satisfy 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, and 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, wherein the computer program 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, which is used to call and run 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, comprising a computer storage medium storing a computer program, wherein the computer program comprises instructions executable by at least one processor, and the above-mentioned security analysis and evaluation method is implemented when the instructions are executed by the at least one processor.

[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 environment was proposed, which realized the process control of dynamic separation of rocket sled test specimens on track under complex excitation and improved the accuracy of simulation analysis.

[0037] 2. The present invention is the first to consider the safety analysis of the structure during the movement and separation of the test component of the multi-stage coupling system in the high dynamic environment of the 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, thus providing technical guarantee for the safe implementation of rocket sled tests. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0040] Figure 2 Schematic diagram of the structural model of a guided 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 body, (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 for implementing the present invention.

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

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

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

[0046] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[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 multi-stage coupling system model is constructed using the finite element calculation method 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, and the parameters such as the size, shape, and mass of the test product are not controlled; the distance the sled is pulled apart is adjustable; the separation speed is adjustable and controllable; the separation environment is interference-free or low-interference, which is convenient for the performance assessment of the test product.

[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 the rocket sled-track two-stage coupling system structural model and finite element model. In the modeling process, the model is constructed based on the rigid-flexible coupling dynamics, variable mass dynamics and track dynamics. The structural models of the rocket sled, test component, wedge-shaped limit block, guide rail and track are established, and the connection method between the test component and the guide rail is reasonably simplified according to the actual motion situation. Assign values ​​to each component according to the actual material parameters.

[0050] Step 2: Analysis of complex excitation sources. According to the calculation results of the rocket sled's trajectory and the aerodynamic force of the rocket sled system, the aerodynamic external load, thrust load, and track irregularity excitation of the rocket sled itself are analyzed. It is also necessary to analyze the constraint load between the guide rail and the ring shoe of the test component, the change of the engine thrust load when the test component is separated from the rocket sled, and the change of the aerodynamic load on the head of the test object during the separation of the test object from the sled body.

[0051] Step 3: Calculate and analyze the working conditions and boundary condition loading. According to the test requirements, carry out the analysis of the key working conditions of the rocket sled, including the maximum speed moment of the rocket sled before separation, the separation process analysis, and apply the rocket sled thrust, rocket sled aerodynamic drag, rocket sled aerodynamic lift, track unevenness, test article aerodynamic load, test article thrust load and ring shoe and guide rail constraint load under different working conditions.

[0052] Step 4: Set contact. Apply lateral and vertical constraints to the track according to the position of the fasteners; 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; and establish constraints with preload 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 roughness 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.

[0054] Step 6: Analysis and evaluation of calculation results. Output the 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 product, ring shoe, guide rail, and slide shoe, and analyze the system frequency response in combination with the system excitation frequency and natural frequency; extract the acceleration time history curves of the test product, ring shoe, guide rail, and slide shoe, and analyze the system vibration response; extract the displacement changes of the guide rail and the test product for comparison, and evaluate whether the displacement of the guide rail affects the movement of the test product; extract the change in the separation distance between the test product and the sled body, and evaluate whether the requirements of the trajectory design are met; combined with the above data analysis, comprehensively evaluate the dynamic strength, frequency and vibration analysis of the rocket sled system, and 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 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 effects.

[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 sled, 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 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 set to contact, among which the guide rail and the wedge block are set to be in point-to-surface contact, the wedge block and the ring shoe, and the ring shoe and the guide rail are set to be in surface contact, to ensure that the contact between each component can reasonably represent the mutual contact relationship between the two.

[0059] The selection of the time step dt 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, 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 means that there is a risk of separation between the two under this working condition.

[0062] In step 6, the obtained data is subjected to RMS data processing, and a 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 a certain supersonic rocket sled guided missile sled thermal separation structure. 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 ​​about 500m / s;

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

[0071] Rocket sled engine thrust: 10000N; Test component power: 100000N;

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

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

[0074] Wedge 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 loaded according to the thrust, aerodynamic drag and aerodynamic lift values ​​in step 2, and the heading speed and lateral and vertical overload disturbance speeds are applied to the sled to load the various components of the sled.

[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 between the guide rail and the rocket sled connection point; establish surface-to-surface contact between the guide rail and the test piece ring shoe; and establish preload force contact between the guide rail and the wedge-shaped limit block, and between the wedge-shaped limit block and the test piece ring shoe.

[0080] Step 5: Set the step size, calculation time and output the calculation file. According to the maximum speed of the rocket sled, the track roughness and the free mode of the rocket sled, the calculation step size is 1e-4; according to the movement speed and track length, the calculation time is set to 0.4s, and finally the calculation file is output and the yield strength, tangent modulus and elongation parameters of the material in the calculation file are assigned according to the actual selected materials. After modification, save the file and perform the calculation.

[0081] Step 6: Analyze the calculation results.

[0082] The dynamic stress cloud diagrams of the rocket sled, test component, and guide rail are output. 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 vibration frequency of the guide rail 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, 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 is extracted, and it can be seen 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 orbit and can meet the overall requirements.

[0083] Table 1 Vibration RMS overload of each component

[0084]

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

Claims

1. A safety analysis and evaluation method for the thermal separation structure of a guided missile sled, characterized in that: The steps include: Step 1: Establish the rocket sled-track two-stage coupling system structure 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 component, wedge-shaped limit block, guide rail and track are established. The connection mode between the test component and the guide rail is simplified according to the actual motion situation, and each component is assigned according to the actual material parameters. Step 2: Complex excitation source analysis; According to the calculation results of the rocket sled's trajectory and the aerodynamic force of the rocket sled system, the aerodynamic external load, thrust load, and track irregularity excitation on the rocket sled itself are analyzed; the constraint load between the guide rail and the ring shoe of the test component, the change of the engine thrust load when the test component is separated from the rocket sled, and the change of the aerodynamic load on the head of the test object during the separation of the test object from the sled body are 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. 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 under different working conditions. 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 constraint with preload 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 length according to the maximum speed of the rocket sled, the track irregularity and the free mode of the rocket sled; set the calculation time according to 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 the 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 for comparison, and 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, the dynamic strength, frequency and vibration of the rocket sled system are comprehensively evaluated to assess the safety of the system; Step 7: Test verification; Carry out rocket sled tests and verify the system safety of the guided 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. A safety analysis and evaluation method for a 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-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.

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 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:

5. A safety analysis and evaluation method for a thermal separation structure of a guided missile sled according to claim 4, 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, and 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 means 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 executes the method as claimed in 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 a method as claimed in 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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