Locking and releasing mechanism reliability evaluation method based on dynamics

Abstract

The invention provides a locking and releasing mechanism reliability evaluation method based on dynamics. The method comprises the steps that random modeling is conducted on the initial position of a stud in a locking and releasing mechanism; carrying out degradation characteristic modeling aiming at the piezoelectric coefficient degradation of the piezoelectric stack; the randomness of the stud and the degradation characteristic of the piezoelectric stack are introduced into a dynamic model of the locking and releasing mechanism; the responses of the mechanism under different conditions are analyzed through numerical simulation; defining a fault mode of the locking and releasing mechanism in combination with a simulation result; and evaluating the reliability of the locking and releasing mechanism by adopting a Kaplan-Meier survival analysis method. According to the invention, the precision and effectiveness of reliability evaluation are improved, the dynamic response of the locking and releasing mechanism under different working conditions is accurately evaluated, and the possible fault mode and failure probability of the mechanism after long-time operation are more accurately predicted; and the influence of the complex environment on the reliability of the system can be better simulated and evaluated, so that the stability and the safety in an actual task are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of aerospace equipment evaluation, and in particular to a dynamics-based locking and releasing mechanism reliability evaluation method. Background Art

[0002] In the gravitational wave detection mission, the design and implementation of the locking and release mechanism is crucial to ensure the precise release of the detector test mass on orbit. The design and reliability of this key component directly affects the success rate of the detection mission.

[0003] Currently, the locking and release of test masses are mainly achieved by mechanical or electrical means. For example, common methods include the use of piezoelectric stacks to achieve high-precision release. However, with the increasing complexity of the space environment, these existing locking and release mechanisms face many challenges in reliability evaluation in long-term use.

[0004] In current technology, the degradation characteristics of piezoelectric materials are a significant problem. Over time, the performance of the piezoelectric stack gradually degrades, resulting in reduced release accuracy, which directly affects the stability of the locking release mechanism. In addition, mechanical components, such as studs, may be affected by factors such as vibration and temperature fluctuations in the space environment, resulting in a shift in their initial position, which further affects the reliability of the release process.

[0005] To address these challenges, existing technical solutions often enhance the reliability of the mechanism by improving material quality or adding redundant design. However, these methods fail to fully consider the complex relationship between dynamic behavior and material degradation characteristics, making it difficult to effectively predict the long-term reliability of the system under extreme environments. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a dynamics-based locking and release mechanism reliability assessment method to solve the technical problem that the prior art cannot effectively predict the long-term reliability of the locking and release mechanism in a complex spatial environment. The present invention comprehensively considers the randomness and degradation characteristics of the mechanism, and provides a basis for the design and reliability improvement of the locking and release mechanism through dynamic modeling and simulation combined with the Kaplan-Meier survival analysis method.

[0007] The technical solution of the present invention is: a reliability evaluation method of a locking and releasing mechanism based on dynamics, comprising the following steps:

[0008] S1), stochastic modeling of the initial position of the stud in the locking and releasing mechanism;

[0009] S2), modeling the degradation characteristics of the piezoelectric coefficient degradation of the piezoelectric stack;

[0010] S3), introducing the randomness of the stud and the degradation characteristics of the piezoelectric stack into the dynamic model of the locking and releasing mechanism; analyzing the response of the mechanism under different conditions through numerical simulation;

[0011] S4), defining the failure mode of the locking and releasing mechanism in combination with the simulation results;

[0012] S5) The Kaplan-Meier survival analysis method was used to evaluate the reliability of the locking and releasing mechanism.

[0013] Preferably, in step S1), stochastic modeling is performed on the initial position of the stud in the locking and releasing mechanism, which specifically includes the following steps:

[0014] S11), determining the initial position of the stud, taking the gap D0 between the ejector pin and the test mass as a reference;

[0015] S12), based on the stress conditions of the studs in the actual flight environment, it is assumed that the position offset of the studs obeys a half-normal distribution;

[0016] S13), using Monte Carlo simulation to generate n initial position samples of studs, and calculate the resulting ejector offset D σj ;

[0017] S14), importing the generated stud displacement samples into the dynamic model to analyze their influence on the system amplitude and failure mode.

[0018] Preferably, in step S13), a Monte Carlo simulation is used to generate S initial position samples of studs, and the ejector offset D generated thereby is calculated. σj ; Specifically include the following steps:

[0019] S131), setting parameters, defining the z-axis coordinate of the standard position of the stud as 0; using Monte Carlo simulation to generate the position disturbance of the stud, assuming that the position disturbance obeys a half-normal distribution, and the standard deviation of the disturbance is 0.5 microns;

[0020] S132), generate samples, use the normrnd function in MATLAB to generate the initial position samples of S studs; the standard deviation is 0.5 microns, and the mean is 0;

[0021] S133), equivalent ejector pin offset, the generated initial position sample of the stud is equivalent to the offset caused by the ejector pin.

[0022] Preferably, in step S14), the dynamic model is a mass-spring-damper system model, and its expression is:

[0023]

[0024] Where m1, m2, and m3 represent the mass of the force sensor and the plunger, the mass of the spacer block and the two piezoelectric stacks, and the mass of the ejector pin, respectively; z1(t), z2(t), and z3(t) represent the displacements corresponding to the three degrees of freedom, respectively; They represent the velocities corresponding to the three degrees of freedom respectively; They represent the accelerations corresponding to the three degrees of freedom respectively; F p 、F TM are the force output by the piezoelectric stack and the preload force applied by the ejector pin to the test mass; c p,1 、c p,2 Respectively represent the damping of the upper and lower piezoelectric stacks; k f , k p , k d They represent the stiffness of the force sensor, piezoelectric stack, and disc spring respectively.

[0025] Preferably, in step S14), the generated stud displacement samples are introduced into the dynamic model to analyze their influence on the system amplitude and failure mode, which specifically includes the following steps:

[0026] S141), establishing a dynamic model, first defining the dynamic model of the system as a mass-spring-damper system model;

[0027] S142), using the initial position sample data of the stud generated in step S13) as input in the dynamic model;

[0028] S143), evaluate the system amplitude and failure mode, bring the data into MATLAB, analyze the system amplitude after the simulation is completed; and combine the preset failure mode to determine whether the system will fail under different offset conditions.

[0029] Preferably, in step S2), the degradation characteristic modeling is performed for the piezoelectric coefficient degradation of the piezoelectric stack, specifically comprising the following steps:

[0030] S21) Select piezoelectric material and measure its piezoelectric coefficient d 33 The changes under different cycle numbers,

[0031] Initial d 33 Set to normal value;

[0032] S22), the output displacement L of the piezoelectric stack and the piezoelectric coefficient d 33 The relational expression is:

[0033] L = n·d 33 V;

[0034] Where n is the number of piezoelectric ceramics, V is the input voltage;

[0035] S23) Based on the test data, establish 33 The model decays over time and sets the maximum operating voltage to 150V;

[0036] S24) Use Matlab to perform dynamic simulation and analyze the output displacement and system response of the piezoelectric stack under different degradation states; namely:

[0037]

[0038] Where m1, m2, and m3 represent the mass of the force sensor and the plunger, the mass of the spacer block and the two piezoelectric stacks, and the mass of the ejector pin, respectively; z1(t), z2(t), and z3(t) represent the displacements corresponding to the three degrees of freedom, respectively; They represent the velocities corresponding to the three degrees of freedom respectively; They represent the accelerations corresponding to the three degrees of freedom respectively; k1, k2, k3 represent the stiffness of the force sensor and the external connection, the stiffness of the piezoelectric stack, and the stiffness of the disc spring respectively; c represents the damping coefficient of the piezoelectric stack; F p 、F TM They are the force output by the piezoelectric stack and the preload applied by the ejector pin to the test mass.

[0039] Preferably, in step S3), the randomness of the stud and the degradation characteristics of the piezoelectric stack are introduced into the dynamic model of the locking and releasing mechanism; and the response of the mechanism under different conditions is analyzed by numerical simulation, which specifically includes the following steps:

[0040] S31), the initial position sample of the imported stud and the piezoelectric stack coefficient

[0041] The sample data of the initial position of the stud generated in step S13) is used as the input of the dynamic model, and the degradation characteristics of the piezoelectric stack are considered, which decays with the number of times of use, and the maximum amplitude of the output is obtained by substituting it into the dynamic model;

[0042] S32) Evaluate system amplitude and failure mode

[0043] After the simulation is completed, analyze the system response data, especially the system amplitude; draw a graph of the system amplitude changing with time or frequency to observe whether there is an abnormal increase in amplitude; and identify possible failure modes in combination with the preset failure modes.

[0044] Preferably, in step S4), the failure mode of the locking and releasing mechanism is defined in combination with the simulation results, which specifically includes the following steps:

[0045] S41), setting a failure threshold based on the plunger amplitude and the change in the gap between the plunger and the test mass;

[0046] S42), through multiple simulations, the maximum amplitude A and gap G of the system under different stud initial positions and piezoelectric stack degradation degrees are calculated;

[0047] S43), calculating the fault index α, and setting different failure criteria according to the fault index α, wherein the expression of the fault index α is:

[0048]

[0049] Where A0 and G0 represent the maximum amplitude of the plunger and the gap between the plunger and the test mass without considering randomness and degradation, respectively; A t , G t It represents the maximum amplitude of the plunger and the gap between the plunger and the test mass after t cycles, taking into account randomness and degradation characteristics.

[0050] Preferably, in step S5), the reliability of the locking and releasing mechanism is evaluated by using the Kaplan-Meier survival analysis method, which specifically includes the following steps:

[0051] S51), introducing the randomness of the stud and the degradation characteristics of the piezoelectric stack into the dynamic model at the same time, simulating the working state of the locking and releasing mechanism in the actual environment;

[0052] S52), performing simulation analysis on the initial position samples of the S studs, and looping N times, interpolating K time points, and recording the response data of the system;

[0053] S53), performing statistical analysis on the collected response data, evaluating the reliability of the locking and releasing mechanism, generating a survival curve of the system through Kaplan-Meier survival analysis, and determining its 95% confidence interval;

[0054] S54), applying the evaluation results to the design and optimization of the locking and releasing mechanism.

[0055] The beneficial effects of the present invention are:

[0056] 1. The present invention significantly improves the accuracy and effectiveness of evaluating the long-term reliability of complex mechanical systems. The present invention incorporates the randomness of the stud displacement and the degradation characteristics of the piezoelectric coefficient of the piezoelectric stack into the dynamic model, generates multiple samples through Monte Carlo simulation, and accurately evaluates the dynamic response of the locking and releasing mechanism under different working conditions. It can more accurately predict the possible failure modes and failure probabilities of the mechanism after long-term operation;

[0057] 2. The present invention uses the Kaplan-Meier survival analysis method to intuitively draw the survival curve of the locking and releasing mechanism, which helps analyze the reliability changes of the system during long-term operation; it is not only suitable for the design and optimization of the locking and releasing mechanism, but also can provide a basis for subsequent fault prediction and maintenance strategies;

[0058] 3. The method of the present invention can better simulate and evaluate the impact of these complex environments on system reliability by introducing randomness and degradation modeling, thereby ensuring the stability and safety of the locking and releasing mechanism in actual tasks. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a schematic diagram of the process of the present invention;

[0060] Figure 2 Graph showing system reliability results under different failure criteria according to an embodiment of the present invention. DETAILED DESCRIPTION

[0061] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0062] like Figure 1 As shown, this embodiment provides a method for evaluating the reliability of a locking and releasing mechanism based on dynamics, comprising the following steps:

[0063] S1), stochastic modeling of the initial position of the stud in the locking and releasing mechanism; specifically comprising the following steps:

[0064] S11), determining the initial position of the stud, taking the gap D0 between the ejector pin and the test mass as a reference, D0 in this embodiment is 4 μm;

[0065] S12), based on the stress conditions of the studs in the actual flight environment, it is assumed that the position offset of the studs obeys a half-normal distribution, and the standard deviation is set to 0.5 μm;

[0066] S13), using Monte Carlo simulation to generate 500 samples of the initial position of the studs, and calculate the resulting ejector offset D σj ; where j = 1, 2, ... 500;

[0067] S14), importing the generated stud initial position samples into the dynamic model to analyze their influence on the system amplitude and failure mode.

[0068] As a preferred embodiment of this embodiment, in step S13), 500 initial position samples of studs are generated by Monte Carlo simulation, and the ejector offset D generated thereby is calculated. σj ; Specifically include the following steps:

[0069] S131), setting parameters, defining the z-axis coordinate of the standard position of the stud as 0; using Monte Carlo simulation to generate the position disturbance of the stud, assuming that the position disturbance obeys a half-normal distribution, and the standard deviation of the disturbance is 0.5 microns;

[0070] S132), generating samples, using the normrnd function in MATLAB to generate 500 samples of the initial positions of the studs; the standard deviation is 0.5 microns, and the mean is 0;

[0071] S133), equivalent ejector pin offset, the generated initial position sample of the stud is equivalent to the offset caused by the ejector pin.

[0072] As a preferred embodiment of this invention, in step S14), the dynamic model is a mass-spring-damper system model, and its expression is:

[0073]

[0074] Where m1, m2, and m3 represent the mass of the force sensor and the plunger, the mass of the spacer block and the two piezoelectric stacks, and the mass of the ejector pin, respectively; z1(t), z2(t), and z3(t) represent the displacements corresponding to the three degrees of freedom, respectively; They represent the velocities corresponding to the three degrees of freedom respectively; They represent the accelerations corresponding to the three degrees of freedom respectively; F p 、F TM are the force output by the piezoelectric stack and the preload force applied by the ejector pin to the test mass; c p,1 、c p,2 Respectively represent the damping of the upper and lower piezoelectric stacks; k f , k p , k d They represent the stiffness of the force sensor, piezoelectric stack, and disc spring respectively.

[0075] As a preferred embodiment of this invention, in step S14), the generated stud displacement samples are introduced into the dynamic model to analyze their influence on the system amplitude and failure mode, which specifically includes the following steps:

[0076] S141), establishing a dynamic model, first defining the dynamic model of the system as a mass-spring-damper system model;

[0077] S142), using the initial position sample data of the stud generated in step S13) as input in the dynamic model;

[0078] S143), evaluate the system amplitude and failure mode, bring the data into MATLAB, analyze the system amplitude after the simulation is completed; and combine the preset failure mode to determine whether the system will fail under different offset conditions.

[0079] S2), modeling the degradation characteristics of the piezoelectric coefficient degradation of the piezoelectric stack; specifically comprising the following steps:

[0080] S21) Select a piezoelectric material, such as PZT ceramics, and measure its piezoelectric coefficient d 33 Changes under different cycle numbers, initial d 33 Set to normal value;

[0081] S22), the output displacement L of the piezoelectric stack and the piezoelectric coefficient d 33 The relational expression is:

[0082] L = n·d 33 V;

[0083] Wherein, n is the number of piezoelectric ceramics, V is the input voltage, and in this embodiment, V=120V;

[0084] S23) Based on the test data, establish 33 The model decays over time and sets the maximum operating voltage to 150V;

[0085] S24) Use Matlab to perform dynamic simulation and analyze the output displacement and system response of the piezoelectric stack under different degradation states; namely:

[0086]

[0087] Where m1, m2, and m3 represent the mass of the force sensor and the plunger, the mass of the spacer block and the two piezoelectric stacks, and the mass of the ejector pin, respectively; z1(t), z2(t), and z3(t) represent the displacements corresponding to the three degrees of freedom, respectively; They represent the velocities corresponding to the three degrees of freedom respectively; They represent the accelerations corresponding to the three degrees of freedom respectively; k1, k2, k3 represent the stiffness of the force sensor and the external connection, the stiffness of the piezoelectric stack, and the stiffness of the disc spring respectively; c represents the damping coefficient of the piezoelectric stack; F p 、F TM They are the force output by the piezoelectric stack and the preload applied by the ejector pin to the test mass.

[0088] S3), introducing the randomness of the stud and the degradation characteristics of the piezoelectric stack into the dynamic model of the locking and releasing mechanism; analyzing the response of the mechanism under different conditions through numerical simulation; specifically including the following steps:

[0089] S31), the initial position sample of the imported stud and the piezoelectric stack coefficient

[0090] The sample data of the initial position of the stud generated in step S13) is used as the input of the dynamic model, and the degradation characteristics of the piezoelectric stack are considered, which decays with the number of times of use, and the maximum amplitude of the output is obtained by substituting it into the dynamic model;

[0091] S32) Evaluate system amplitude and failure mode

[0092] After the simulation is completed, analyze the system response data, especially the system amplitude; draw a graph of the system amplitude changing with time or frequency to observe whether there is an abnormal increase in amplitude; and identify possible failure modes in combination with the preset failure modes.

[0093] S4), combining the simulation results, defining the failure mode of the locking release mechanism, specifically including the following steps:

[0094] S41), setting a failure threshold based on the plunger amplitude and the change in the gap between the plunger and the test mass;

[0095] S42), through multiple simulations, the maximum amplitude A and gap G of the system under different stud initial positions and piezoelectric stack degradation degrees are calculated;

[0096] S43), calculating the fault index α, and setting different failure criteria according to the fault index α, such as α>25%, α>20%, α>15%; wherein the expression of the fault index α is:

[0097]

[0098] Where A0 and G0 represent the maximum amplitude of the plunger and the gap between the plunger and the test mass without considering randomness and degradation, respectively; A t , G t It represents the maximum amplitude of the plunger and the gap between the plunger and the test mass after t cycles, taking into account randomness and degradation characteristics.

[0099] S5) The reliability of the locking and releasing mechanism is evaluated by using the Kaplan-Meier survival analysis method, which specifically includes the following steps:

[0100] S51), introducing the randomness of the stud and the degradation characteristics of the piezoelectric stack into the dynamic model at the same time, simulating the working state of the locking and releasing mechanism in the actual environment;

[0101] S52), simulate and analyze the initial position samples of 500 studs, and repeat for 10 times 7 times, interpolating 1000 time points and recording the system response data;

[0102] S53), performing statistical analysis on the collected response data, evaluating the reliability of the locking and releasing mechanism, generating a survival curve of the system through Kaplan-Meier survival analysis, and determining its 95% confidence interval;

[0103] S54), applying the evaluation results to the design and optimization of the locking and releasing mechanism.

[0104] like Figure 2 As shown, a large number of dynamic simulations and reliability analyses were performed in this embodiment. Taking into account the randomness of the stud displacement and the degradation characteristics of the piezoelectric stack, the failure mode identification of the system is more accurate. The Kaplan-Meier survival analysis results show that under different failure criteria, the survival rate of the locking release mechanism is significantly different. 7 After cycles, the system reliability under different failure criteria is 0.966, 0.902 and 0.710 respectively. The system reliability gradually decreases as the failure criteria are relaxed, which shows that the method of the present invention can effectively capture the degradation process of system performance over time.

[0105] The above embodiments and descriptions are only for illustrating the principles and best embodiments of the present invention. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and improvements, all of which fall within the scope of the present invention to be protected.

Claims

1. A reliability evaluation method for a locking and releasing mechanism based on dynamics, characterized in that: The steps include: S1), stochastic modeling of the initial position of the stud in the locking and releasing mechanism; S2), modeling the degradation characteristics of the piezoelectric coefficient degradation of the piezoelectric stack; S3), introducing the randomness of the stud and the degradation characteristics of the piezoelectric stack into the dynamic model of the locking and releasing mechanism; analyzing the response of the mechanism under different conditions through numerical simulation; S4), defining the failure mode of the locking and releasing mechanism in combination with the simulation results; S5) The Kaplan-Meier survival analysis method was used to evaluate the reliability of the locking and releasing mechanism.

2. The method for evaluating the reliability of a locking and releasing mechanism based on dynamics according to claim 1, characterized in that: In step S1), the initial position of the stud in the locking and releasing mechanism is randomly modeled, which specifically includes the following steps: S11), determining the initial position of the stud, taking the gap D0 between the ejector pin and the test mass as a reference; S12), based on the stress conditions of the studs in the actual flight environment, it is assumed that the position offset of the studs obeys a half-normal distribution; S13), using Monte Carlo simulation to generate n initial position samples of studs, and calculate the resulting ejector offset D σj ; S14), importing the generated initial position samples of the studs into the dynamic model to analyze their influence on the system amplitude and failure mode.

3. The method for evaluating the reliability of a locking and releasing mechanism based on dynamics according to claim 2, characterized in that: In step S13), the initial position samples of S studs are generated by Monte Carlo simulation, and the resulting ejector offset D is calculated. σj ; Specifically include the following steps: S131), setting parameters, defining the z-axis coordinate of the standard position of the stud as 0; using Monte Carlo simulation to generate the position disturbance of the stud, assuming that the position disturbance obeys a half-normal distribution, and the standard deviation of the disturbance is 0.5 microns; S132), generate samples, use the normrnd function in MATLAB to generate the initial position samples of S studs; the standard deviation is 0.5 microns, and the mean is 0; S133), equivalent ejector pin offset, the generated initial position sample of the stud is equivalent to the offset caused by the ejector pin.

4. The method for evaluating the reliability of a locking and releasing mechanism based on dynamics according to claim 2, characterized in that: In step S14), the dynamic model is a mass-spring-damper system model, and its expression is: Where m1, m2, and m3 represent the mass of the force sensor and the plunger, the mass of the spacer block and the two piezoelectric stacks, and the mass of the ejector pin, respectively; z1(t), z2(t), and z3(t) represent the displacements corresponding to the three degrees of freedom, respectively; They represent the velocities corresponding to the three degrees of freedom respectively; They represent the accelerations corresponding to the three degrees of freedom respectively; F p 、F TM are the force output by the piezoelectric stack and the preload force applied by the ejector pin to the test mass; c p,1 、c p,2 Respectively represent the damping of the upper and lower piezoelectric stacks; k f , k p , k d They represent the stiffness of the force sensor, piezoelectric stack, and disc spring respectively.

5. The method for evaluating the reliability of a locking and releasing mechanism based on dynamics according to claim 4, characterized in that: In step S14), the generated stud displacement samples are introduced into the dynamic model to analyze their influence on the system amplitude and failure mode, which specifically includes the following steps: S141), using the initial position sample data of the stud generated in step S13) as input in the dynamic model; S143), evaluate the system amplitude and failure mode, bring the data into MATLAB, analyze the system amplitude after the simulation is completed; and combine the preset failure mode to determine whether the system will fail under different offset conditions.

6. The method for evaluating the reliability of a locking and releasing mechanism based on dynamics according to claim 1, characterized in that: In step S2), degradation characteristic modeling is performed for the piezoelectric coefficient degradation of the piezoelectric stack, specifically including the following steps: S21) Select piezoelectric material and measure its piezoelectric coefficient d 33 Changes under different cycle numbers, initial d 33 Set to normal value; S22), the output displacement L of the piezoelectric stack and the piezoelectric coefficient d 33 The relational expression is: L=n·d 33 V; Where n is the number of piezoelectric ceramics, V is the input voltage; S23) Based on the test data, establish 33 The model decays over time and sets the maximum operating voltage to 150V; S24) Use Matlab to perform dynamic simulation and analyze the output displacement and system response of the piezoelectric stack under different degradation states; namely: Where m1, m2, and m3 represent the mass of the force sensor and the plunger, the mass of the spacer block and the two piezoelectric stacks, and the mass of the ejector pin, respectively; z1(t), z2(t), and z3(t) represent the displacements corresponding to the three degrees of freedom, respectively; They represent the velocities corresponding to the three degrees of freedom respectively; They represent the accelerations corresponding to the three degrees of freedom respectively; k1, k2, k3 represent the stiffness of the force sensor and the external connection, the stiffness of the piezoelectric stack, and the stiffness of the disc spring respectively; c represents the damping coefficient of the piezoelectric stack; F p 、F TM They are the force output by the piezoelectric stack and the preload applied by the ejector pin to the test mass.

7. The method for evaluating the reliability of a locking and releasing mechanism based on dynamics according to claim 1, characterized in that: In step S3), the randomness of the stud and the degradation characteristics of the piezoelectric stack are introduced into the dynamic model of the locking and releasing mechanism; the response of the mechanism under different conditions is analyzed by numerical simulation, which specifically includes the following steps: S31), the initial position sample of the imported stud and the piezoelectric stack coefficient The sample data of the initial position of the stud generated in step S13) is used as the input of the dynamic model, and the degradation characteristics of the piezoelectric stack are considered, which decays with the number of times of use, and the maximum amplitude of the output is obtained by substituting it into the dynamic model; S32) Evaluate system amplitude and failure mode After the simulation is completed, analyze the system response data, especially the system amplitude; draw a graph of the system amplitude changing with time or frequency to observe whether there is an abnormal increase in amplitude; and identify possible failure modes in combination with the preset failure modes.

8. The method for evaluating the reliability of a locking and releasing mechanism based on dynamics according to claim 1, characterized in that: In step S4), the failure mode of the locking and releasing mechanism is defined in combination with the simulation results, which specifically includes the following steps: S41), setting a failure threshold based on the plunger amplitude and the change in the gap between the plunger and the test mass; S42), through multiple simulations, the maximum amplitude A and gap G of the system under different stud initial positions and piezoelectric stack degradation degrees are calculated; S43), calculating the fault index α, and setting different failure criteria according to the fault index α, wherein the expression of the fault index α is: Where A0 and G0 represent the maximum amplitude of the plunger and the gap between the plunger and the test mass without considering randomness and degradation, respectively; A t , G t It represents the maximum amplitude of the plunger and the gap between the plunger and the test mass after t cycles, taking into account randomness and degradation characteristics.

9. The method for evaluating the reliability of a locking and releasing mechanism based on dynamics according to claim 1, characterized in that: In step S5), the reliability of the locking and releasing mechanism is evaluated by using the Kaplan-Meier survival analysis method, which specifically includes the following steps: S51), introducing the randomness of the stud and the degradation characteristics of the piezoelectric stack into the dynamic model at the same time, simulating the working state of the locking and releasing mechanism in the actual environment; S52), performing simulation analysis on the initial position samples of the S studs, and looping N times, interpolating K time points, and recording the response data of the system; S53), performing statistical analysis on the collected response data, evaluating the reliability of the locking and releasing mechanism, generating a survival curve of the system through Kaplan-Meier survival analysis, and determining its 95% confidence interval; S54), applying the evaluation results to the design and optimization of the locking and releasing mechanism.

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