Dynamic Reliability Robust Optimal Design Of Vehicle Components

The reliability of automobile products depends on the reliability of the components,so it is very important to strengthen the research on the reliability of the components to improve the product quality of the independent brand automobile in China.In fact,due to the influence of the material properties and working environment,the reliability of the components is not always the same,but decreases gradually with the increase of time.In this paper,a dynamic reliability modeling method for vehicle components is proposed,and sensitivity analysis and robust optimization design are carried out.The specific contents are as follows:(1)In order to solve the dynamic reliability problem of components caused by random load and strength degradation,the load and strength are considered as stochastic processes,and the maximum equivalent load is obtained by using sequence statistics theory,the strength degradation process of parts is described by using Gamma process,and the dynamic reliability of parts is modeled.On this basis,the formula of dynamic reliability sensitivity of parts is given by using random perturbation theory and fourth-order moment technique,and the dynamic curves of the reliability of parts and the sensitivity of each parameter with time are obtained.The influence of the change of random variables on the reliability of parts is analyzed and verified by Monte Carlo method.(2)Considering the reliability problem of components in multiple failure modes,the correlation between each failure mode is analyzed by using Copula theory,and a dynamic reliability model is established for this.In this paper,taking gear as an example,the reliability problem in the case of two main failure modes is analyzed,and the dynamic curves of reliability varying with time are given.On the basis of the comparison with the gear reliability curve under the independent failure mode,the sensitivity analysis of the gear reliability in the case of failure mode is carried out.(3)In this paper,reliability theory and robust optimization theory are combined,reliability and reliability sensitivity of parts are considered as objective function or constraint condition of robust optimization,and three design schemes of reliability and robust optimization are put forward.The reliability and sensitivity curves of components under three optimization schemes are given,and the advantages and disadvantages of the three optimization schemes are compared.The correctness of the optimal scheme is verified by Monte Carlo method.The dynamic curve of the optimal size of the design variable under the optimal scheme is given,and the optimal size of the component at any time can be found quickly and accurately by the curve.(4)In this paper,the dynamic reliability and robust optimization design software of vehicle parts is designed and developed on the platform of MATLAB software and through the graphical interface GUI.The user only needs to input the relevant parameters according to the prompt of the interface,and then click the run button to get the calculation results.The development of the calculation software simplifies the operation steps and greatly improves the calculation efficiency.