The Strategy Of Imperfect Maintenance Replacement Based On Shock Model

Shock model is one of the most important topics in reliability theory,which is used to describe the process of system degradation under random environment.For shock models,it is of practical significance to study their theoretical indicators and maintenance strategies.Based on censored ? shock model,cumulative shock model and mixed model,this paper discusses the problem of maintenance strategy modeling.In the first model,a new censored 8 shock model is proposed based on traditional cen-sored ? shock model,which takes into account that the change of the failure threshold value and the maintenance time caused by the deterioration of the system and extends the failure state.Taking the minimum cost as the goal and the steady-state availability as the constraint condition,a model of imperfect replacement strategy for replacement strategy N is estab-lished,and three kinds of common lifetime expectation of shock arrival interval distribution are given.Finally,the validity of the model is verified by an example,and the sensitivity analysis of the parameters is carried out.In the second model,in order to study the average expected maintenance cost modeling problem of system with type ?,? failures,on the basis of the cumulative shock between two-unit systems,an analytical model has been established,which considering the increase of the failure rate of the components caused by the external shock of the system and using age-based maintenance and opportunity maintenance strategy.The existence condition of optimal opportunistic maintenance policy is determined with the objective of the lowest ex-pected maintenance cost.Finally,the validity of the model is verified by an example,and the sensitivity analysis is done to the parameters.In the third model,the reliability maintenance strategy of systems with self-healing function is studied based on cumulative shock,censored ? shock and ? shock.Considering the limited self-healing ability of the system,it is assumed that the system has three states:normal state of self-healing function,failure state of self-healing function and failure state of system.Aiming at the system with self-healing function,the finite Markov chain imbedding method is used to solve the relevant parameters,and two maintenance strategies and corre-sponding calculation formulas are proposed based on the number of shock number and the running time.Finally,a numerical example is used to verify the validity of the model.