The Reliability Modeling Method Of Multiple-Site Damage Parts And Developing Corresponding Software

For the most MSD(Multiple-Site Damage) of parts in the engineering, they work in the same random load environment, so their failures are not independent generally, and the load dispersion leads to dependent failure of MSD parts. If the dependence of system failure is ignored, the analysis and calculation often lead an excessive error, sometimes even come to a wrong conclusion. The impact on parts reliability caused by dependent failure should be considered in the modeling of the MSD parts reliability.The paper proposes the method of normalizing load used in the reliability interference model based on the principle of sampling random variables on condition that the stress and strength of all the sites of the parts are both subjected to the Weibull distribution. Static parts reliability model is developed based on the principle of normalizing load.The time-dependent parts reliability model is developed base on the static parts reliability model with two factors namely the load frequency and strength degradation being considered. The research ideas are as follows:(1) The impact on parts reliability caused by the load frequency is merely considered. The time-dependent reliability model of the parts on the condition that random load acts for many times and the strength doesn’t degenerate or doesn’t degenerate obviously can be deduced based on the static model.(2) The impact caused by the load frequency and strength degeneration are both considered. The reliability when load acts for n times is equal to the probability of system being reliable as the nth time load acts on the parts. Time-dependent parts reliability model can be deduced with the factors the load frequency and strength degradation being considered.All the models are validated using Monte Carlo method.In this paper, the porous plate component as an example, building a finite element model of component, then analyzing the porous plate component by the finite element.The corresponding applied software which can be used to analyze the reliability of MSD parts is developed by matlab GUI.