Research And Application Of General Reliability Calculation Method In High Precision

The competitiveness of mechanical products is affected by their reliability directly,and high reliability is also the important character of current mechanical products.In order to analyze the reliability of products,effective reliability calculation methods are required.Although many of the existing reliability calculation methods in structural reliability analysis have been widely used,most of the methods are still facing the defects of lacking accuracy.Moreover,it is difficult to determine the degree of the calculation precision.In order to solve the problem of the precision of reliability calculation,a new reliability calculation method is proposed in the paper.The following researches are carried out in this paper:1.Based on reliability theory and the existing reliability calculation methods,a general reliability calculation method with high precision is proposed.A number of disjoint sub-sample spaces are obtained by dividing the sample space,then,a number of disjoint sub-failure domains are obtained by the intersection of sub-sample spaces and failure domain.By introducing the random variable,the probability of the sub-failure domain is obtained through the calculation of the sub-sample space probability and the conditional probability.Then,the probability of entire failure domain is obtained by adding the probabilities of sub-failure domains.In order to meet the requirements of the given calculation precision,the error control method is put forward.2.The accuracy of the method to calculate the failure probability of structure is verified.Based on the relationship between the standard normal distribution integral and the reliability calculation of the linear performance function,a method for computing the univariate standard normal distribution integral and bivariate standard normal distribution integral are put forward by calculating the failure probability of single failure mode linear performance function and the joint failure probability of two failure modes linear performance functions.Examples are given,the accuracy of the values of standard normal distribution integral which computed by using the proposed method are verified,therefore,the high precision results can be obtained when calculating the failure probability by using the proposed method in this paper.3.The proposed method is applied to the reliability calculation of examples of mechanical parts.Reliability calculation formulae are given by taking the bolt and shaft as examples.Results show that the method can satisfy the given precision when computing reliability of examples of mechanical parts,which has practical significance.