Evidence-theory-based Structural Reliability Analysis Methods

Uncertainty is common in our daily life.Similarly,uncertainties are also very common in practical engineering applications.Due to the uncertainty of equipment manufacturing,installation,working environment,material characteristics and load characteristics,engineering equipment produces greater vibration and even failure during work.Therefore,mechanical equipment can be used in work.Reliability design analysis is particularly important.In practical engineering problems,because of the limited cognitive level or the lack of sample points,if the traditional probabilistic reliability method is used to solve the reliability analysis of Engineering structures,it will bring great errors,which can not truly reflect the reliability of the structure.Evidence theory,as one of the engineering methods of dealing with the problem of uncertainty,is a kind of extension development of probability theory,the use of a more general framework description of uncertain information input variables and output responses of credibility.Due to the evidence theory can deal with incomplete information,information conflict and other situations,it is relatively simple and convenient to model in reliability analysis,hence it has a unique advantage in dealing with uncertainties,and is widely used in engineering problems.This paper studies the algorithm and application of evidence theory in reliability design,the main research contents are as follows:1.This paper presents a new second-order moment structure reliability analysis method based on evidence theory improvement.Considering the fact that the reliability analysis of traditional evidence theory is too optimistic and the credibility is too conservative,this paper constructs a "two-segment" function function,the approximate function function can approximate its real function effectively,thus the analysis of focus element is more objective,and its analysis results can meet the need of engineering practical problem.2.This paper presents a method of reliability analysis of evidence theory based on local approximation model technique.First of all,based on the radial basis function to construct approximate function of functions,used to solve the problem of "black box";Then,using partial encryption technology in the area of error to partial encryption sample points,on the premise of meet reliability index solution efficiency,synchronous improve the approximation3.accuracy of agent model;finally,the method is applied to a two-and four-dimensional numerical example and also applied to a beam under compressive stress and a gear meshing engineering example to verify that the numerical results show the effectiveness of this method.4.A reliability design software platform based on evidence theory is established based on Visual Basic 6,The platform simplifies the flow of parameter setting,improves the efficiency of reliability calculation,reduces the workload of reliability designers,shortens the cycle of product design,and has high economy.