Structural Reliability Analysis Based On Particle Filter

From the time of putting into use,the structure is faced with a seriers of problems such as the long-term effects of external loads,the erosion of the environment and the aging of buildig materials.The realiability of stuctures,therefore,sholud be particularly important to be ensured.Failure probability is one of the evaluation standards of structural reliability.In recent years,its calculation method has become a research focus of many scholars.However,many methods are extremely dependent on the structural ultimate bearing capacity equation,which is not suitable for complex structure.So the numerical simulation method is also developed.This article is based on the particle filter algorithm,the structural reliability analysis is divided into the following two aspects:Firstly,as far as the structure itself is concerned,its performance parameters will be uncertain due to the influence of many factors,which will have a certain impact on the reliability of the structure.In order to realize the reliability analysis of the structure considering the uncertainty of the structural parameters,this paper proposes a method of generating the probability density function of the structural parameters using the particle filter algorithm.After obtaining the knowledge of the structural parameter probability,the structural failure probability is calculated according to the corresponding specification,then the structural reliability is achieved.Secondly,as far as the external loads on the structure are concerned,seismic action is the most common,and also has a non-negligible impact on the reliability of the structure.The earthquake action has irremovable uncertainties.Therefore,this paper focuses on the uncertainty of seismic action and analyzes the reliability of the structure.Once the structure is put into use,its performance parameters will change with the accumulation of external loads and usage time.For these existing building structures,it is necessary to firstly determine the true value of its performance parameters when analyzing the reliability.This paper proposes a particle filter algorithm to identify the true values of the parameters of the existing building structure before the reliability analysis.At the same time,it proposes an adaptive particle filter for the structural structure mutation.Then the computational model is constructed based on the true values of the structural parameters identified by the particle filter algorithm,and the Monte Carlo algorithm is used to analyze the structural reliability considering the uncertainty of earthquake motions.Since the data of real seismic waves are relatively scarce,by studying the characteristics of the phase spectrum of real earthquake motions,a modified fractional Brownian motion model was used to simulate earthquake motions.Then enough seismic wave data for reliability analysis can be obtained.The reliability analysis method based on particle filter proposed in this paper can analyze the structural reliability from the two dimensions of the structural parameters and the external seismic load,and quantitatively analyze the effect of these two factors on the structural reliability.This reliability analysis method provides new ideas and also conducive to the scientific management of existing building structures.