Evaluation Of Durability Degradation For Dynamic Elastic Modulus And Section Stiffness Of Concrete Beams Based On The Wiener Process

It is one of the new directions at present that the reliability analysis and prediction of durability degradation process of concrete structures based on stochastic process.This paper is based on the wiener process to study the reliability of concrete structures durability degradation including the durability degradation process identification of concrete structure based on wiener process.residual life prediction and reliability assessment considering durability degradation.The main contents and findings of this paper are as follows:(1)Based on the current wiener process identification methods,that is the autocorrelation function method.The probabilistic and statistical verification methods is given for identification of wiener processes,which combined with the definition and related properties of wiener process.The autocorrelation function method is an approximate method to judge whether wiener process can be used to describe it or not,which compares the autocorrelation function graph of the wiener process with the durability degradation of a concrete structure.However,probability statistical verification is to judge it by verifying whether the definition of wiener process is satisfied or not.(2)According to the degradation process and damage mechanism of the dynamic elastic modulus of concrete beams and the flexural stiffness of concrete main beam section.The autocoi-relation function method and the probability statistical verification method are used to identify the degradation process of dynamic elastic modulus of concrete and the degradation process of flexural stiffness of main beam whether to meet wiener process.The results show that both can be modeled by wiener process.(3)The probability density function and the probability distribution function of wiener process and wiener process with drift are derived in this paper,and then the probability distribution function and the probability density function of the residual life as well as the curve of reliability degradation for them are given.