Sructural Reliability Analysis Of Thin-Walled Box Girders Based On Stochastic Finite Element Method

This dissertation established numerical methods in the stochastic structural analysis on the basis of random fields theory, stochastic variational principle, Monte Carlo method and reliability theory, etc.. The numerical methods and the Monte Carlo method for thin-walled box girders are studied systematically. The one-dimensional stochastic finite element method for box-girders is proposed, and applied to the reliability analysis successfully. The main contributions of the thesis are as follows:1. Based on the local average theory of random fields, the computation formulas for discretized random fields is established. Combining the stochastic variational principle with the thin-walled box girders theory, the one-dimensional stochastic finite element method for thin-walled box girders is proposed.2. Based on the geometric meaning of the reliability index, the optimization method for the reliability computation is constructed, and the correlated abnormal distribution random fields are addressed. The one dimensional discretized stochastic finite element method is combined with the theory of thin-walled box girders, and the method for reliabilityanalysis of thin-walled box girders is established.3. Sampling methods for common distributing random numbers and the samples of random fields are proposed. Combining the Monte-Carlo simulation technique with the one-dimensional discretization finite element method, the Monte Carlo-finite element method for stochastic analysis and the reliability computation of thin-walled box girders are proposed in this thesis.