Load Trans-path Model Of Structural Systems For Reliability Analysis

To ensure proper performance of engineering structures under given supporting loads and bearing environment during design lifetime, it is essential to give a reliability analysis. Therefore, the in-depth study of structural system reliability analysis methods is important. In order to rationalize the structural reliability analysis, the description of design variables and the reliability anlysis method of structural system were researched in this paper.First, the description and the sources of design variables, as well as the relative problems have been researched. By using confidence interval statistic theory, a stress-strength interference model based on parameter estimation interval was proposed. In this model, the statistical uncertainty of design variables was taken into account and the relationship between statistical uncertainty and sample size was determined. The model uncertainty was described by introducing a random variable. Because of the deviation between ideal distribution and real distribution of random variables, the robust estimation was introduced to estimate the parameters of distribution function.Hence the reliability analysis results are more credible and robust.Second, the studies of stochastic, fuzzy and non-probablistic models were dicussed in detail. By transforming the membership function into a similar probablilty density function and using the interval reliability measure, a unified hybrid reliability model was proposed.Last, a new method was proposed to obtain the structural internal force, which is more convenient than displacement finite element method and force finite element method. By using energy principle the algorithm of obtaining main load trans-paths was given. The members in a load trans-path are in series, so the reliability analysis method of a load tans-path model was developed. Then the structural system reliability analysis model was set up. By using this model the most important part of a structural system can be separated efficiently. The load trans-path model proposed in this paper is credible and safety.