Sensitivity analysis of reliability for bar-plate structural systems

The optimization design of structural systems reliability based on Stochastic Finite Element Method (SFEM) is more reasonable than that based on the assured finite element method. The structural systems reliability analysis based on the assured finite element method is difficult to deal with the randomicity of structural parameters, for example, the material elastic modulus, the structural geometrical parameter. But SFEM is better to deal with various randomicity of structural system. The optimum design using sensitivity information is more efficient. At the same time, it is more difficult to put up the sensitivity analysis for the structural systems in the process of the optimum design of the structural system reliability, which is too complex. But the sensitivity analysis of structural systems is the key to the process of the structural optimum design. As the analysis object of Bar-plate structures, the sensitivity of structural system reliability is analysed using SFEM. The parsed expression for the sensitivity of structural systems reliability is showed, when the PNET method is used to calculate the structural systems reliability. The method greatly improved the sensitivity analysis precision and the optimum efficiency. The minimum weight optimum design obligated to reliability is progressed, using the optimum vector method. From the result, the correctness and validity of sensitivity analysis is proved.