Abstract: For the implicit reliability problem with multiple dimensions, the reliability sensitivity of structure is analyzed by applying the dimensionality reduction and visualization technique. The design point is found based on iHLRF method, and the step size of finite difference is determined according to the modeling computational precision. The plane is divided into two parts of safe domain and failure domain by a straight line, and the final position of the straight line is determined by calculating the responses corresponding to several data points nearby its initial position. The dimensionality and nonlinearity do not affect the accuracy of the proposed method, which also has relatively high efficiency. Finally, the reliabilities of two structural systems and the reliability sensitivities of various influencing factors are calculated, which provides a theoretical basis for designing the structural systems. The examples show that these theories and formulas are rational and efficient.

Key words: applied statistical mathematics, structural reliability, reliability sensitivity, design point, dimensionality reduction and visualization technique, iHLRF method