Approximate sensitivity analysis of structure system based on failure probability under epistemic and aleatory uncertainties

For analyzing effect of epistemic and aleatory uncertainties on failure probability of structure system involving uncertainties, two sensitivity indices, i.e. Correlation Coefficient and Correlation Ratio on the failure probability are defined, the universal method and approximate method for solving two indices are investigated and the corresponding precision and efficiency are discussed. By analyzing the two indices on the failure probability, the importance ranking of the uncertainty impacting on the failure probability can be quantified, on which the information for controlling the failure probability can be obtained effectively. After the detailing implementations for two sensitivity indices, several numerical and engineering samples are used to validate the precision and efficiency of two methods, and the law of the impact of the uncertainty parameters on the sensitivity result is obtained as well.