Active Control of Structures and Reliability Analysis by Subset Simulation Method

Abstract: Uncertainty is inherent in the control of all engineering structures. This uncertainty can arise from control hardware malfunctions, neglected system dynamics and other inadequacies of the mathematical model, errors in identifying parameters, model reduction, degradation of the structure over time, etc. If the uncertainties are not properly considered in the design of a control strategy, the performance of the controlled structure may be severely degraded, and an otherwise stable nominal structure may even become unstable due to actuator control forces. While the modeling assumptions have become more elaborate and accurate over the years, the reliability analysis of stochastic structural systems still remains a challenging problem. Therefore the reliability analysis of uncertain structural systems subjected to dynamic loads is of great engineering interest and poses a challenging computational problem. Because of the uncertainty inherent in engineering structures, consistent probabilistic stability/performance measures are essential to accurately assessing and comparing the robustness of structural control systems. Several reliability estimation methods, procedures and algorithms with various capabilities, accuracy and efficiency have been suggested in the past. A quantitative comparison of these approaches is considered t