An Efficient Approach for System Reliability-based Design Optimization

The reliability-based design optimization (RBDO) aims to design structures which should be reliable and economical. The RBDO involves the evaluation of probabilistic constraints, which can be done in two different ways : the reliability index approach (RIA), which describes the probabilistic constraint in terms of reliability index, and the performance measure approach (PMA) where the probability measure is converted to performance measure. It has reported in the literature that PMA approach is more efficient and more stable than RIA approach. However, the system reliability should be considered in the RBDO formulation. Traditionally the system reliability-based design optimization (SRBDO) is based on the reliability index approach (RIA), the system reliability analysis is included implicitly or explicitly in the probabilistic constraints. Nevertheless, the RBDO using the performance measure approach (PMA) does not formulated to take into account the system reliability requirement. In this paper an efficient SRBDO methodology is proposed to consider the system reliability requirement in the RBDO using PMA formulation, where component and system reliability are balanced.