RELIABILITY-BASED DESIGN OPTIMIZATION OF STRUCTURES: AN INVESTIGATION ON PLANAR STRUCTURES

Tóm tắt

Structural optimization is a crucial approach for achieving rational design solutions, in which cost is commonly set as the objective to be minimized. Two primary approaches are typically employed: deterministic-based optimization and reliability-based optimization. To address the inherent uncertainties in structural performance, this study proposes a procedure for optimizing structures to satisfy both deterministic and probabilistic constraints. In this framework, the problem is formulated to incorporate probabilistic safety requirements, and Monte Carlo simulation is used to estimate the failure probability at each iteration of the optimization process. Three illustrative examples are presented to demonstrate the effectiveness of the proposed procedure for planar structures. The results from the reliability-based approach are examined for different levels of probabilistic constraints, and the influence of including uncertain variables is investigated in the first two examples. The findings show that the reliability-based approach generally results in larger element sections and, consequently, higher investment costs when lower target failure probabilities are specified, and greater weight is required when additional uncertain variables are considered. Finally, the proposed procedure is shown to perform well for problems defined implicitly and involving both deterministic and probabilistic constraints, as evidenced in Example 3.