Abstract
This article deals with the reliability based geometry and topology optimization of truss structures. It presents an approach to optimize simultaneously the geometry and topology of statically undetermined trusses considering the acting forces and the yielding stress of the bars as random variables. Based on the assumptions of linear structural behaviour and independent and normally distributed random variables, the optimization problem is posed in such a way that its computational cost is similar to a standard deterministic optimization problem, which is the main contribution of this study. It is shown in the numerical analysis that when uncertainties are considered, the resulting optimum structure may not be a simply scaled version of the deterministic solution, but there may be a change in the structural geometry as well.