TOPOLOGY OPTIMIZATION OF CONTINUUM STRUCTURES WITH UNCERTAINTY IN LOADING DIRECTION

Uncertainty in applied loads is a vital factor that needs to be considered in the design of the engineering structures. This paper concerns the minimization of mean compliance for continuum structures subjected to directional uncertain applied loads. Due to the uncertain behaviour of this type of the optimization problem, the existed deterministic topology optimization methods are not able to solve such problems. The loading directional uncertainty is described by directional interval variables which are divided into many small intervals, and then the uncertain small interval variables are approximated by their deterministic midpoints. In doing so, the uncertain topology optimization problem is transformed into deterministic multiple load case one. The optimization problem is then formulated as minimizing the mean compliance under multiple load cases, subject to material volume constraint. A soft-kill bidirectional evolutionary structural optimization (BESO) method is developed to solve the problem, which requires very few changes to the BESO computer code. The results reported in this work show that the proposed methodology suits engineering design and represents an improvement over existing topology optimization methods.