Fracture Strength Based Optimisation of Thin-Walled Structures using Modified ESO
Research into damage tolerance based optimisation undertaken to date is quite limited due to complexity and computational inefficiency associated with the explicit modelling of cracks. The present paper presents a modified Evolutionary Structural Optimisation algorithm for shape optimisation of thin-walled structures with strength and durability as design objectives. In this formulation, cracks are assumed to be (potentially) present at all possible locations along the boundary being optimised. The optimisation process is integrated with the commercial finite element analysis program NE-NASTRAN. This facilitates its use for design optimisation of real life engineering structures. The effectiveness and efficiency of this formulation is illustrated by a fillet design problem. It is found that the fracture based ESO reduces the maximum stress intensity factor along the optimum fillet profile significantly and produces a shape equally fracture critical everywhere. The results obtained here agree with those reported in the literature using another recently developed method.