Optimal topology design of industrial structures using an evolutionary algorithm

The paper demonstrates the application of a modified Evolutionary Structural Optimisation (ESO) algorithm for optimal design of topologies for complex structures. A new approach for adaptively controlling the material elimination and a ‘gauss point average stress’ is used as the ESO criterion in order to reduce the generation of checkerboard patterns in the resultant optimal topologies. Also, a convergence criterion is used to examine the uniformity of strength throughout a structure. The ESO algorithm is validated by comparing the ESO based solution with the result obtained using another numerical optimisation method (SIMP). The capabilities of ESO for producing an optimal design against a specified strength constraint are illustrated using two industrial design problems, viz: a bulkhead used in an aircraft structure and a sideframe used in a railway freight wagon. It has been shown that topology optimisation using ESO can result in a considerable reduction in the weight of a structure and an optimum material utilisation by generating a uniformly stressed structure. The ESO algorithm was also applied to the shape optimisation of a local geometry of the sideframe to (locally) reduce stress levels. The paper evaluates and establishes the ESO method as a practical tool for optimum topology and subsequent shape design problems for complex industrial structures.