Multiobjective structural optimization of frameworks using enumerative topology

•Enumerative topology is proposed, a new method for optimizing in conceptual design.•An Evolution Strategy working with populations of solutions of differing lengths.•Dimensional increments appear to increase consistency of optimization results.

The paper describes a multiobjective optimization method aimed at supporting decisions in conceptual design. The paper identifies five characteristics to achieve this intent. One of those characteristics concerns accounting for variation configuration. The method introduces enumerative topology, a way of specifying structural configuration in terms of enumerative variables, such as the number of bays in a truss or frame. This concept is distinct from conventional topological optimization which defines configuration by specifying the presence or absence of members in a framework. The paper demonstrates the method on two benchmark problems, and then presents extended versions which incorporate enumerative topology.