Three-dimensional cylindrical truss structures: A case study for topological optimization

Abstract

A general minimum-weight cylindrical structural layout for the support of any combination of axial and torsional loading has been developed. The principal intention in this work is to provide a test case for 3-dimensional numerical topological optimization. It is anticipated that the solution may present a challenge, since for the small angular spacing of the truss elements the internal radial force component is always of the order of magnitude of the angular spacing for any arbitrary selected pair of helix families. Moreover for a wide range of solutions slender members are an essential part of the topology. A novel finite element topology optimization procedure is presented based on the application of Beta probability density and cumulative distribution functions. The procedure utilizes a family of Beta functions which provide a smooth transition from a uniform to a bi-modal density distribution, with constant probability mean to conserve constant mass. © 2009 WIT Press.