To avoid unpractical optimal design without support

In some cases, topology optimization of continuum structures subjected to applied loads having a zero resultant force may result in an unpractical design without support. This phenomenon occurs because the original optimization problem neglects the possible change of the direction of applied load. This brief note sheds the light on avoiding such an unpractical design from the engineering viewpoint. In our work, this usually neglected phenomenon is systematically illustrated by employing a series of two-dimensional (2D) cantilever design problems using a simple and efficient Bi-directional Evolutionary Structural Optimization (BESO) method. An alternative scheme is further recommended to tackle the concerned conundrum. The proposed scheme not only can avoid unpractical designs without any support, but also takes into account the inherent uncertainty property in designing actual engineering structures.