Structural optimisation based on the boundary element and level set methods

•A level set based structural optimisation method is presented.•The bi-directional evolutionary optimisation approach is used with BEM.•The proposed method provides automatic insertion and merging of holes.•NURBS were used to represent the structural geometry segments.

A new method of structural topology optimisation is proposed in which an evolutionary approach is used with boundary element and level set methods. During the optimisation iterations, the proposed method automatically introduces internal cavities and does not rely on an initial guess topology with pre-existing holes. The zero level set contours describing both the external geometry and the internal cavities are converted to non-uniform rational B-splines (NURBS) for smooth boundary element meshing at each iteration. The optimal geometries generated by the proposed method for two-dimensional cases closely resemble to those available in the literature for a range of benchmark examples in the field of topology optimisation.