Anisotropic Mesh Adaptation, the Method of Moving Asymptotes and the global p-norm Stress Constraint

The p-norm often used in stress constrained topology optimisation supposedly mimics a delta function and it is thus characterised by a small length scale, and the same should apply for the solid-void transition. We propose to resolve these features using anisotropic mesh adaptation. We use the method of moving asymptotes with interpolation of sensitivities, asymptotes and design variables between iterations. We demonstrate this combination for the L-bracket problem with p=10, and we are able to investigate mesh dependence. Finally, we find that the method of moving asymptotes benefits from a relaxation of the problem statement from a geometry with a sharp corner to one with a rounded corner, even if the corner radius is only 1% of the characteristic length scale.