The present study proposes a multi-material topology optimization method considering the strengths both of solid materials and interface. In order to consider multiple factors of Young’s modulus and strength at the same time, the DMO material interpolation function that the coefficients are given equivalently is applied. To resolve the singularity problem, we propose the stress definition adapted to the DMO material interpolation function. Furthermore, the graded interface with a two-step density filter is introduced to represent the interface on a density-based method. The tension/compression asymmetric interfacial strength criteria makes it possible to obtain an optimal layout in which the interface is not subjected to tensile strain. The validity of the method proposed in this study is verified with three structural models.
