Multi-morphology cellular structure design with smooth transition of geometry and homogenized mechanical properties between adjacent cells

•Multi-morphology cellular structure design method was proposed ensuring smooth transition of geometry and homogenized mechanical property between adjacent unit cells.•Intermediate unit cells are optimized using a genetic algorithm under geometric and mechanical constraints.•Continuity is ensured by the variable cutting level-set method with a level-set model composed of intermediate unit cells and a continuous variable cutting surface.•Reduction of the maximum stress and improvement of elastic modulus were found via experiments and numerical tests.