en Optimal design Optimal design پژوهشي Research In this paper the piecewise level set method is combined with phase field method to solve the shape and topology optimization problem. First, the optimization problem is formed based on piecewise constant level set method then is updated using the energy term of phase field equations. The resulting diffusion equation which updates the level set function and optimization problem is solved through finite element method. The proposed method enhances the convergence rate and solution efficiency. Various two-dimensional examples are solved to verify the performance of proposed method. topology optimization, level set method, phase field method, piecewise constant level set method, finite element method. 389 407 http://ijoce.iust.ac.ir/browse.php?a_code=A-10-66-74&slc_lang=en&sid=1 S. Shojaee 18003194753284600853 18003194753284600853 Yes A. Mohaghegh 18003194753284600854 18003194753284600854 No A. Haeri 18003194753284600855 18003194753284600855 No