FORWARD-ACCELERATED SIMP FOR TOPOLOGY OPTIMIZATION OF LOAD-BEARING MACHINE PARTS

Abstract

A modification of the SIMP method for topology optimization of load-bearing elements of mechanical engineering structures is proposed – the FA-SIMP (Forward-Accelerated SIMP) algorithm, which combines an adaptive lookahead step governed by a FISTA-type momentum coefficient with a double box/volume projection of the lookahead point. The sensitivity is evaluated at a physically admissible lookahead point shifted along the previous descent direction, and an adaptive momentum restart reduces the risk of divergence in the non-convex problem. This approach makes it possible to assess not only the final stiffness of the optimized structure but also the stability of the iterative process under changes in geometry and discretization. The method is studied on compliance minimization of a cantilever beam for three configurations differing in physical size and finite-element mesh density. At the same volume fraction and iteration budget, FA-SIMP consistently reduces compliance (up to 3.95 %), grayness index (up to 10.90 %) and maximum displacement while preserving the prescribed mass and keeping the computation time practically unchanged, providing a mesh-stable acceleration of SIMP.