A method for optimizing the design of support structures for Powder Bed Laser Fusion (PBLF) manufacturing is presented. The method involves an octree adaptive layer-wise thermo- mechanical finite element process simulation, where the design sensitivities of the objective function and/or constraints are computed via the adjoint method. The optimization problem is solved using the Method of Moving Asymptotes (MMA). The proposed approach is exemplified in the support optimization for control of the inter-layer temperature and the minimization of recoater interference in PBLF. The support structures are modeled as homogenized elements and the design variable vector is the homogenization volume fraction of all support elements. The objective function is the minimization of the support structure mass. The constraint function for the thermal problem is set as the peak allowable interlayer temperature. For the mechanical problem, the constraint function is set to the allowable recoater clearance. The possibility of extending the approach to part design optimization will also be discussed.
Learning Objectives:
- Describe the adjoint method and the method of moving asymptotes, as well as their usefulness for solving optimization problems with many design variables.
- Define problem statements for input into additive manufacturing build prep optimization models.
