Topology Optimization

Theory

Topology optimization (TO) treats each voxel of the design space as a design variable with density between 0 (void) and 1 (solid). A finite-element solver iteratively removes underloaded voxels while satisfying stiffness, stress or frequency constraints under defined load cases. The output, an STL or implicit body, is geometrically complex with internal voids and organic load paths that only AM can realize without assembly.

Application

TO is most powerful for DMLS/SLS aerospace brackets, titanium medical implants and automotive end-effectors where mass-to-stiffness ratio is critical. Workflow: define envelope + loads in FEA (Ansys Additive, Altair OptiStruct, nTopology) → run TO → smooth and interpret organic result → validate → print. GE Aviation's LEAP fuel nozzle achieved 25% mass reduction via TO + DMLS.

Common mistakes

Raw TO output is not print-ready: thin struts may violate minimum wall rules; overhangs can violate 45° DMLS limits. Always run a DfAM check after interpretation. Minimum member size must be explicitly constrained inside the optimizer to avoid unprintable features.

Related terms: Lattice & Gyroid Structures, Generative Design, Lightweighting / Mass Reduction