A novel Angle-Constrained Optimization method of Conformal Lattice Structures

Conformal truss-like lattice structures face significant manufacturability challenges in additive manufacturing due to overhang angle limitations. To address this problem, we propose a novel angle-constrained optimization method grounded in the global adjustment of nodal coordinates. First, a build direction is selected to minimize the number of violating struts. Then, an angular-constraint matrix is assembled from strut direction vectors, and analytical sensitivities with respect to nodal coordinates are derived to enable efficient constrained optimization under nonlinear angular inequality constraints. Numerical studies on two complex curved-surface lattices demonstrate that all overhang violations are eliminated while only minor changes are induced in global stiffness and strength. In particular, the maximum displacement of an ergonomic insole varies by only 2.87% after optimization. The results confirm the method’s versatility and engineering robustness, providing a practical approach for additive manufacturing-oriented lattice structure design.