Concurrent optimization of additive manufacturing fabricated lattice structures for natural frequencies

Abstract

Lattice structures exhibit enormous potential for multi-functional implementations for their high stiffness/ strength-to-weight ratio. While Additive Manufacturing (AM) techniques present great opportunities in the application of lattice structures, its process limitations impose challenges in design for AM. This paper develops a concurrent design method of AM fabricated lattice structures and its printing part orientation in natural frequency optimization problems. Specifically, void units are introduced into the design domain for better frequency objectives. Density filtering and projection approaches are designed to consider the Minimum Feature Size and the self-supporting constraints. Further, a concurrent optimization model is constructed to optimize the unit density layout and the part orientation. The proposed method was validated with a fundamental frequency optimization problem. Numerically, the proposed concurrent optimization method achieves high-quality solutions with low computational costs. Experimentally, the structure designed by the proposed method exhibits a higher fundamental frequency than that designed by the comparison method.