Virtual-trim: A parametric geometric modeling method for heterogeneous strut-based lattice structures

Geometric modeling has been integral to the design process with the introduction of Computer-Aided Design. With Additive Manufacturing (AM), design freedom has reached new heights, allowing for the production of complex lattice structures not feasible with traditional manufacturing methods. However, there remains a significant challenge in the geometric modeling of these lattice structures, especially for heterogeneous strut-based lattice structures. Current methods show limitations in accuracy or geometric control. This paper presents the Virtual-Trim, a novel method for the geometric modeling of heterogeneous strut-based lattice structures that is both efficient and robust. Virtual-Trim begins with user-defined wireframe models and geometric information to create STL models ready for AM, eliminating the need for labor-intensive Boolean operations. The fundamental principles and steps involved in Virtual-Trim are extensively described within. Additionally, various models using Virtual-Trim method are designed, and the performance of Virtual-Trim in terms of generation time and model size is analyzed. The successful printing of these models attests to the method's excellent manufacturability.