Optimization of an additively manufactured self-supporting lattice-filled clevis component under combined loading

Additively manufactured lattice structures are highly desirable in various fields because of their effectiveness in lightweight design and superior mechanical properties. Even with increasing popularity in different manufacturing fields, the requirement for post-processing and the limited usage of enclosed volume remains challenging. Therefore, the study investigates strut-based self-supported lattice design variables on mechanical properties via experimental validation and optimization. The clevis bracket, which is infilled with 3-, 4-, and 6-fold self-supporting lattice, is subjected to combined loading to simulate real case scenarios. Compression-shear and tension-shear loads were applied to the clevis while changing its variables: strut diameter, height, and overhang angle. The design is manufactured using the fused deposition modeling (FDM) with polylactic acid (PLA) material. The finite element model is validated with experimental results of manufactured specimens. Bayesian optimization (BO) algorithm minimizes stress and maximizes weight-saving value by alternating lattice type and its variables. The compression-shear performance of each specimen is much better than the tension-shear performance. While a 3-fold lattice gives the best result and broad design flexibility, a 6-fold lattice has the lowest performance. By changing variables, nearly the same result can be achieved for 3- and 4-fold strut lattices. The results show that significant weight saving is possible by using a self-supported lattice design.