Experimental characterization and numerical investigation on different conformal lattice structures for specific energy absorption under quasi-static and dynamic loading

Abstract

Lattice structures exhibit significant potential for superior energy absorption under both static and dynamic loading conditions when compared to solid infill designs. This advantage arises from their distinctive properties, including low relative density, high flexibility, and enhanced compressibility. In this study, a novel type of infill lattice structure, termed the Different Conformal Lattice Structure (DCLS), was developed. DCLS is constructed through the tessellation of Simple Cubic (SC), Body-Centered Cubic (BCC), and Face-Centered Cubic (FCC) lattice configurations. The lattice structures were designed using Fusion360, incorporating optimized infill geometries characterized by both constant and variable relative densities achieved by varying the strut diameters of the individual lattices. Fabrication was performed using the Stereolithography (SLA) process, and the structures were subjected to quasi-static compression testing on a dynamic universal testing machine. Additionally, dynamic characterization was conducted using a Split Hopkinson Pressure Bar (SHPB) apparatus, and the results were compared with finite element simulations. The Experimental findings revealed that specific DCLS configurations, particularly EVT-BFS-2.5, demonstrated exceptional performance, achieving the highest specific energy absorption (SEA) values, exceeding 28 MPa under dynamic loading. This represents an impressive 1866.97% increase compared to quasi-static testing. Finite element analysis corroborated these experimental results, showing excellent agreement and validating the accuracy of the simulations. The study underscores the potential of DCLS with optimized tessellation patterns to significantly enhance energy absorption capabilities. These findings position DCLS as a promising solution for applications demanding lightweight, high-performance energy-dissipative materials.