Experimental Evaluation of Strut-Based Mesostructures: Brittle Behavior and Energy Absorption

Abstract

This study investigates the compressive energy absorption behavior of parametrically defined, strut-based mesostructures fabricated using stereolithography additive manufacturing. Lattice specimens with four distinct geometries—body-centered cubic, octet, re-entrant, and Kelvin cell—were designed using implicit modeling, maintaining constant relative density and unit cell dimensions to enable direct comparison of structural efficiency. Specimens were printed with Formlabs Clear resin, chosen for its superior energy absorption and elastic properties, and subjected to uniaxial compression testing using a Tinius Olsen universal testing machine. Experimental protocols ensured uniform loading and minimized size-dependent effects. Force–displacement data were processed to quantify energy absorption and benchmarked against prior literature and other mesostructure types using Ashby plots and bar chart visualizations. Results reveal that all strut-based lattices exhibited predominantly brittle behavior under compressive loading, characterized by abrupt failure and limited plastic deformation. Compared with serpentine and plate-based mesostructures, which show more ductile and progressive energy dissipation, the tested strut-based designs absorbed less energy and failed at higher densities. This study highlights the critical influence of lattice topology on mechanical response, demonstrating that slender strut-based architectures concentrate stress and are prone to catastrophic fracture, whereas alternative geometries, such as serpentine and plate-based lattices, facilitate distributed deformation and superior energy absorption. These findings underscore the importance of geometric innovation in the design of architected materials for impact mitigation and energy-absorbing applications. The research identifies current limitations associated with strut-based periodic lattices and points to future directions involving plate-based, hybrid, and multiscale lattice architectures. Integrating computational modeling with experimental validation is recommended for optimizing both geometry and material properties, ultimately advancing the functional performance of energy-absorbing mesostructures.