Investigating the Strain Rate Sensitivity and Mechanical Behavior of Photopolymer Base Cellular Structures: Focus on Base Material and Cell-Graded Gyroid Structures

KUHLJEVI DNEVI 2023, Maribor, Slovenya, 21 - 22 Eylül 2023, ss.227-236

This study aims to enhance the understanding of the mechanical behavior of cellular

structures, with a particular focus on the strain rate sensitivity of the base material. Cellular

structures are known for their exceptional mechanical properties, presenting challenges in

comprehending their complex behavior influenced by factors such as strain rate sensitivity, inertia,

and morphology. To address these challenges, a comprehensive investigation combining

experimental and computational approaches was conducted. Experimental analysis revealed a

critical strain rate range, indicating that the material displayed ductile behavior below 0.8 s-1

,transitioning to a highly brittle state above 1.67 s-1. Furthermore, the onset of brittleness occurred at

deformation rates exceeding this threshold. Computational simulations and experimental analysis

demonstrated that the response of the base material was predominantly governed by its strain rate

dependency rather than inertial effects. In addition to investigating the behavior of the base material,

the study also explored the mechanical characteristics of cell-grade gyroid structures. These unique

structures exhibited distinct properties attributed to their porous morphology, specifically their "long

plateau" configuration. Remarkably, the structures demonstrated a hardening effect when subjected

to rapid deformations. This observed hardening phenomenon can be attributed to the strain rate

sensitivity of the base material, highlighting its significant role in shaping the overall mechanical

behavior.