Numerical Study of Repeated Low-Velocity Impact Effects on Flat and Convex Surface of SUS304 Plates via Finite Element Method

Abstract

This study quantifies how surface curvature reshapes force transmission and local plasticity in SUS304 plates subjected to machine-driven reciprocating low-velocity impact. A flat target and a convex target of identical outer dimensions (D = 120.06 mm, H = 119.9 mm) are compared, where the convex surface is defined by a spherical cap of sag height h_c = 5 mm (curvature radius R_c = 362.86 mm). All simulations are performed in Abaqus/Explicit 2024 using a deformable target discretized with reduced-integration solid elements and a rigid striker with lumped mass. To ensure generality, a parametric sweep is conducted using two striker masses (0.5 kg and 0.8 kg) under identical prescribed reciprocating velocity. For the 0.8 kg case, convexity reduces the peak reaction force from 2.965 × 10⁶ N to 2.009 × 10⁶ N (32.3%) and reduces the peak indentation from 2.500 mm to 2.001 mm (20.0%), while increasing the final plastic dissipation from 1002.25 J to 1560.93 J (55.8%) and increasing the peak equivalent plastic strain from 0.00710 to 0.03476 (389.6%). These results demonstrate a curvature-driven trade-off in which convex geometry mitigates transmitted peak load yet intensifies localized plastic accumulation beneath the contact zone. Numerical robustness is established through a three-level mesh convergence study and a damage-evolution sensitivity analysis; varying the fracture displacement parameter by ±50% produces negligible changes in the global force–indentation response, confirming the stability of the predicted curvature effects.