Damage mechanism of Aluminosilicate glass under low-velocity hard impact: An experimental and numerical investigation

Aluminosilicate glass is increasingly finding applications in the defense and aerospace industry due to its superior impact-resistant properties. However, these products are inevitably prone to impact during their service, resulting in a catastrophic failure. Hence, it is cardinal to analyze the behavior of constituting glass elements under desired service conditions for rendering robust and efficient product design. This study is aimed to investigate the dynamic flexure behavior of Aluminosilicate glass under a three-point flexural configuration. Indigenously developed Electromagnetic Split Hopkinson Pressure Bar (ESHPB) was introduced. High-speed reprography was performed to evaluate the damage mechanism. It is elicited that stresses induced due to the bending on the tensile face of the specimen are the root cause of failure for low-velocity hard impact scenarios simulated in the study. Results of the experiments were numerically simulated in an explicit dynamic solver, and a calibrated Johnson-Holmquist (JH-2) model was employed as a material model. Systematic numerical evaluation of the JH-2 model revealed that peak failure stress is not mesh-dependent. Instead, the failure time monotonically decreases with the decrease in mesh size. It is established that under low-velocity hard impact scenarios, the proposed simulation algorithm can successfully mimic experimentally observed failure modes and stresses.