Quasi-static and low-velocity impact biaxial flexural fracture of aluminosilicate glass — An experimental and numerical study

In this study, the quasi-static biaxial fracture behavior of aluminosilicate glass is investigated via Ball-On-Ring (BOR) and Ring-On-Ring (ROR) tests aided by a three-dimensional Digital Image Correlation (3D-DIC) technique. In-plane strain field and out of plane deformation distribution during the loading process can be obtained by this test system, overcoming the problem of inaccurate displacement data provided by the loading machine. During the loading process, a uniform strain distribution field is formed below the load ring of the ROR specimen while a gradient strain distribution is built for the BOR specimens. For dynamic loading conditions, low-velocity impact BOR tests are conducted at velocities of 2 m/s and 4 m/s showing a dynamic strengthening effect and high-speed cameras provide detailed fracture and failure sequences of the glass plates. Finite Element Method (FEM) simulations with the JH-2 material model are carried out showing good consistency with experimental results for the quasi-static loading conditions. FEM coupled to Smooth Particle Hydrodynamics (FEM-SPH) technique is utilized for dynamic simulations to solve the element distortion and non-physical problems. The influence of the tensile strain rate effect on low-velocity impact behavior of aluminosilicate glass is analyzed in detail. The original JH-2 model does not provide a reasonable prediction of the dynamic tensile response of brittle materials and the model requires further modifications to describe the dynamic tensile fracture behavior. By introducing rate-dependence maximum hydrostatic tensile strength σ_t,max to the updated model, better predictions for the contact force and projectile residual velocity histories of low-velocity impact tests can be provided.