Examination of SHPB Type Impact Fracture Toughness Testing Method by Dynamic Finite Element Analysis
Mitsugu TODO, Asami TANAKA and Kazuo ARAKAWA
Abstract:Split Hopkinson Pressure Bar (SHPB) technique has been used to evaluate dynamic fracture toughness values of metal, polymer and composites. There are some attempts for such SHPB toughness testing that conventional static equation is applied to evaluate toughness under high speed loading condition by introducing gradually accelerating load to the specimen. In this study, dynamic finite element analysis was performed to simulate a SHPB type toughness test with use of rubber buffer. A 2-D model including viscoelastic behavior of polymer specimen was developed, and it was found that the dynamic behavior experimentally obtained was well simulated using the model. Limitation of the use of the static analysis for impact toughness evaluation was also examined by considering acceleration effect on the stress intensity factor. The analytical result exhibited that the static analysis can be applied to estimate impact toughness values at acceleration lower than 2x104m/s2. Key Words:Split Hopkinson Bar, Finite element analysis, Fracture toughness, Polymer, Bending vibration