| Abstract Scope |
In order to model a vehicle crash event using the finite element method (FEM), accurate material properties at high strain rates are required. However, high-speed loading always results in structural vibration, which deteriorates the quality of the force measurement in a conventional tensile testing machine. Therefore, it has been a challenge for long to produce reliable experimental data under high strain rates for both deformation and failure description of engineering materials. In this work, a newly proposed high-speed testing approach with a specific specimen geometry and an oscillation-free force measurement method is applied to study the mechanical properties of a steel sheet. In addition to the plasticity behavior description by regular tensile tests, fracture specimens with various geometries, such as the central hole, notched dog-bone, plane-strain, and shear specimens, are designed and tested from quasi-static to 1000/s. The deformation fields and local strains at failure are measured using digital image correlation (DIC) method. The influences of stress states and strain rates on deformation and failure behavior of the investigated steel are presented and discussed. |