The strain rate effect of reinforcing steel bars is generally indispensable for modeling the dynamic responses of reinforced concrete structures in blast and impact events. A systematic experimental investigation was conducted on the strain rate behavior of reinforcing steel bar grades HPB235, HRB335, HRB400, and HRB500 which are widely used in the field of civil engineering in China. The dynam...

Because of their superior ballistic and mechanical properties, lightweight materials like titanium alloy Ti-6Al-4V and aluminum alloy AA5083-H116 have been frequently used for aerospace and military applications. Tests of ballistic limit velocity are limited by expensive nature of the experimental setup, and indeed, that can be resolved by adopting numerical simulations. Numerical study involvi...

Extraction of the material stress-strain curve from a dynamic tensile or shear experiment is not straightforward. Indeed, stress and strain are not homogeneously distributed in the specimen, and consequently no one-one relation exists between the measured elongation and strain on one hand, and the measured force and stress on the other hand. This work aims at improving the accuracy of the stres...

A new modified Johnson-Cook model is developed to capture the non-linear thermal softening behaviour below austenite transformation temperature (723°C) in C45 ferritic-pearlitic steel, which not captured by original (JC) model. The physical mechanisms responsible for this are also studied. experimental quasi-static and high strain rate axisymmetric compression testing from 20°C 720°C implemente...

We present a force-displacement contact model for the compressive loading of elastoplastic spheres. This model builds from the well known Hertz contact law for elastic, quasistatic compression to incorporate a material's strain-rate-dependent plasticity in order to describe collisions between particles. In the quasistatic regime, finite-element analysis is used to derive an empirical function o...

The material properties of OFHC copper film was investigated with the High-Speed Material Micro Testing Machine (HSMMTM) at the high strain rates. The rate-dependent stress-strain curves from the experiment and the Johnson−Cook curve fitting showed large discrepancies as the plastic strain increases since the constitutive model implies no rate-dependent strain hardening effect. A new constituti...