A computational study on the adiabatic shear banding development during plane-strain uniaxial and angled-biaxial dynamic compression of AISI 1045 steel

Abstract. This work studies the adiabatic shear banding (ASB) development during dynamic plane strain compression of AISI 1045 steel under uniaxial and biaxial loading. In the case of biaxial loading, the examined steel sample is of 5° inclination in order to provide a shear-compression stress state due to its angled loading state. The numerical analysis is conducted through structural-thermal-damage doubly coupled finite element models in LS-DYNA by implementing the thermo-viscoplastic Modified Johnson-Cook plasticity flow rule and damage law. The simulations revealed that angled compression increases the propensity to ASB formation due to the introduction of a shear-compression stress state, which facilitates the shear strain localization, leading to lower critical strain for ASB initiation. Also, ASBs initially form under X-shape while following their trace forms S-shaped ASBs at higher deformation levels, while in case of biaxial compression the ASBs can be clearly distinguished to a stronger and a weaker one according to the magnitude of their interior strain and temperature. Finally, thermal softening is observed to occur prior to damage softening, determining in this way the ASB genesis, in contrast to the damage softening, which dominates its later evolution and its progression to fracture.