Nonlinear dynamic response of steel materials and plain plate systems to impact loads: Review and validation

A finite element analysis (FEA) model to evaluate the nonlinear effects of severe dynamic loads on engineered structures requires an appropriate constitutive model of the structural material. Although some dynamic constitutive models for steels including mild and high strength steels are specified in offshore design guidelines, their limitations when applied to analysis of severe impact effects haven't been examined in any details. This paper demonstrates that the structural performance of a steel plate system subjected to impact load of a dropped object is highly sensitive to the adopted dynamic constitutive model using an existing experimental study. The stress-strain response of the plate is strongly dependent on the mechanical and geometrical properties of the steel specimen and the strain rate due to the impact load. While the dynamic constitutive model recommended by Det Norske Veritas (DNV) often overestimates or underestimates the structural response due to impact load, the proposed constitutive model leads to a significant improvement in the DNV recommendations.