Dynamic responses of steel plates under repeated ice impacts

The repeated ice floe impact events on polar ships and offshore structures are very common in ice region. The accumulated plastic deformation of structures under repeated ice impact loadings reflects directly the damage conditions in the structures and is thus an important and convenient parameter in engineering assessment. The aim of this paper is to study the dynamic responses of steel plates subjected to repeated ice impacts based on the experimental and numerical methods. The laboratory repeated impact tests between the steel plates and fresh water ice wedges were carried out by using horizontal impact test machine. For each ice impact test, the collision forces and plastic deformations of steel plates were investigated. Besides, the finite element simulations are conducted to estimate the accumulated plastic deformations of steel plates under repeated ice impacts, which show good agreement with experimental results. Moreover, the energy dissipation of ice and the energy absorption of plate in each ice impact are studied based on numerical results, and the energy criterion of pseudo shakedown phenomenon has been re-examined for steel plate under identical repeated ice impacts. This paper analyses the plastic deformation accumulation and energy-sharing mechanisms of steel plates subjected to repeated ice impact loadings, which can provide useful information for the evaluation of the structural safety of ice-classed ships.