DYNAMIC IMPACT BETWEEN A VISCOELASTIC ICE-FLOE AND A RIGID STRUCTURE

A one-dimensional wave analysis of the stress and velocity in a unifor m ice plate impacting a rigid structure at low velocity, driven by the net effects of wind and ocean drag, determines the histories of stres s on the structure and the motion of the plate. A linear viscoelastic ice response law is adopted which incorporates primary, secondary and tertiary creep effects consistent with observed (non-linear) response at a constant stress chosen to be a typical maximum magnitude. The lin ear elastic solution is a trivial special case. Comparisons are made w ith the corresponding quasistatic analysis, which neglects the non-rig id body accelerations and wave effects. A quasistatic treatment may be considered an appropriate approximation for low velocity impact, but the comparisons show otherwise. A non-linear elastic quasistatic solut ion is also compared.