We present a review of the solutions for several 2-D and 3-D pr oblems. The timeharmonicproblem describing small o scillations (sway\, heave and roll) of a horizonta lcylinder is considered for four classes of hydroe lastic system: i) a floating semiinfiniteelastic p late\; ii) two semi-infinite elastic plates connec ted by the vertical andflexural rotational springs as a model of a partially frozen crack in an ice sheet\; iii) afloating elastic platform of finite length\; iv) two semi-infinite elastic plates sepa ratedby a region of open water (polynya). The hydr odynamic load (added mass anddamping coefficients) and the amplitudes of vertical displacements of t he free surfaceand elastic plates are calculated a s functions of the cylinder oscillation frequency andthe location of the cylinder with respect to th e plate edges.

The 3-D problem is considere d for time-periodic external pressure and a load u niformly moving along the rectilinear edge of the ice cover. By analogy with the 2-D case\, the firs t two classes of hydroelastic system are considere d\, as well as the effect of the solid vertical wa ll while the edge of the ice cover adjacent to the wall can be either clamped or free. In the proble m of time-periodic external pressure\, it is shown that for semi-infinite elastic plate contacting w ith free surface of water and for two non-identica l semi-infinite plates\, divided by crack\, the di rections of predominantwave propagation are alloca ted under some angle to the crack. In the case of two identical semi-infinite plates\, divided by a crack\, the edge wave guide mode is excited.The ed ge wave is most excited is the case of semi-infini te plate with a free edge near a solid vertical wa ll.

In the case of moving load\, the 3-D pi ctures of generated waves in fluid and in ice cove r are built for various speeds of motion. It is sh own that in case of two identical semi-infinite pl ates\, divided by a crack\, two edge waveguide mod es with different wave numbers exist for supercrit ical values of speed motion. For the vehicle movin g with supercritical speed one mode is extending i n front of moving load and other mode behind it. T he wave forces acting on moving vehicle are invest igated for \;various speeds of motion. LOCATION:Seminar Room 1\, Newton Institute CONTACT:INI IT END:VEVENT END:VCALENDAR