Impulsive Interaction of Breaking Waves with Flexible Coastal Structures

Abstract

The problem of impact of a water wave with flat front onto an elastic vertical plate which models the surface of a coastal structure is studied. The liquid is assumed weakly-compressible; the liquid flow is described within acoustic approximation. The deflection of the plate and its vibrations caused by impact are described by a linear theory of thin isotropic plates without accounting for shear stresses. The hydrodynamic and structural parts of the problem are coupled by both dynamic and kinematic conditions imposed on the wetted part of the structure. The problem is solved by the normal mode method. By using integral transforms the problem is reduced to a system of differential and integral equations which are numerically solved. Phenomena caused by the structural damping and liquid compressibility are investigated. It is shown that the structural damping affects the global evolution of the plate behavior; however, maximum deflection and maximum bending stress can be determined without account for structural damping. New combined model of violent wave impact is proposed. Within this model only the early stage of impact is described with taking the liquid compressibility into account, the later stage is simulated by using the model of incompressible liquid.