Slamming Pressure Calculation Including Structural Elasticity

With the increase of velocity of the large ship and the wide application of the high performance ship(hydroplane, hovercraft, catamaran etc.),the impact between structure and fluid occurs frequently. The hull structure oftenly was assumed as a rigid body in former impact theories. In fact, when the impact happens, there is a strong interaction between fluid and structure. On the one hand liquid brought strong slamming pressure and on the other hand the liquid field was influenced by structure response.This paper discussed the hydroelastic analysis for the wedge-shaped structure and flat structure, also some structure optimization problems when considering elasticity.For the wedge-shaped structure, a set of equations were introduced based on orthotropic plate theory. The fluid field was dealed with by general Wagner theory , then the equations were solved by the Vlasov/Galevkin's method.The response of a wedge structure from theory contrasted with that from experiments.It shown that this method is valid and feasibile for the fluid-solid interaction problems. Further more, the influence of impact velocity,deadrise angle, plate thickness were discussed. Analysis indicated that the structural elasticity can reduce the slamming pressure.For the flat structure , the impact pressure and duration time were calculated by using some rigid body test value and numerical simulation results from reference. Then the vibration displacement and impact pressure were dealed with by the finite element software PATRAN/ NASTRAN and approximate disposal of engineering. Impact pressures were calculated at the different velocity, deadrise angle, plate thickness.Moreover some structure optimization problems were discussed at slamming pressure calculation when considering elasticity.