Experimental Investigation of Wave Slamming on An Open Structure Supported Elastically

The superstructures of marine structures supported by the elastic legs and located in the splash zone will subject to violent wave slamming and vibrate consequently during storms. A series of model tests are carried out to investigate the wave impacting on the open structures supported elastically. Three kinds of models with different natural frequencies are designed. The characteristics of the wave pressures on the three models are compared. The durations of the uplift forces and the corresponding accelerations of the structure during wave impact are analyzed simultaneously. The distributions of the peak impact pressures on the subfaces of the plates with different supporting stiffness are given. The relationship between the uplift force on the three models and the relative clearance are obtained. The spectral properties of the slamming loads on the three different structures are compared, The experimental results indicate that the behaviors of the impact pressures, the uplift forces and accelerations of the plates with small natural frequencies are obviously different from those of the plates with larger natural frequencies within the range of the experimental parameters.

Numerical simulation of hydro-elastic problems with smoothed particle hydrodynamics method

Violent free surface flows with strong fluid-solid interactions can produce a tremendous pressure load on structures, resu- lting in elastic and even plastic deformations. Modeling hydro-elastic problems with structure deformations and a free surfaee breakup is difficult by using routine numerical methods. This paper presents an improved Smoothed Particle Hydrodynamics （SPH） method for modeling hydro-elastic problems. The fluid particles are used to model the free surface flows governed by Navier-Stokes equations, and the solid particles are used to model the dynamic movement and deformation of the elastic solid objects. The improved SPH method employs a Kernel Gradient Correction （KGC） technique to improve the computational accuracy and a Fluid-Solid Interface Treatment （FSIT） algorithm with the interface fluid and solid particles being treated as the virtual particles against their counterparts and a soft repulsive force to prevent the penetration and a corrective density approximation scheme to remove the numerical oscillations. Three typical numerical examples are simulated, including a head-on collision of two rubber rings, the dam break with an elastic gate and the water impact onto a forefront elastic plate. The obtained SPH results agree well with experimental observations and numerical results from other sources.

Dynamic analysis of wave slamming on plate with elastic support

Experiments are conducted to investigate the dynamic response of a plate with elastic support under a regular wave slamming. The statistical analysis results obtained in different model testing cases are presented. The theoretical analysis of the plate vibrations(including the forced and free vibrations) is performed. Four characteristic stages of the plate vibration accelerations between two consecutive wave impacts are identified. The submergence durations of the plate during the wave action and the hydro-elastic effects are discussed. Finally, some useful conclusions are drawn.