An Experimental And Numerical Investigation Of Slamming On Wedges With Different Stiffness

Slamming occurs on the bow of river-to-sea ship which is broad and flat because of the waterways’ restriction. Compared with the sea-going vessel, the slamming problem of river-to-sea ship is different. In this paper, a wedge with deadrise angle of45°was used to simulate the flare of the bow of river-to-sea ship, and experimental method and numerical method were applied to investigate the slamming of the wedges with different types of stiffness. The slamming pressure on the models, the duration and the structural responses were recorded, while the characteristics of the loads and structural responses were calculated by the Non-linear FEM method. The following efforts have been made and the conclusions are presented:1) The wedges with different types of stiffness were designed, and a series drop tests were carried out. The process of slamming of the wedge model, the slamming pressure on the model and the structural response of the model were recorded. Some conclusions were obtained:a) The peak value of slamming pressure on the elastic model is smaller than the pressure on the rigid model, while the duration of the peak value of the slamming pressure on the elastic model is larger than the duration of the rigid model.b) Slamming pressure on the wedge increase with the impact speed and decrease with the increase of immersion depth, whilst the slamming pressure remains stable at the longitudinal directions.c) The structural response increase with the impact speed and the stress level of the transverse stiffness is highest, and the stress level of the longitudinal stiffness is in the middle, while the stress level of the plate is lowest.2) The water entry problem of the wedges with different types of stiffness were calculated by using the non-linear FEM method, and the difference between the elastic model and rigid model were studied. Meanwhile, the effect of the change of plate thickness and frames on the slamming pressure and structural response were investigated. Some conclusions were obtained:a) Good agreement of slamming pressure and stress responses on models between numerical results and experimental data in time domain is achieved,b) The structural response is not sensitive to plate thickness, and it is reasonable that increase the transverse frames is more effective to reduce the global structural response on the model.