Strength Calculation And Analysis Of Crude Oil Ships On Launching Way

Ship launching is the key procedure during ship building, most coastal shipyard adopt longitudinal gravity launching method, the existing method for calculating ship launching include regular hydrostatic method and elastic calculation of ship launching. At present, more and more large tonnage ships are built with the development of ship Industry, the force between hull and shipway increased, the damage of ship structure was also reported. But the existed method is not efficiently for calculating the distribution of force acted on forward during stern floating which is the moment of truth during ship launching, so it is important to calculate ship launching precisely and take measure to preclude such accident.In order to solve this problem, the distribution of the force was studied. With analyzing the data of ship launching, the paper educes seven typical distribution forms, include uniform distribution, sine distribution (1/2 amplitude), trapezoid distribution, right triangle distribution, sine distribution (1/4 amplitude), parabola distribution, isosceles triangle distribution. Stress and deformation was calculated with the distribution to predict the security of structure where FEM is used.With calculating in method of FEM, the paper gives some advice on how to design structures of ship launching.