DYNAMIC PLASTIC ANALYSIS OF SHIP-PLATFORM COLLISION

This paper studies intensively the problems of ship-platform collision . The ship and platform are treated as one structural system connected with spring elements and then motion equation of the collision system is established. A nonlinear force-displacement relationship is derive d for the simulation of local dent in a hit member and the yield surfa ce of a dented tubular section is developed to consider the reduction of load carrying capacity of hit members. Large deformations, plastici ty and strain-hardening of the beam-column element are taken into acco unt by combining the elastic large displacement analysis theory with t he plastic node method. The effect of the hydrodynamic forces acting o n the platform, the rubber fender the property of the local dent and t he buckling behavior of beam-column on collision are analyzed. The num erical simulation of the nonlinear dynamic response is carried out by Wilson theta method with updated Newton-Raphson iteration. And the num erical example of the dynamic response of a offshore platform in ship- platform collision is also present.