Docking collision analysis of jack-up platform based on penalty function method

The collision process of the two piece units of a jack up platform is simulated using the nonlinear dynamic finite element method. The penalty method contact algorithm is used for the state nonlinear problem during the collision process. The influence of various factors on the collision results is analyzed, including collision velocity, collision angle and friction coefficient. The calculation results show that the maximum von Mises stress appears at the interface between the two piece units of the split jack-up platform, under small collision velocity; while the collision velocity becomes bigger, the maximum von Mises stress appears at the connections of brace pipe to the platform leg and down part of the jack-up platform; Under the same collision velocity, the maximum von Mises stress and collision force increase linearly with collision angle with the increasing extent becoming bigger and bigger, and reach the maximum value when the collision angle equals 90°; The influence of friction could be neglected when the collision angle is vertical; though the influence increases gradually with the decrease of collision angle, it has little effect on collision results as a whole.