Failure analysis on wave compensator and hull structure of trailing suction hopper dredger (TSHD) under Medium-Long period wave

Abstract

In the process of dredging construction, the trailing suction dredger (TSHD) in the medium-long period waves usually encounters a violent 6-DOF (six degree of freedom) motion. It may lead to the failure of the wave compensator beyond its stroke, and also the failure of structural strength due to the impact of drag arm. Based on the CFD method, the motion simulation of a 10000 m3 TSHD under medium-long period waves is carried out, the most violent condition is found as wave height of 3.5 m, period of 12 s, and direction of 90°, with the peak values of roll and heave are 10.84° and 1.18 m. For TSHD under dredging state, the stress on hull and drag arm is calculated. FEM simulation is used to analyze the structural dynamic response and strength failure of the hull structure in collision with drag arm. Finally, the impact of wave conditions on the collision between drag arm and hull is summarized, and the basic safe wave conditions for the failure of the drag arm, hull, and wave compensator are determined to guide the construction safety of TSHD.