A simulation study on the ice fracture behaviors in ice-lighthouse interaction considering initial defects in ice sheet

摘要

With the increasing marine activities in the Arctic area, the demand for reliable designs of marine structures in this area is growing. There have been many studies published regarding simulation of ice-marine structure interaction. In these studies, ice models are established without considering initial defects. However, natural ice usually contains lots of initial defects including cracks, inclusions, pores, etc. In this paper, this issue is studied by applying defect model and cohesive element method (CEM). Several ice bulk elements labeled as initial defects are deleted from the ice sheet. Then, cohesive elements are inserted in the ice sheet model that is meshed with tetrahedron elements. Collision between ice sheet and a lighthouse is simulated in full scale. Initiation and propagation of ice sheet cracks are achieved by deleting the cohesive elements that reach fracture energy. Horizontal force and failure process of ice sheet are analyzed. The results show that the initial defects can affect both the horizontal force and fracture of ice sheet. Then, a series of simulations in terms of distribution, percentage and size of ice sheet defects are performed. Effects of these factors on the horizontal force and crack propagation are discussed.