A tri-axial ice model for simulating ice-stiffened panel impact: Experiments and numerical modeling

Abstract

The interaction of ice with a polar ship is complex, which may involve several ice failure mechanisms such as local crushing, tensile, cracking, bending, shearing, sliding and the ship structures could attain permanent deformations. A reasonable modeling of ice behavior is, therefore, critical to the analysis of ship-ice interactions. This paper reports an experimental and numerical study on the behavior of stiffened panels subject to the impact of a wedge-shaped ice block/indenter. The tested stiffened panel was mounted to a Falling Weight Impact Tester, and measurements were taken to help understand the dynamic responses of the structure and the ice, and also the permanent deformations. Finite element analyses using ABAQUS/EXPLICIT were also performed for the lab tests. The proposed ice model features a multi-surface yield function, empirical failure criteria for a few ice failure modes, and a representation of the remaining load carrying capacity of crushed ice. This ice model is implemented in a user-defined subroutine VUMAT and uses the cohesive element in a numerical solution. The predicted and measured impact force and structural deformation compared very well with the tests, indicating that the proposed ice model coded in VUMAT is reasonable. A series of parametric studies was then carried out to identify the key parameters of this new ice model that would have major effects on the prediction of ice impacts. The paper intends to provide test data that may be useful in understanding the complex ice-ship interaction and to introduce a numerical solution with a new ice model that improves the simulation of high-energy ice-ship impacts.