A random ice force model for narrow conical structures

This paper describes a time-varying random ice force model for narrow conical structures. The model concerns a situation where a uniform ice sheet acts on a narrow cone and fails by bending in a mode where the broken ice pieces are cleared away. The ice force is simplified as a series of impulses with random magnitudes and periods, which are based on a statistical analysis of the load panel data obtained in full scale tests. It was found that normal distributions can be used as approximations to the statistical characteristics of the force amplitudes and periods. This paper addresses the determination of the distribution parameters. The random ice load function that is derived in this paper can be used in the dynamic analysis of compliant offshore structures with narrow ice breaking cones that are subjected to ice actions. Further limitations are discussed in the paper.