Session: 02-14-03 Structural Analysis of Marine Structures 3

Submission Number: 182270

Numerical Simulation of Laboratory Rigid Impact Experiments on Non-Ice Class Ship Hull Structures 

Arctic sea ice is retreating and thinning at an increasing rate year after year. Shipping without icebreaker support is becoming more prevalent for longer periods of the year in some parts of the Arctic. Still, even in areas with low ice concentration, risks of collisions with small ice floes are and will be significant. Thus, assessing the structural reliability of low- and non-ice class ships both numerically and experimentally is a matter of importance. With this in mind, several impact tests using a large double pendulum apparatus were conducted at Memorial University of Newfoundland between March and August of 2025. These impacts tested the performance of non-ice classed ship structure grillages made of EH36 grade steel against a variety of large rigid and ice indenters. This paper focuses on the testing of one grillage structure subject to two repeated impacts by a rigid smooth indenter and one impact by a large ice cone indenter. It highlights the experimental results while focusing on the development of a representative non-linear finite element numerical model of the grillage structure. The maximum impact energy recorded was more than 40kJ, resulting in a maximum force of 900kN. The rigid indenter caused the shell plate to deform more than 70mm, while the ice indenter caused a deformation of just over 60mm. The material characterization of the steel was completed with results from uniaxial tensile tests. Results from the numerical analysis show fair agreement with the respective experimental data, illustrating the post-yield plastic behaviour of the EH36 grillage structure.

Presenting Author: Zachary Greenham Memorial University of Newfoundland

Presenting Author Biography: Zachary Greenham graduated from Memorial University's Ocean and Naval Architecture program in 2024. He is now completing a Master of Engineering in ONAE at MUN, focusing on ship-ice interactions. Specifically, his research is on the performance of ship structure of low- and non-ice class ships operating in marginal ice zones in the Arctic.

Authors:

Zachary Greenham Memorial University of Newfoundland
Bruce Quinton Memorial University of Newfoundland
Sthefano Andrade Memorial University of Newfoundland