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Lookup NU author(s): Professor Zhiqiang Hu
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0).
This paper proposes a nonlinear viscoelastic iceberg material model. A nonlinear Burgers’ model in which Kelvin and Maxwell units are strain rate- and stress-dependent is adopted for the iceberg material. The strain rate effect is considered in this model based on the experimental results. The stress of the iceberg model grows linearly (in log form) with increasing strain rate before reaching the transition strain rate, after which the stress remains rather constant. A damage function that reflects microstructure changes and severe fractures in ice is adopted as the failure criterion. The iceberg model is implemented using implicit integration Crank-Nicolson method and is incorporated in the commercial software LS-DYNA by a user-defined material. Laboratory-scale experiments, creep experiments and constant strain rate experiments, and reality-scale experiment, iceberg–rigid steel plate collisions, are simulated to validate the proposed iceberg material model. Simulated time–strain curves are compared with the results of creep experiments. In the constant strain rate experiments, the strain–stress curves for brittle and ductile failure and ultimate triaxial strength of the ice model are analysed. Area–pressure curves and contact force–displacement relations are investigated for different impact speeds in iceberg–steel plate collisions. Contact force is also studied in view of the kinetic energy of icebergs. The numerical results show that the proposed iceberg material model yields reasonably good results.
Author(s): Shi C, Hu Z, Ringsberg J, Luo Y
Publication type: Article
Publication status: Published
Journal: Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment
Online publication date: 07/12/2016
Acceptance date: 20/10/2016
Date deposited: 03/02/2017
ISSN (print): 14750902
ISSN (electronic): 20413084
Publisher: SAGE Publishing Ltd
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