Indexed by:Journal Article

Date of Publication:2018-03-01

Journal:APPLIED OCEAN RESEARCH

Included Journals:Scopus、EI、SCIE

Volume:72

Page Number:23-38

ISSN:0141-1187

Key Words:Dynamic characteristics analysis; Nonlinear offshore jacket platform; Sea-ice excitation; Non-stationary environmental load; Long-time monitoring; Acceleration response

Abstract:This paper proposes a method to structurally identify inherent dynamic characteristics based on long-term monitored acceleration data of nonlinear offshore platforms under sea-ice excitation. Not all the inherent characteristics can be excited due to the randomness of ice loading and its limited bandwidth. However, the long-term monitored data can reflect most of the conditions of sea-ice excitation. The change of natural characteristics of the platform under ice loads can be identified by analyzing of long-term monitored data. A nonlinear system of two-degree-of-freedom (2DOF) is simulated to identify dynamic characteristics and verify the effectiveness of the proposed method. The method is applied to analyze the acceleration data caused by ice-induction at a jacket platform in Liaodong Bay. The inherent characteristics of the structure can be identified and its variation under different ice-load intensities is summarized. (C) 2017 Elsevier Ltd. All rights reserved.