A Laplace-domain method for motion response estimation of floating structures based on a combination of generalised transfer function and partial fraction. (13th September 2020)

• Record Type: Journal Article
• Authors: Liu, Fushun; Fu, Qiang; Tian, Zhe
• Is Part Of: Ships and offshore structures. Volume 15:Number 8(2020)
• Page Start: 829
• Page End: 843
• Publication Date: 2020-09-13
• Subjects: Laplace-domain response -- floating structure -- transfer function -- Fourier transform -- SESAM; Ships -- Periodicals; Offshore structures -- Periodicals; Marine engineering -- Periodicals; Marine engineering -- Technological innovations -- Periodicals; Ocean engineering -- Periodicals; Ocean engineering -- Technological innovations -- Periodicals; 623.8
• DOI: 10.1080/17445302.2019.1687145
• Languages: English
• ISSNs: 1744-5302

Abstract

ABSTRACT: A Laplace-domain method is proposed to predict time-domain motion responses of floating structures. As a theoretical contribution, two techniques of generalising transfer functions of floating structures (GTFF) are developed, which are symbolic-based and Fourier transform-based techniques. Three cases are employed in this study: The first case involves a single degree-of-freedom system to demonstrate the correctness of the derived GTFF, which is assumed to have a purely analytical retardation function. The second case involves a truncated cylinder subjected to random waves that are defined by a Jonswap spectrum. Numerical results show that the symbolic approach simultaneously offers a perfect estimation of the transfer functions of a system, while the inverse Fourier-transform-based approach has some discrepancies at the first short parts of the phases. To further investigate potential applications, a floating platform is employed, and comparisons are drawn by using the commercial software SESAM, which found consistently estimated motion responses.