Characteristics of Frequency Response Function Obtained from Equation of Ship Roll Motion Including Nonlinear Restoration Term

• Published in: Journal of Fisheries Engineering Vol. 55; no. 3; pp. 187 - 192
• Main Authors: UENO, Kimihiko, HIDA, Yoshinobu
• Format: Journal Article
• Language: English
• Published: Hasaki The Japanese Society of Fisheries Engineering 01.01.2019; Japanese Society of Fisheries Engineering
• Subjects: Frequency; Frequency response function; Nonlinear equations; Nonlinear restoration term; Roll resonance; Ship motion; Ship roll motion
• ISSN: 0916-7617; 2189-7131
• DOI: 10.18903/fisheng.55.3_187

To perform the forced roll test using a model ship, it is necessary to accurately estimate the resonance frequency of the roll. If the restoring term of the equation of motion is linear, the frequency response function is a monovalent function. However, assuming that the restoring term is nonlinear, so that it becomes more realistic, the frequency response function becomes a multivalued function. In this study, this problem was overcome using a complete elliptic integral of the first kind.