TY - JOUR

T1 - Time‐Domain Implementation and Analyses of Multi‐Motion Modes of Floating Structures

AU - Sheng, Wanan

AU - Tapoglou, Evdokia

AU - Ma, Xiandong

AU - Taylor, C. James

AU - Dorrell, Robert M.

AU - Parsons, Daniel R.

AU - Aggidis, George

PY - 2022/5/13

Y1 - 2022/5/13

N2 - The study of wave‐structure interactions involving nonlinear forces would often make use of the popular hybrid frequency–time domain method. In the hybrid method, the frequency‐domain analysis could firstly provide the reliable and accurate dynamic parameters and responses; then these parameters and responses are transformed to the parameters to establishing the basic time domain equation. Additionally, with the addition of the required linear and nonlinear forces, the time‐domain analysis can be used to solve for the practical problems. However, the transformation from the frequency domain to the time domain is not straightforward, and the implementation of the time‐domain equation could become increasingly complicated when different modes of motion are coupled. This research presents a systematic introduction on how to implement the time‐domain analysis for floating structures, including the parameter transformations from the frequency domain to the time domain, and the methods for calculating and approximating the impulse functions and the fluid‐memory effects, with special attention being paid to the coupling terms among the different motion modes, and the correctness of the time‐domain‐equation implementation. The main purpose of this article is to provide relevant information for those who wish to build their own time‐domain analyses with the open‐source hydrodynamic analysis packages, although commercial packages are available for time‐domain analyses.

AB - The study of wave‐structure interactions involving nonlinear forces would often make use of the popular hybrid frequency–time domain method. In the hybrid method, the frequency‐domain analysis could firstly provide the reliable and accurate dynamic parameters and responses; then these parameters and responses are transformed to the parameters to establishing the basic time domain equation. Additionally, with the addition of the required linear and nonlinear forces, the time‐domain analysis can be used to solve for the practical problems. However, the transformation from the frequency domain to the time domain is not straightforward, and the implementation of the time‐domain equation could become increasingly complicated when different modes of motion are coupled. This research presents a systematic introduction on how to implement the time‐domain analysis for floating structures, including the parameter transformations from the frequency domain to the time domain, and the methods for calculating and approximating the impulse functions and the fluid‐memory effects, with special attention being paid to the coupling terms among the different motion modes, and the correctness of the time‐domain‐equation implementation. The main purpose of this article is to provide relevant information for those who wish to build their own time‐domain analyses with the open‐source hydrodynamic analysis packages, although commercial packages are available for time‐domain analyses.

KW - frequency domain analysis

KW - Time domain analysis

KW - hybrid frequency-time domain method

KW - impulse function

KW - memory effect

KW - prony approximation

U2 - 10.3390/jmse10050662

DO - 10.3390/jmse10050662

M3 - Journal article

VL - 10

JO - Journal of Marine Science and Engineering (JMSE)

JF - Journal of Marine Science and Engineering (JMSE)

SN - 2077-1312

IS - 5

M1 - 662

ER -