Abstract
This paper aims to present an extended version of the classic linear wave excitation force theory. Linear wave theory implies that the wave load is applied in the referential state of the structure. In reality, the load is acting in the dynamically altered state. In the classic notation the wave excitation force is solely a function of time, hence the body is fixed in reference to the wave field. In this paper, the instantaneous position of the body is included in the calculation of the excitation force. Even though the displacement of the structure relative to a characteristic wavelength is generally small, it is demonstrated that the indicated nonlinear effect causes parametric instability at certain ratios between the wave frequency and the eigenfrequency of the structure. This calls for caution for structures designed to avoid resonance by having eigenfrequencies below the exciting wave frequencies.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of the Twenty-fifth (2015) International Ocean and Polar Engineering Conference |
| Number of pages | 5 |
| Publisher | International Society of Offshore & Polar Engineers |
| Publication date | 2015 |
| Pages | 1572-1576 |
| ISBN (Print) | 978-1-880653-89-0 |
| Publication status | Published - 2015 |
| Event | ISOPE: The 25th International Ocean and Polar Engineering Conference - Hawaii, Kona, Big Island, Hawaii, United States Duration: 21 Jun 2015 → 26 Jun 2015 Conference number: 25 |
Conference
| Conference | ISOPE |
|---|---|
| Number | 25 |
| Location | Hawaii |
| Country/Territory | United States |
| City | Kona, Big Island, Hawaii |
| Period | 21/06/2015 → 26/06/2015 |
Bibliographical note
Published on cd. Will also be published on ISOPES website after conference.Keywords
- Nonlinear wave excitation
- Stability analysis
- Parametric excitation
- Mathieu equation