Session: 05-01-01 New Concept and Marine Environment for OSU

Submission Number: 157161

Experimental Research on Nonlinear Deflection Wave of the Floating Plate 

In this research, the nonlinear wave beneath a 2D floating plate, representing a prototype Very Large Floating Structure (VLFS), is investigated. This special nonlinear phenomenon, arising from fluid-structure interaction, is referred to in this paper as the nonlinear deflection wave. First, the theoretical solution of the nonlinear deflection wave, which shares similarities with the conventional Stokes Wave Theory, is introduced. Based on the theoretical solution, the resonance period associated with the second-order response is identified, revealing significant differences compared to the conventional Stokes Wave Theory.

To validate the theoretical solutions, a model test is designed and conducted in a two-dimensional water tank. The elastic model is constructed using closed-cell rubber foam, with a total length of 10 meters. Three types of responses, displacement, acceleration, and strain are measured simultaneously to ensure accurate data collection. Measurements are taken at multiple positions along the floating plate to examine variations in the second-order responses at different locations. Particular emphasis is placed on the central area, where densely arranged strain gauges are deployed. A series of regular wave tests with varying wave periods is conducted, with the wave periods selected near the resonance period predicted by the theoretical solutions to more clearly generate the nonlinear deflection wave.

In this paper, the model test is primarily demonstrated, followed by a discussion of the test results, with a focus on the second-order response. The resonance period predicted by the theoretical solutions is successfully validated through the model test. Additionally, the phase-reversing behavior anticipated by the theoretical solutions is also observed during the model test. Furthermore, based on the model test results, the existence of the nonlinear deflection wave phenomenon, attributed to fluid-structure interaction and predicted by theoretical derivation, is finally verified.

Presenting Author: Chong Ma National Maritime Research Institute

Presenting Author Biography: The author is currently working as a Senior Researcher at the National Maritime Research Institute, Japan. His main research interests include fluid-structure interaction, nonlinear phenomena of VLFS, sloshing, smoothed particle hydrodynamics, and ship hull monitoring techniques.