Methods for removing inertial force from measured wave impact force signals

• Main Author: Winsor, Fraser N., 1961-
• Other Authors: Memorial University of Newfoundland. Faculty of Engineering and Applied Science
• Format: Thesis
• Language: English
• Published: 2000
• Subjects: Wave resistance (Hydrodynamics); Offshore structures > Hydrodynamics; Newfoundland studies; University of Newfoundland
• Online Access: http://collections.mun.ca/cdm/ref/collection/theses3/id/125025

Thesis (M.Eng.)--Memorial University of Newfoundland, 2000. Engineering and Applied Science Bibliography: leaves [194-197] This report discusses the implementation of three methods for removing or mitigating the so-called inertial force from measured signals resulting from wave impact on components of offshore structure models. The wave impact causes vibration or acceleration in the modeted component. The acceleration is perceived as a force by the measurement transducers. This inertial force component is not scaleable, and must be removed in order to obtain the actual applied force. -- A mitigation method based on the solution of the system equation of motion using normalized coordinates, known as the normal mode method, is investigated. A technique based on the division of the fast Fourier transform of the measured force by the system frequency response, known as the inverse Fourier transform method, is implemented. Finally, the use of digital low pass and band reject filters is examined. -- These techniques are applied to wave impact and decay test measurements from experiments conducted on jacket type fixed offshore structure models. -- The results prove to be less than ideal. The reasons for this are discussed, and recommendations are made for future investigations.