Evaluation of methods to remove inertial force from measured model wave impact force signals

  1. Get@NRC: Evaluation of methods to remove inertial force from measured model wave impact force signals (Opens in a new window)
DOIResolve DOI: http://doi.org/10.1016/S0029-8018(02)00012-4
AuthorSearch for:
Journal titleOcean Engineering
Pages2484; # of pages: 61
SubjectOffshore structure; Jacket structure; Inertial force; Normal mode; Inverse Fourier transform; Filters
AbstractThe subject of wave impact on offshore structures and their components is important to vessel designers and operators for many reasons. They are often required to quantify these impact loads. Standard methods for wave load prediction will underestimate the forces on these structures due to intermittent loading. This necessitates the use of physical model tests to establish wave impact loads. The model measurement systems are designed to have high stiffness. This ensures that the natural frequency of the structure is above the wave frequency. However, it is widely believed that impacting waves contain high-frequency energy components that cause the structure to vibrate at its modal frequencies. This impact-induced vibration is recorded by the measuring system as a force (inertial force), and corrupts the actual applied force measurement. Before scaling can occur, the inertial force must be removed from the measured signal. A number of techniques for removing inertial force from measured signals are described in the published literature. Three methods are discussed, implemented and compared in this paper. The algorithms and procedures are presented. Each technique contains inherent and unique problems, while some are common to all methods. Neither of the techniques produced results that are fully satisfactory. The main problem is unwanted high-frequency content after the application of the methods. While neither method offers the perfect solution, the use of digital filtering techniques is recommended based on their relative performance and ease of implementation.
Publication date
AffiliationNRC Institute for Ocean Technology; National Research Council Canada
Peer reviewedYes
NRC number6346
NPARC number8895221
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Record identifier81b08624-c2da-4dd6-8311-09384997a37e
Record created2009-04-22
Record modified2016-05-09
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