Reducing modal truncation error in the wave response analysis of offshore structures
✍ Scribed by Léger, P. ;Ricles, J. M. ;Robayo, L. J.
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1990
- Tongue
- English
- Weight
- 564 KB
- Volume
- 6
- Category
- Article
- ISSN
- 0748-8025
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✦ Synopsis
The response of offshore structures subjected to wave loading is generally dominated by pseudo-static behaviour which is not efficiently expressed in truncated modal co-ordinates. In this paper, a new and efficient method has been developed to reduce modal truncation error in the numerical evaluation of transfer functions for the wave response of offshore structures. The solution is based on a transformation to a reduced system of generalized Ritz co-ordinates using load-dependent transformation vectors generated by a subspace iteration type of scheme from specified distributions of the dynamic loads. Numerical applications on a simple gravity platform model were used to establish systematic comparisons between the performance of the mode-displacement, the mode-acceleration and load-dependent solutions using various numbers of transformation vectors.