Multi-modal fatigue in marine structures Seminar
- Time:
- 12:00 - 13:00
- Date:
- 26 November 2015
- Venue:
- University of Southampton Boldrewood Innovation Campus Building 176L, Room 1107
For more information regarding this seminar, please telephone Yeping Xiong on +44(0)23 8059 6619 or email Y.Xiong@soton.ac.uk .
Event details
Spectral fatigue or stochastic fatigue assessment procedure has long been the basis of fatigue prediction for ships and offshore structures. Size-up in terms of ships dimensions for recent decades has led to exposed to multi-modal fatigue damage increase due to springing and whipping vibrations. Meanwhile, station-keeping structures such as floating oil/gas platforms can be under multi-modal wave spectra composed of wave and swell excitations. Risers and mooring lines in floating offshore platforms with catenary mooring system inherently are subject to multi-modal tension loads. These multi-modal loads usually collapse, a critical assumption that response spectra are narrow-banded. The presentation includes an example of multi-modal spectrum in ship hull girder VBM which is caused by springing and whipping in 8100 TEU container carrier. A comparative study is presented to improve fatigue prediction accuracy due to the wide-bandness of spectrum.
Speaker information
Professor Joonmo Choung, INHA University, South Korea. Prof Choung has long been interested in how fracture damages initiate and propagate under accidental loads of marine structures such as ship-to-platform collision and platform explosion. He has also investigated dynamic flow stress variation according to the strain rates and temperatures. At present Prof Choung is trying to expand this background to ice technology such as fracture or spalling of the sea ice. His Secondary interest focuses on the wide band effect on accumulated fatigue damage of floating offshore plants (FPSO) and on the nonlinear fatigue due to contact, eg between LNG cargo tanks and supporting hull structures. His next topic is to design a mooring system for floating offshore wind turbines and offshore plants. His current research topics also include 1) development of elastic-plastic static-dynamic database of marine structural steels; 2) development of program to generate hydrodynamic and aerodynamic loads acting on very large sized offshore wind turbines; and 3) assessment of probabilistic residual strengths required.