Investigations on Springing and Fatigue Damage of Ship Structures Seminar
For more information regarding this seminar, please telephone Dr Yeping Xiong on +44 (0)23 80596619 or email Y.Xiong@soton.ac.uk .
Event details
Springing is a hull-girder resonance phenomenon, which is induced by continuous promoting of exciting waves. It is different from whipping caused by instantaneous wave impact. Large ships will suffer from severe springing vibrations even in low and medium sea states, because the encounter wave frequencies may coincide with the natural frequencies of ship structure. It makes the existence of ship structure stress with high frequencies, continuous vibrations and certain amplitudes. Thus the serious fatigue damage may appear in ship structures.
Systemic and embedded investigations on springing and fatigue damage of large ship structures were carried out in CSSRC. It contains the theoretical and experimental investigation of an ultra large 300,000 DWT oil tank, an ultra large 500,000 DWT ore carrier and a large 156,800 m3 LNG carrier. In this paper, three dimensional hydroelastic theories are used to predict springing responses of large ships. Experimental investigation of springing is carried out with models considering different body-lines, damping ratios, hull girder stiffness and loading conditions. And the fatigue damage are analyzed and evaluated according to the springing phenomena. Modified formula of design fatigue wave loads including springing effects was recommended based on the fatigue damage evaluating method of CCS rules. Based on theoretical investigations, a new ship form with deep draft bodylines was recommended for large ship design, which can greatly restrain hull girder springing responses and reduce fatigue damage.
Speaker information
Dr Xueliang Wang , Senior Engineer and Deputy Head of Water Surface Research Group from China Ship Scientific Research Center (CSSRC).. He obtained a Coastal and Ocean Engineering bachelor in 1999 from Hohai University in Nanjing China. He spent 4 year as an assistant engineer in fluid department in CSSRC. He got his master and PhD degree in Naval Architecture and Ocean Engineering from CSSRC in 2006 and 2012, respectively. Since 2009, he has been a senior engineer and deputy head of water surface group in research department of ship structure in CSSRC. He has joined many key projects including LNG, ULOC, VLCC, BC and Semi-submersible drilling platform from MIIT, CSNAME and CCS. He had published about twenty journal and conference papers, ten patents and six software copyrights in China since 2006. He had won the Jiangsu provincial science and technology progress award in 2011 and the CSIC science and technology progress award in 2009. Now he is an academic visitor in FSI group of FEE in the University of Southampton. His main research area is focus on: 1) Theoretical and experimental investigation of wave loads; 2) Full scale testing technology of hull strength.