Fracture mechanics in fatigue calculations as the assistance in structural design. Case study |
| |
Affiliation: | 1. Allseas Engineering bv, Poortweg 12, 2612 PA Delft, The Netherlands;2. Fairlead Maritime, Unit 45 Riverside Building, Trinity Buoy Wharf, Orchard Place, London E14 0JW, United Kingdom;1. Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Science, Changchun, Jilin 130031, China;2. University of Chinese Academy of Science, Beijing 100039, China;1. Mahatma Gandhi Institute of Technology, Hyderabad 500075, India;2. Defence Metallurgical Research Laboratory, Hyderabad 500058, India;3. School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046, India;1. Multiscale Materials Modeling Lab, Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR, USA;2. Institute for Nanoscience and Engineering, 731 W. Dickson Street, University of Arkansas, Fayetteville, AR 72701, USA;1. CAS Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;2. University of Chinese Academy of Science, Beijing 100049, China;3. Open Studio for Marine Corrosion and Protection, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China;4. Center for Ocean Mega-Science, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China;5. School of Municipal and Environment Engineering, Harbin Institute of Technology, Harbin 150090, China;6. State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China;7. Federal Institute for Materials Research and Testing, D-12205, Berlin, Germany |
| |
Abstract: | A case study originated from a request to perform fatigue calculations on a partial penetration weld in a steel casting on a new heavy lift ship. The ship has a special lifting system for lifting and transporting topsides of offshore oil/gas platforms. There are many sizes of offshore platforms so the lift system is designed to move along the vessel on rails, which are part of the main deck of the ship hull. The loads passing into the rails during lift operations are large, and massive steel castings of complex shapes are used to distribute these loads into the hull. The castings are very thick so it is difficult to achieve full penetration welds, and therefore the initial design proposed partial penetration welds. In order to decide if the partial penetration welds were adequate, a fatigue assessment was carried out using a fracture mechanics approach based on BS7910. Different possibilities of the bevelling of castings edges in preparation for welding were considered in the stress analysis and in the crack growth estimations. In the areas of the ship hull which experienced high dynamic stress ranges none of the different possibilities showed acceptable fatigue life, and would demand re-design. The stress intensity factors obtained through the extensive finite element analysis were compared with the analytical solutions available in literature. Both results showed good correspondence. |
| |
Keywords: | Fatigue assessment Fracture mechanics Stress intensity factors Design |
本文献已被 ScienceDirect 等数据库收录! |
|