Fatigue Performance of Grade R4 and R5 Mooring Chains in Seawater
Fatigue Performance of Grade R4 and R5 Mooring Chains in Seawater
复制标题
R4和R5级系泊链在海水中的疲劳性能
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
J. Navas
中科院分区：
文献类型：
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作者：
Jonathan Fernández;W. Storesund;J. Navas
到目前为止，石油和天然气行业已经有超过50,000吨的服务，需要了解R5级链在直张力下的拉伸疲劳性能，并证实现有设计方法的有效性。API和DNV的链条疲劳设计曲线是基于90年代和2000年代初获得的疲劳试验。然而，测试是在ORQ、R3和R4等较低等级和小链上进行的，76毫米直径是测试的最大无螺柱链。该行业已经转向使用大型无螺柱链，特别是在永久装置中，链条直径超过150毫米并不罕见。本文收集了R4级和R5级无螺柱链的全尺寸疲劳试验程序的信息，该试验在海水中进行，直径在70毫米到171毫米之间。正在测试的链条是为不同钻井装置和大型永久系泊生产浮式装置提供的实际生产链。本文在不考虑其他损伤机制的情况下，根据API和DNV方法计算累积疲劳损伤，对数据进行分析，确定拉伸-拉伸疲劳曲线。相对于上述推荐的设计方法，得到了改进的疲劳能力。ASME版权所有©2014
With more than 50.000 tons in service to date, the Oil&Gas Industry has the need to understand the tension fatigue performance of grade R5 chains in straight tension, and corroborate the validity of the existing design methods.The chain fatigue design curves in API and DNV are based on fatigue tests obtained in the nineties and early two thousands. However the tests were performed on lower grades such as ORQ, R3 and R4, and small chains, 76 mm diameter being the largest studless chain tested.The industry has moved towards the use of large studless chains, especially in permanent units, where chain diameters above 150 mm are not unusual.This paper gathers information from a full scale fatigue test program on grade R4 and R5 studless chains, performed in seawater and with diameters between 70 mm and 171 mm. The chains being tested are actual production chains supplied for different drilling units and large permanently moored production floating units.The paper analyses the data and determines tension-tension fatigue curves based on API and DNV methods for computation of cumulative fatigue damage, regardless of other damaging mechanisms. Improved fatigue capacity is obtained with respect to the above recommended design methods.Copyright © 2014 by ASME