1C5 75.180.10
E 92
备 容 号 竺 14096- 2004
中华人 民共和国石油天然气行 业标准
SY/T 10049-2004
海上钢结构疲劳强度分析推荐作法
Reconunended practice for fatigue strength analysis
of offshore steel structures
(DNV RP一C203: 2001,IDT)
2004一07-03发布
2004-11-01实施
国家发展和改革委员会
发 布
SY/T 10049- 2004
目
次
前言 ··········································,··································································…… m
DNV前言 ···········································································································…… A'
致 谢 ···················································································,······························…… V
变更 ···········································································································…… Vl
1 引言 ···········,··················································,···············································…… 1
1.1 总则 ········,···································································································…… 1
1.2 标 准的有效性 ·······················,··········································,················...·······.…… 1
1.3 疲 劳分析方法 ··························································...········....... ·.............…… 1
1.4关于省略详细疲劳分析的指南·····························································……““”‘””1
1.5 符 号 ····························································································,·····,·········…… 1
2 基于疲劳试验的疲劳分析 ··········································································,········一 3
2.1 引言 ······。·····································································,············,················…… 3
2.2 需 要考虑的应力 ,·······················································,······.··········......···........… … 3
2.3 S - N 曲线 ····································································,···························…… 4
2.4 非焊接结构平均应力的影响 ······································································……““’‘’‘9
2.5 制造公差的影响 ·····················································,···············.……,··............… … ,
2.6 板件结构的应力集中系数 ·····················································,······················……”’“9
2.7 船舶细部的应力集中系数·································································,···········……““12
2.8 管节点及构件的应力集中系数··········································,·············.......·........…… 12
2.9 方形截面节点的应力集中系数··········································································…… 18
2.10 角焊缝及部分熔透焊缝 ··········································································,···,·…… 18
2.11 螺栓 ········,············································································,·················…… 19
2.12 管线 ···················,··················································································…… 19
2.13 用有限元分析法计算热点应力 ·······································································…… 20
2.14 疲劳的简化分析 ····························································,·················,·..······…… 22
3 基于断裂力学的疲劳分析··················································································…… 26
3. 1 引言 ··········································································································,··… 26
4 通过制造提高疲劳寿命·················································,············...................… … 27
4. 1 总则 ·································································································,·······…… 27
4.2 通过机加工 和打磨进行焊缝外 观处 理·································································…… 27
4.3 打磨 ···,···································································,······。·························…… 28
4.4 钨极惰性气体保 护焊 CTIG)表 面处理 ······························································…… 28
4.5 锤击 ········································································································…… 28
5 延长的疲劳寿命···························································································.·…… 29
6 疲劳寿命预测中的不确定性··································,································,···········…… 29
6.1 总则 ·························································································,·················… … 29
7 参考文献 ···,····················,··············································································…… 30
附 录 A (规范性附录 ) 构造细部 的分类 ·····························································,…… 33
T
SY/T 10049- 2004
附录 B (规范性附 录) 管节点 的应力集 中系数 ,·····… …
附录C (规范性附录) 板开孔加强处的应力集中系数··…
附录 D (规 范性附录) 注释 ··················-·············… …
一一
SY/T 10049- 2004
前
言
本标准等同采用挪威船级社 (DNV) 《海上钢结构疲劳强度分析推荐作法》(DNV RP一C203,
2001年10月版,英文版),作为中华人民共和国石油天然气行业推荐标准。
本标准等同翻译 DNV RP一C203 Fatigue strength analysis of offshore steel structures, October
2001。如对本标准的译文有疑义,以采用本标准的原文为准。
在中华人 民共 和国领海 内,海洋石油 、天然气开发工程设计 、建造和使用中涉及原标准所在 国政
府 或其他主管部 门的法令 、法规和规定 时 ,一律按 中华人 民共和 国政府或 主管部 门颁 布的相 应法令 、
法 规和规定执行 。
本标准 中计量单 位以法定单位 为主,即法定单位在 前 ,英制单 位的相应 数值置 于其后 的括号 内。
为不改变原公式、曲线的形状特征、常数和系数,凡使用英制单位,仍沿用英制单位。
本标准 的附录 A、附录 B、附录 C、附录 D均为规范性 附录。
本标准由海洋石油工程专业标准化委员会提出并归口管理。
本标准起草单位:中油辽河工程有限公司。
水标准卞要R草人,刘丹、仟润卯、李旭志、庞秀英、终光军、裴红、康荣玉、杜凯秋、何廷会。
SY/T 10049- 2004
DNV 前 言
挪威船 级社 (DNV)是一个 旨在保 护海 上及 岸上 生命 、财产 以及环 境的安 全 的独立 自主机 构 ,
承担有关船舶、海上装置与设备以及世界各地岸上工业的人级、认证以及其质量的检验及咨询服务,
并进行相关 研究。
挪威 船级社的海上 出版物包括 三级文件 :
— 海上服务规范 :提供挪威 船级社的人级 、认证 、检验及咨询服务 的原则 和程序 。
— 海 上标准 :提供海洋行业 通用的技术规定 及验 收标准 以及挪威船 级社海上服务 的技术基础 。
一一 推荐作法:提供成熟的技术、可靠的工程实用方法以及更高级别的海上服务规范及海上标准
指南。
挪威船 级社海上出版物所涉 及的领域包括 :
a)质量及安全方法 ;
b)材料技 术 ;
c)结构 ;
d)系统 ;
e)专用设施 ;
f)管线及立 管 ;
9)资产的运营。
SY门 10049- 2004
致
谢
该推荐作法 的编 写得到了一些海上行业 、研究院所 以及大学 的密切 合作 ,在此对于他们所做 的贡
献深 表感谢 。
SY/T 10049- 2004
变
更
主要 变更 如下 :
在对 接焊缝 及交叉节点 的应力 集中系数 (SCF)计算 中,轴偏量 可以减去 S-N 曲线 中的固有值
在有焊缝外观处理的情况下,折减热点应力的计算公式为式 ((4.2.3)
SY/T 10049- 2004
海上钢结构疲劳强度分析推荐作法
引 言
1. 1 总则
本推荐作法 是以疲劳试验 和断裂力学为基础提 出的有关疲 劳分析的建议 。推荐 作法 的适用条件见
下文的 1.2
进行疲劳设计的目的是确保结构具有满足要求的疲劳寿命。通过计算得出的疲劳寿命也是在结构
制造和使用过程中实施有效检验工法的依据。
为 了确保 结构实现预定 的功能 ,应对承受疲劳荷 载的每一个单独构件进行疲 劳评估 ,在适 当的情
况下要进行详细疲劳分析,参见 1.4。应注意的是任何结构单元或构件,每一焊接节点及焊接附件,
或者任何形式 的应力集 中都是潜 在的疲劳裂纹源 ,因而应单独考虑 。
1.2 标准的有效性
本推荐作法适用于大气中屈服强度小于 700 MPa的钢材,海水中有阴极保护或自由腐蚀且屈服
强度不 高于 500 MPa的钢 材。
本 推荐作法还适用于 大气环境中或防护 等级达 到 ASTM A490或 等同标 准中 10.9级 条件 的螺 栓
本 推荐 作法可适用于不 锈钢。
1.3 疲劳分析方 法
疲 劳分析应建立在 5一 N 数据和线性损伤假设基 础上 ,而 S-N 数据是通过对所考虑 的焊接细部
进行疲劳试验得出的。在适当的情况下,疲劳分析也可建立在断裂力学基础上。对于失效后会导致严
重后果的构件,如果基于疲劳试验的疲劳寿命评估不够充分时,应对结构进行更大范围的更精确调查
研究 ,或进行断裂力学分 析。在断裂力学基 础上进行的计算应证 明在在役检 验过程中检测 出裂纹 出现
的时间和失稳断裂之 间的时间间隔是足够 的。
对于可能影响结构疲劳损伤的所有有效应力幅都应予以考虑。通过确定性分析或者谱分析可得出
应力幅的长期分布,参见参考文献 [1]。在确定应力历程时,应对动力效应给予充分的说明。疲劳分
析 可建立在期望 的应力 历程基础上 ,应力 历程可定义为 预期 寿命 内每个应力 幅水平 的预计循环 次数 。
在实际应用中就是确定偏于安全的长期应力幅历程。对疲劳损伤产生重要影响的那部分应力幅历程应
给予足够的评估。相关指南请参见附录D 《注释》。
应说明的是 Weibull分布中的形状参数 h对于计算疲劳损伤具有很大的影响。有关形状参数对疲
劳损伤的影响参见图2. 14一1和图2. 14一2中的设计图表。因此,当按照以 Weibull长期应力幅分布
为前提的闭型解计 算疲 劳损伤时 ,应使 用偏于安全 的形状参数 。
1.4 关于省略详细疲劳分析的指南
按照式 ((2.2.1)确定 的实际细部的最大局部应力 幅小于表 2.3一t(适 用于大气 中)和表2,3一2
(适用于海水中并有阴极保护)中 107次循环所分别对应的疲劳极限,则可省略详细疲劳分析。在设
计疲劳系数大于 1时,还应把此处的容许疲劳极限乘以系数 (DFF)-assn DFF,的定义见 OS一C101
参考文献 [28二。
对详细疲 劳分析的要求 ,也 可根 据图 2.14一1和 图 2.14一2中的疲劳评估 曲线确定 。
1.5 符 号
C
D
材料参数
累积疲劳损伤,弦杆直径