【作者】 潘小兵；

【导师】 任慧龙；

【作者基本信息】 哈尔滨工程大学 ， 船舶与海洋结构物设计制造， 2008， 硕士

【摘要】 随着海洋油气开采与运输事业的不断发展,作为目前最主要的油气输送工具,海底管道系统发挥着越来越重要的作用。由于海底管道处在恶劣的海洋环境中,承受着各种环境因素的影响,管道能否在营运期间安全运行引起了人们的广泛关注,因此对在役海底管道进行安全评估显得具有很强的现实意义。本文对海底管道安全评估工作的几个方面分别进行了研究。具体工作内容如下:1.研究了DNV OS F101中基于极限状态设计的海底管道可靠性设计方法以及分项系数法的基本原理,总结了用荷载抗力系数设计法（LRFD）进行管道结构强度设计的基本过程,并与基于工作应力（ASD）的CCS《海底管道系统规范》设计方法进行了比较。2.分析了海底管道悬跨段涡激振动形成机理及其特点。以悬跨振动控制方程,求解其固有频率。然后分别从静态和动态角度,以不同的标准推导出海底管道的允许悬跨长度。并将这些不同的方法与标准加以比较说明。3.基于现有的腐蚀海底管道爆破试验数据,选取国际上通用的ASME-B31G、DNV-RP-F101和PCORRC方法等评估腐蚀海底管道剩余强度方法,在失效压力计算公式、安全准则和失效标准等方面进行了对比分析。4.针对常用方法的保守性,以结构在全塑性状态时的参考应力的定义为基础,提出了确定腐蚀海底管道的极限载荷的参考应力法。应用ABAQUS有限元软件,进行了一系列含有不同腐蚀缺陷尺寸的有限元模型非线性分析。通过监测最小截面上的von Mises应力Oσ_local,确定了σ_local与施加的压力之间的关系。基于这种关系,提出了一种简单而又准确的确定腐蚀管道剩余强度的新方法。更多还原

【Abstract】 With the quick development of ocean oil gas exploitation and transportation, subsea pipeline system is playing a more and more vital role as the main means of transportation at present. Subsea pipelines are influenced by various environmental factors in the bad marine environment. Whether the pipelines can be safe in operation has been arousing people’s widespread interest. Therefore, the safety assessment for subsea pipeline in service appears very important.Several aspects of pipeline safety assessment work have been researched. The details are as follows:1. Subsea pipeline reliability design method based on limit state design and the basal principle of partial safety factor methodology in DNV OS F101 code are researched. The load and resistance factor design(LRFD) method and process for submarine pipeline strength design are summarized in comparison with CCS subsea pipeline system code which is based on allowable stress design(ASD).2. The vortex induced vibration (VIV) mechanism of pipeline free span and its characteristic are analyzed. The free span natural frequency is derived for the vibration governed equation. Then the allowable free span length is derived according to different standard, and from the view of static state and dynamic state. Then these approaches are compared with each other.3. Based on the corroded pipeline burst test data, the compared study of international general methods ASME-B31G, DNV-RP-F101 and PCORRC is carrier out in the aspect of failure pressure calculation formula, safety criterion and failure standard.4. In view of the commonly used method conservation, the reference stress approach to estimate the limit load of corroded pipeline is proposed based on the reference stress definition of the full plastic structure. Nonlinear finite element analyses of pipe containing different dimensional corrosive defects are carrier out by use of the ABAQUS finite element software. The relationship between the applied pressure and the von Mises stress in the minimum ligament is found. According to this relationship, an accurate and simple new method to estimate the residual strength of corroded pipeline is proposed.更多还原