摘要
油气管道裂纹评价的理论基础是断裂力学。在线弹性断裂力学中,应力强度因子(SIF)是判断油气管道裂纹是否将进入失稳扩展状态的重要指标。油气管道为金属材料,发生严格线弹性断裂的可能性不大,但只要塑性区尺寸远小于裂纹尺寸,经过适当修正,应用线弹性理论分析产生的误差可以接受。当塑性区尺寸与裂纹尺寸处于同一量级时,需要应用弹塑性理论,包括裂尖张开位移(COD)判据和J积分。可以采用应力强度因子、失效评价图及有限元方法评价油气管道裂纹的状态,有限元方法能够在一定程度上弥补其它2种方法在适用性方面存在的不足,但同时存在建模和计算效率较低,难以进行预防性评估的缺点。
Theory foundation of crack evaluation for oil & gas pipelines is fracture mechanics.In linear elasticity fracture mechanics, SlF is an important index to judge whether the cracks of oil & gas pipelines get into unstable progress state or not.Oil & gas pipelines are made from metal material,which is basically impossible to produce'strict'linear elasticity fracture,however,if the size of plastic zone is much less than that of crack,adopting linear elasticity theory to analyze the produced error will be acceptable after proper correction.When the size of plastic zone and the size of crack are in the same magnitude,linear elasticity theory is needed including COD criteria and J integral.In this case,stress strength factor,failure assessment block diagram and finite element method can be used to evaluate cracking state of oil & gas pipelines.Finite element method can cover the shortage of another 2 methods in applicability,but it has shortages in modeling and computing efficiency;and it is difficult to carry out a preventive evaluation.
出处
《油气储运》
CAS
北大核心
2010年第9期660-663,共4页
Oil & Gas Storage and Transportation
关键词
油气管道
裂纹
断裂力学
评价
有限元分析
oil & gas pipelines
crack
fracture mechanics
finite element analysis
evaluation
