一种在役弯头半椭圆形裂纹的断裂评价方法  

A Fracture Evaluation Method for Semi Elliptical Crack of Elbow in Service

作　　者：罗华权 杨力能 李京川 王航 陈晓丽[2] Luo Huaquan;Yang Lineng;Li Jingchuan;Wang Hang;Chen Xiaoli(Tubular Goods Research Institute,CNPC(Xi’an,Shaanxi 710077,China);Research Institute of Oil and Gas Technology,PetroChina Changqing Oilfield Company(Xi’an,Shaanxi 710018,China))

机构地区：[1]中国石油集团石油管工程技术研究院,陕西西安710077 [2]中国石油长庆油田分公司油气工艺研究院,陕西西安710018

出　　处：《石油工业技术监督》2021年第4期20-23,共4页Technology Supervision in Petroleum Industry

摘　　要：通过对在役弯头的受力分析,把半椭圆裂纹模型应用于压裂弯头内表面裂纹型缺陷,并导出弯头内部半椭圆裂纹的应力强度因子计算公式。通过弹性断裂准则,可求得裂纹的深度或长度的安全允许值。分析结果表明:当裂纹深度值一定,裂纹长度增加,弯头内表面裂纹应力强度因子增加;且裂纹深度值越大时,裂纹长度增加时,其应力强度因子的增量越大。当裂纹长度值一定,裂纹深度增加时,弯头内表面裂纹应力强度因子增加;且裂纹深度值增量越大,其应力强度因子的增量越大。Based on the stress analysis of the elbow in service,the semi elliptical crack model is applied to the crack defect on the inner surface of the elbow,and the formula for calculating the stress intensity factor of the semi elliptical crack on the inner surface of the elbow is derived.The safe allowable value of crack depth or length can be obtained based on the elastic fracture criterion.The results show that:when the crack depth is fixed,the stress intensity factor of the elbow inner surface crack increases with the increase of crack length;the longer the crack is,the greater the increment of the stress intensity factor is.When the crack length is fixed,the stress intensity factor of the inner surface crack of the elbow increases with the increase of the crack depth;the greater the increment of the crack depth,the greater the increment of the stress intensity factor of the crack.

关 键 词：在役弯头 半椭圆形裂纹 弹性断裂 评价方法 

分 类 号：TE934.2[石油与天然气工程—石油机械设备]