Ⅰ/Ⅲ复合加载模式下疲劳裂纹扩展曲线分析  

Analysis of Fatigue Crack Propagation under Ⅰ/Ⅲ Composite Loading Mode

作　　者：马佼佼[1,2] 许天旱[3] 杨继忠 梁航[1,2] 徐凯[1,2] 王一岑 宋红兵[1,2] 

机构地区：[1]国家石油天然气管材工程技术研究中心,陕西宝鸡721008 [2]宝鸡石油钢管有限责任公司,陕西宝鸡721008 [3]西安石油大学材料科学与工程学院,西安710065

出　　处：《焊管》2016年第5期12-16,24,共6页Welded Pipe and Tube

摘　　要：为了研究套管在钻井过程中的受力状况,以P110钻井套管用钢为对象,根据疲劳裂纹扩展理论,着重利用修正的紧凑拉伸试样,研究在I/III型分量下,不同裂纹倾角对材料疲劳裂纹扩展速率的影响。结果显示:当裂纹倾角为15°时,扩展过程中裂纹完全按照倾角15°扩展;当裂纹倾角为30°时,扩展过程中裂纹发生偏转没有实现完全30°扩展。研究表明,在复合疲劳裂纹扩展过程中,裂纹倾角越大,裂纹扩展方向越容易改变。The stress state of casing in the drilling process is extremely complex, taking drilling P110 well casing steel as the research object, according to the theory of fatigue crack propagation, using amended compact tension specimen, the effects on material fatigue crack propagation rate was studied under different crack angle. The results showed that when the crack angle is 15°, the cracks completely extend according to 15° in the process of the expansion; when the crack angle is 30°, crack deflection in the process of the expansion, did not achieve 30° extension. In composite fatigue crack propagation process, the greater the crack angle, crack extension direction change more easily.

关 键 词：焊管 套管 复合加载 疲劳裂纹扩展速率 应力强度因子 裂纹倾角 

分 类 号：TE973.1[石油与天然气工程—石油机械设备]