摘要
在轴向、弯曲和扭矩等多种载荷的循环复合作用下,钻杆管体应力集中部位或材料缺陷处会产生裂纹萌生和疲劳裂纹扩展现象,导致管体失效甚至断裂。以API S135钢级钻杆管体为研究对象,通过单轴拉伸试验和裂纹扩展试验测试材料力学性能参数,建立管体数值仿真模型,并以管体疲劳失效案例作为验证对象来验证模型可行性。通过裂纹扩展数值模拟发现,管体内加厚过渡消失区最容易断裂失效,且载荷循环次数最低;载荷应力比增大,可以降低疲劳断裂失效风险。通过对管体内加厚过渡消失区结构改进设计发现:改进管体内加厚锥部长度和管体外加厚锥部长度对管体最大应力和载荷循环次数改变不大,而提高管体壁厚t后应力下降显著,且载荷循环次数提高明显。因此提高管体壁厚t是更为有效的改进方式,并通过正交实验对结构组合进行分析和优选。
Under the cyclic compound action of multiple loads,such as axial,bending and torque loads,crack initiation and fatigue crack propagation occur at the stress concentration position or defect of the pipe body,and lead to failure or even fracture of the pipe body.The API S135 steel drill pipe body was taken as the research object,the mechanical properties of the material were tested by using the uniaxial tensile test and crack propagation test,the simulation model for the drill pipe body was established,and the fatigue failure cases of API S135 steel grade drill pipe were taken as the object to verify the feasibility of the simulation model.Through the numerical simulation of crack propagation,it is found that the thickening transition zone inside the pipe body is the most prone to fracture failure,and the load cycle times are the lowest.The increase in load stress ratio can reduce the risk of fatigue fracture.The conclusions are obtained that by improving the structural design of the thickening transition zone in the drill pipe body:the maximum Mises stress and the number of load cycles are slightly affected by modifying the inside and outside thickening cone lengths,the Mises stress decreases significantly and the number of load cycles increases significantly after increasing wall thickness of the drill pipe body,therefore,increasing wall thickness of the drill pipe body is a more effective improved method,and the structural combination is analyzed and optimized by using the orthogonal experiment.
作者
费根胜
王从奎
曾宪林
唐穗欣
张义
FEI Gensheng;WANG Congkui;ZENG Xianlin;TANG Suixin;ZHANG Yi(Department of Automation Artificial Intelligence School,Wuchang University of Technology,Wuhan 430223,China;Chuanxi Drilling Company,CNPC Chuanqing Drilling Engineering Company Limited Co.,Ltd.,Chengdu 610051,China)
出处
《机械科学与技术》
CSCD
北大核心
2023年第10期1638-1647,共10页
Mechanical Science and Technology for Aerospace Engineering
基金
重庆市教育委员会科学技术研究项目项目(KJQN201901332)。
关键词
钻杆管体
复合载荷
裂纹扩展
结构改进
数值仿真
drill pipe body
composite load
crack propagation
structure improvement
numerical simulation
