关键词: 石油钻杆, 螺纹接头, 表面裂纹, 应力强度因子, 三维有限元

Abstract: This is Paper One in a series of articles on the three-dimensional FEM analysis of stress-intensity factor in petroleum drill pipe joint with surface crack,in which is given a basic calculation fqrmula fob a solution to the surface crack by three-dimensional FEM displacement methods.Quite a few calculation examples show that the solution used in this paper can fairly accurately present the regularity of change in the stress-intensity factor along the leading edge.And Moreover,here is presented a simplified model for petroleum drill pipe joint screw-thread connection.The regular distribution in the load along the screw insection is reasonably stimulated.