复杂载荷条件下钻具接头台肩作用机理研究

摘要

To clarify the effects of the shoulder on the load bearing of connection threads,FEM models are built based onϕ139.7 mm FH connection under four conditions,i.e.no shoulder,only primary shoul-der,only secondary shoulder and double shoulders,respectively,and analyzed the mechanical properties under complex loads.Research results showed that the primary and secondary shoulders could play vital roles for ensuring the stability while making up connections;the primary shoulder can make the pin con-nection generating tensile effects under pre-tightening torsion,whereas the secondary shoulder can make the pin connection produce compressive pre-tightening effects,which,eventually,will affect the load bear-ing characteristics and ultimate torsion resistance.Under the same axial tension,the ultimate torsion re-sistance with only secondary shoulder is 12% higher than that when it has only primary shoulder,whereas the double-shoulder connection is 69% higher than when it has only a primary shoulder connection.Re-search results could provide references for development and the structure design of a new high-performance drilling tool connections.%为了解台肩对钻具接头螺纹牙承载的影响，基于ϕ139.7 mm 贯眼扣钻具接头分别建立了无台肩、仅主台肩、仅副台肩和双台肩等4种结构钻具接头的有限元计算模型，分析比较了其在复杂载荷作用下的力学特性和抗扭性能。分析结果表明：主、副台肩对保证钻具接头连接稳定性有着至关重要的作用；预紧扭矩作用下主台肩的存在使钻具接头公扣产生拉伸的预紧效果，副台肩的存在使钻具接头公扣产生压缩的预紧效果，从而直接影响了钻具接头的承载特征和极限抗扭能力；在相同轴向拉力的条件下，仅副台肩钻具接头的极限抗扭能力比仅主台肩钻具接头高约12%，双台肩钻具接头的极限抗扭能力比仅主台肩钻具接头高约69%。研究结果为新型高性能钻具接头的研发及结构设计提供了理论依据。