螺纹参数公差对油管螺纹连接强度的影响分析

用弹塑性有限元法建立了圆螺纹油管接头接触问题的有限元模型,利用ANSYS大型有限元分析软件,对不同油管螺纹参数偏差的油管接头机紧连接和承受拉伸载荷作用工况的应力应变进行了数值计算。计算结果分析表明,油管各螺纹参数偏差不改变油管发生强度破坏的螺纹牙齿位置;不同的螺纹参数偏差对油管螺纹的连接强度影响不同,螺距公差、牙型角上偏差及齿根高下偏差对油管螺纹连接强度的影响较大。给出了各螺纹参数偏差对油管螺纹连接强度影响程度的排序,为油管螺纹的质量检测和油管断裂失效分析提供了一定的理论依据。

Analysis of effect of thread parameter tolerances on connecting strength of tubing threads

The finite element models for contact problems of round threaded tubular joints are established with the elasto-plastic FEM. By means of large finite element analysis software ANSYS, the stress and strain fields of tubular joints with errors of five kinds of tubing thread parameters are calculated under different tensile loads applied on tubing. The result shows that thread parameters errors don't change the tooth place of strength failure of tubing thread. Each kind of thread parameters errors can make different effect on the connectingstrength of tubing thread. Also, pitch tolerances, positive error of tooth form angle and negative error of tooth root height will weaken the connecting strength of tubing thread much more. The order of affecting degree of thread parameters tolerances on connecting strength of round threaded rubing is presented. The research provides a theoretical support for the quality inspection of tubing thread and investigating fracture failure of round threaded tubing.