过扭与欠扭工况下特殊螺纹油管接头三维有限元分析

摘要

Considering the helix angle,the elasto-plastic contact FEM was used,and ABAQUS FEM was used to establish three-dimensional model for the premium connection.The five making-up torques,that is under-torque,minimum torque,optimal torque,maximum torque,and over torque,were considered and the contact stress of premium connection and Von Mises stress were analyzed.The results show that sealing surface contact stress is greater than the tube body inter-nal pressure strength,under the action of less torques,and the connection can realize seal,but the auxiliary seal of the shoulder is lost.Under the action of over torque,the contact stress at the shoulder and the sealing surface is greater than the tube internal pressure strength,and the con-nection can realize sealing.Under the action of less or over torque,respectively bearing axial ten-sile,compression load and internal pressure,the sealing surface contact stress is greater than the tube body internal pressure strength,but the auxiliary seal of the shoulder have been lost.The contact stress of the sealing surface gradually decreases with the increase of the contact stress of the shoulder,when the torque is increased from the minimum torque.%考虑螺旋升角，采用弹塑性接触有限元法，应用 ABAQUS 有限元分析软件建立某特殊螺纹油管接头三维有限元模型；考虑欠扭矩、最小扭矩、最佳扭矩、最大扭矩、过扭矩5种不同上扣扭矩，分析了特殊螺纹油管接头的接触应力及 Von Mises 应力。结果表明：欠扭矩上扣后，密封面接触应力大于管体抗内压强度，能够实现密封，但台肩的辅助密封丧失；过扭矩上扣后，台肩和密封面处的接触应力均大于管体抗内压强度，能够实现密封；过、欠扭矩上扣后，分别承受轴向拉伸、压缩载荷与内压作用时，密封面接触应力都大于管体抗内压强度，但台肩的辅助密封都已经丧失；当扭矩从最小扭矩逐渐增大时，密封面接触应力随着台肩接触应力的增大而逐渐减小。