两种油管气密封螺纹接头性能仿真

采用三维有限元仿真方法对VAM TOP、NK3SB两种气密封螺纹接头在上扣、拉伸载荷及弯曲载荷3种工况下的联接及密封性能进行研究,并对两种扣型的性能进行对比分析。结果表明:两种扣型台肩与密封面过渡区域有较为严重的应力集中,是气密扣结构最薄弱环节;上扣工况密封面接触应力沿周向表现出一定的螺旋特性, NK3SB扣型主密封受螺纹影响较小,VAM TOP副密封受螺纹影响较小;拉伸工况NK3SB螺纹应力分布更为均匀,弯曲工况VAM TOP螺纹应力波动较小;拉伸及弯曲工况下,NK3SB扣型球面/锥面主密封性能更为优异,VAM TOP反向台肩副密封性能更优异。
The connection and sealing performances of VAM TOP and NK3SB tubing airtight screw joints under loads of buckle, tension and bending were studied by the method of three-dimensional finite element simulation,and the performances of the two types of buckles were compared.The results show that there is a serious stress concentration in the transition zone between the shoulder and sealing surface,and it is the weakest link in the airtight buckle structure.The stress distribution of sealing face shows a certain spiral characteristic along the circle under the connection condition. Comparing the two types of buckles, the influence of the primary sealing of NK3SB caused by threads is smaller, and the influence of the auxiliary sealing of VAM TOP caused by threads is smaller. The thread stress distribution of NK3SB is more uniform under the tensile load, and the stress fluctuation of VAM TOP is smaller in the bending load.The NK3SB spherical/conical sealing performance and VAM TOP reverse shoulder sealing performance are more excellent under tensile and bending loads