基于ISO 13679的特殊螺纹接头上扣性能仿真分析

The simulation analysis on the make-up performance of premium connection based on ISO 13679

ISO 13679为目前通用的特殊螺纹接头评价标准,但其实物试验周期长、花销大。为探索有限元方法模拟试验的可行性,依据ISO 13679 IV级试验要求建立三维有限元模型,对标准中上扣试验进行仿真模拟,分析不同几何参数特殊螺纹接头在最大上扣扭矩作用下密封面及台肩处的应力分布状态及其密封性能。研究结果表明:密封面有效接触长度随密封过盈量的增加而减少;外螺纹锥度大、内螺纹锥度小时,密封面环向路径上接触压力最低,密封性能最差;所选特殊螺纹接头在9次上卸扣后,等效塑性应变随上卸扣次数增加而增大;三维有限元分析方法可有效模拟上扣试验过程,在一定程度上具有代替实物试验的可行性。

ISO 13679 is a general evaluation standard for premium connection but the full-scale test is costly.To explore the feasibility of finite element method,it builds the four types of three-dimensional finite element model based on the requirement of ISO 13679 CAL IV in ABAQUS,analyzes the effect of geometry parameters on stress distribution and sealing property.The results show that along sealing taper direction contact position moves to the left as the sealing interference increasing.The worst sealing performance occurs within minimum circumferential contact pressure when the taper of pin is bigger than the box.After nine times make-up break-out test,equivalent plastic strain increases within the times of make-up break-out.