航空扩口导管连接仿真及结构参数研究

Simulation and Parameter Study on Connection Structure of Aviation Flared Pipe

航空扩口导管是飞机压力传递和物质输运的主要载体,在长期使用中存在连接渗漏问题。针对航标规定的两种尺寸系列连接结构,分别采用二维旋转轴对称模型对航空扩口导管及连接件进行仿真分析,得到结构的等效应力、等效塑性应变以及密封面的接触应力分布规律。选取密封面摩擦系数,接头锥形小端的倒圆角半径以及导管扩口角度作为变化参数,研究了结构参数对密封面的接触应力与密封性能的影响规律。结果表明:第2尺寸系列结构的密封性能优于第1尺寸系列;密封面摩擦系数越小,接触应力越大,有利于提高密封性能;增大接头锥形小端的倒角半径,使得倒角处接触应力提高;导管的扩口角度越小,密封面平均接触应力越高,进而提高导管连接的密封性能。研究结果可为航空导管密封性能优化提供参考。

Aviation flared pipe is the main carrier of aircraft pressure transmission and material transport,which has leakage problem in long-term use.According to the two size series connection structures specified in the aviation industry standard,the equivalent stress,equivalent plastic strain and contact stress distribution of the sealing surface are obtained by using two-dimensional rotational symmetry simulation model.The friction coefficient of sealing surface,the fillet radius of small end of tapered part of joint and flare angle of the pipe are selected as the variable parameters to study the influence of the structural parameters on the contact stress and sealing performance of the sealing surface.The results show that the sealing performance of the second size series is better than that of the first size series;the smaller the friction coefficient of the sealing surface is,the greater the contact stress is,which is beneficial to improve the sealing performance;increasing the fillet radius of the small tapered end of the joint increases the contact stress of the small tapered end;the smaller the flaring angle of the pipe,the higher the average contact stress of the sealing surface,and then improve the sealing performance of the pipe connection.The results can provide a reference for the optimization of the sealing performance of aviation pipe.