Simulation And Parameter Optimization Of Flareless Tube Forming Connection Process

Aviation hydraulic conduits encounter high temperatures,low temperature,high pressures,and frequent pressure changes,often accompanied by external environment such as vibration and shock during aircraft flight,as a result,fatigue damage often occurs at the joint of the conduit,causing leakage or even damage,therefore,the reliability of aviation conduit joints is very important.This article addresses the characteristics of the flareless composite tube forming connection,the finite element simulation combined with the forming connection process test was used to optimize the process parameters of the flareless composite tube forming connection.The influencing factors of the flaring forming process of the flareless composite tube are determined by finite element numerical simulation.There are three main factors: the forming rubber sleeve size,the bulging pressure,and the gap between the pipe and the pipe sleeve.Analysis of finite element simulation results: DN8 flareless tube should be between23~23.8mm when the thickness of the rubber sleeve is 1.4mm,when the thickness is 1.5mm,the length should be between 21~21.8mm,The bulging pressure is 160~200Mpa;DN10flareless tube should be between 22~23.8mm when the thickness of the rubber sleeve is1.8mm,when the thickness is 1.9mm,the length should be between 20~22mm,The bulging pressure is 180~220Mpa.When the gap is 0.1mm,the bulging pressure should be increased by 20 Mpa to meet the requirements of the Aviation standard requirements.Flareless tube extrusion forming connection based on optimized process parameters,by analyzing the thickness distribution after forming and the simulation results,it can be found that the finite element simulation results are basically consistent with the thickness distribution of the produced pipe joints.The maximum error does not exceed 8%;And the formed duct passed the aviation duct durability test specified by Aviation standard requirements,the rationality of the modeling and the accuracy of the simulation results are verified.