Mechanics Analysis Of Bimetal Tube Plastic Forming And The Equipment Research

Bimetal tube is a new type tube which is made of two different metal material.It is complex utlized the advantages of the inner and outer tubes material,so it has a widely foreground application.In this dissertation, the plastic expansion composite framing theroy and technology for bimetal tube had been researched and the equipment of bimetal tube plastic forming had been investigated.Based on the theroy of expansion of clad pipe, considering the effects of the material mechnical properties on the plastic forming thechnology for bimetal tube,the study discovered that the core factors in plastic forming are Yong's modulus and flow stress of joined pairs because of their crucial effects on elastics recovery of joinedpairs,so this paper has presented the theoretical gist ,which satisfies theinner and outer tubes to be plasitc forming composited .It is discovered through the analysis of Residual contact pressure Graphic Method that not the yield stress but the innner tube flow stress under the load of the tube expanding pressure applied. The concept of the calcuation of residual contact pressure are put forward which based on the equivalent yield stress.Based on the ealsitc-plastic theroy,the theorical calucation formulas relating the expanding pressure to the residual contact pressure have been derived according to the distortion property of outer tube ,and its calculation results are consistent with the FEA results. The thickness of the outer tube is too thick which is disadvantage of the bimetal tube palstic forming,rduce the originality gap of the inner and outer tube and increase the thickness of the inner tube can improve the residual pressure.Based on the principal of the residual contact pressure variety with the heat loading, the mechanism of bimetal tube looseness has...