Study On Numerical Simulation And Technology For Internal High-pressure Forming Process Of Mute Tube

Internal high-pressure forming technology has obtained the swift and violentdevelopment along with the development of the auto industry. As a new type of cleanand flexible process, Internal high-pressure has got the recognition of manufacturing.As internal high pressure forming technology developing rapidly in the automobileindustry, the welded tube billet in high pressure bulging technology has been widelyused which is also a difficult point at the same time. Therefore, it is of vitalimportance to research the welded tube billet in high pressure bulging technology.The paper researches the bulging process of the mute tube which based ontaking the mute tube as the research object through the method of combiningtheoretical analysis, numerical simulation and experiment. With the help of the finiteelement analysis software-DYNAFORM, the paper analyzes the variation of thestrain near the weld in the forming process and compares the impact of the threedifferent loading paths on the quality of the sound tube forming. This paper alsoresearches the experiment and analysis of the forming process of tube and finallydetermines the loading path of the concave curve is the optimal one.In order to do the further studies on the changes of the strain near the weld inthe bulging process of the mute tube, this paper uses the marc software to analyze thebulging process of the mute tube with simulating the finite element. The results ofusing the marc software to analyze finite element is better than the one withdynaform. This paper analyses the changes of equivalent strain near the weld duringthe process of internal high-pressure forming, including the preliminary formingstage, the laminated stage and the bulging end stage. By comparing with theexperimental results of internal high pressure forming process of the mute tube, theequivalent stress on the weld and heat affected zone near the weld in the process is the bigger one. And this position is also the most prone to fracture.