The Analysis on Flaring Process of Metal Tubes

• Main Authors: Jyh-Wha Chen, 陳志華
• Other Authors: Ching-Lun Li
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/50079312739467715716

碩士 === 淡江大學 === 機械工程學系 === 89 === A methodology for formulating an elasto-plastic finite element model, which based on an updated Lagrangian formulation(ULF), Prandtl-Reuss flow rule and von Mises yield condition, is developed to simulate the flaring process of metal tubes. An extended Algorithm is proposed to formulate the boundary conditions, such as nodal penetration and separation, alteration of sliding direction of friction, strain increment and rotational increment. A modified Coulomb’s friction law is introduced to describe the friction at contact interface. Under the condition of axial symmetry, the numerical simulation results include deformation diagrams in different forming stages, relationship between the punch load and punch displacement, relationship between the thickness reduce ratio and flaring ratio, relationship between the critical flaring ratio and half apex angle of punch, relationship between the critical punch fillet raduis and half apex angle of punch and the final shape of tubes after unloading. In addition, the influence of the fillet radius of punch is studied on flaring process of metal tubes. Extremely, the critical punch fillet radius which a start point of curling is studied. A set of flaring die is designed for experiments. It shows good agreement between the numerical simulation results and experimental outcomes and can be used to verify the rationality of the finite element programs developed in flaring process of metal tubes.