Buckling and forming processes of tubes with varying slenderness ratio (ratio of length to diameter) under external hydraulic pressure were analyzed with three-dimensional finite element method (FEM) for studying ...Buckling and forming processes of tubes with varying slenderness ratio (ratio of length to diameter) under external hydraulic pressure were analyzed with three-dimensional finite element method (FEM) for studying tube external pressure forming (EPF). Buckling pressures for different tube blanks without mandrel were predicted, and an EPF of a carbon steel tube onto a mandrel with six ribs was simulated. Both thickness distribution and buckling pressure from the simulations were found to be in agreement with those from experiments. Buckling pressures are shown to be a function of the slenderness ratio. The tubular part with six ribs produced by EPF has a uniform thickness distribution, whose maximum thinning rate is only 5.9%.展开更多
基金The authors would like to thank the Scientific Research Fund of Harbin Institute of Technology (Grant No. HIT.2002.33) the National Natural Science Foundation of China (Grant No. 59975021) for financial support of this research.
文摘Buckling and forming processes of tubes with varying slenderness ratio (ratio of length to diameter) under external hydraulic pressure were analyzed with three-dimensional finite element method (FEM) for studying tube external pressure forming (EPF). Buckling pressures for different tube blanks without mandrel were predicted, and an EPF of a carbon steel tube onto a mandrel with six ribs was simulated. Both thickness distribution and buckling pressure from the simulations were found to be in agreement with those from experiments. Buckling pressures are shown to be a function of the slenderness ratio. The tubular part with six ribs produced by EPF has a uniform thickness distribution, whose maximum thinning rate is only 5.9%.