Analysis of superplastic sheet-metal forming in a circular closed-die considering non-uniform thinning

Progress on superplasticity and superplastic forming in Taiwan during 1987–1997

“…Hwang's and Huang's groups in National Sun Yat-Sen University also made great efforts on SPF/DB of aluminum alloys. A series of self-written computer programs for pressure pro®les and thickness distributions, based on ®nite difference methods, have been completed in simulation and comparison with experimental observations [2,5,11,14,19,24]. The program incorporated the strain hardening exponent (n-value) additionally into the constitutive equation for the simulation, i.e., the equation ' K H 4 n 4 m was used.…”

“…The program incorporated the strain hardening exponent (n-value) additionally into the constitutive equation for the simulation, i.e., the equation ' K H 4 n 4 m was used. The model also incorporates the non-uniform thinning effect during free bulging [19]. In addition, the effects of different friction coef®cients at different locations of the formed part can be considered, using different friction coef®cients, such as " 0 (complete sliding), " 0.01±0.1 (different degrees of partial sliding), or " I (complete sticking) for each selected position [5,11,19,24].…”

“…The model also incorporates the non-uniform thinning effect during free bulging [19]. In addition, the effects of different friction coef®cients at different locations of the formed part can be considered, using different friction coef®cients, such as " 0 (complete sliding), " 0.01±0.1 (different degrees of partial sliding), or " I (complete sticking) for each selected position [5,11,19,24]. It was found that the lubrication effect after the onset of SPF becomes different at different positions of the formed part.…”

Stress–strain relation during superplastic uniaxial tension at constant tension velocity

“…Process modelling has been widely used in the SPF industry to provide effective guidance for optimizing processes due to the complexity of the forming processes [39][40][41]. Thus, the precise characterization of constitutive behavior is crucial for the simulation and process optimization of SPF [40,42,43].…”

High-Temperature Forming of a Vehicle Closure Component in Fine-Grained Aluminum Alloy AA5083: Finite Element Simulations and Experiments

“…A large fraction of the existing literature on simulation of hot gas-pressure forming has employed simple forming geometries, such as uniaxial tension, axially-symmetric bulge forming (balanced biaxial tension) or uncomplicated shapes that produce a plane-strain condition [11][12][13][14]. In plane strain deformation, the main interest is often prediction of localized sheet thinning in the vicinity of a die entry radius.…”