Tool deformation during the shape rolling of stator vanes
Tool deformation is an important issue in the shape rolling of stator vanes as it directly 
influences the thickness of the rolled vane. This means that for the design of an accurate production process 
the deformation of the tools has to be accounted for. The shape rolling of symmetrical straight vanes has been 
investigated. This rolling process is considered stationary, because these vanes have a constant cross-section 
over the length. Therefore an ALE formulation is suitable to calculate the steady state. The deformation of 
the sheet as well as the deformation of the tools have been calculated with the developed finite element model. 
Some results of these simulations are presented in this paper
3D FEM Simulations of a shape rolling process
A finite element model has been developed for the simulation of the shape rolling of stator 
vanes. These simulations should support the design of rolling tools for new vane types. For the time being 
only straight vanes (vanes with a constant cross-section over the length) are studied. In that case the rolling 
process can be considered stationary and an ALE formulation is suitable to calculate the steady state. Results 
of simulations and experiments for a symmetrical straight vane are presented
Application of damage models in metal forming
The development of damage models in the analysis of metal forming processes, to characterize the formability limits, is an important area of ongoing research. In this paper, two energy-based damage models for the simulation of crack initiation in metal forming processes are presented. The first one is an isotropic damage model with two damage variables. The second one is an anisotropic model with a damage characteristic tensor. The damage models are developed within the general framework of continuum thermodynamics for irreversible processes by identifying a proper set of internal variables together with their associated generalized forces. An approach is proposed to account for microcrack opening and closing. A viscoplastic regularization algorithm is used to take into account the strain rate effect and to improve numerical stability. Both models have been incorporated into the finite element code, LAGAMINE. The models were applied to simulations of upsetting of collar cylinders and nonisothermal hemispherical punch stretching. The results of the analyses were validated by comparing the finite element simulations with experimentally obtained data.