Simulation of the rolling of stator vanes Harm Wisselink
Contact info: Harm Wisselink Han Huetink Martien van Dijk Andre van Leeuwen h.h.wisselink@wb.utwente.nl j.huetink@wb.utwente.nl ID_eldim@eldim.nl ID_eldim@eldim.nl Introduction ELDIM manufactures among others stator vanes for the compressor of an aero engine (figure 1). These vanes are produced by a cold rolling process. The development of a rolling process for a new type of vane can take several cycles of trial and error, before all requirements are fulfilled. from strips of sheet metal
Analysis of guillotining and slitting, finite element simulations
Guillotining and slitting are two sheet metal cutting processes, which produce long straight cuts and can be seen as stationary processes. The analysis of these two processes is the subject of this thesis. This research project is part of a cluster of IOP projects on sheet metal cutting, originating from industrial requests for more fundamental knowledge, as sheet metal cutting is still mainly based on experience and trial and error. The objective is to develop models of guillotining and slitting to increase the insight and to contribute to the quality and productivity of these shearing processes.
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.