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Contribution à la caractérisation et à la modélisation de l'influence de la vitesse et de la température sur le comportement en découpage de tôles minces

Abstract : Blanking of thin sheets in copper alloys is a widely used forming process for manufacturing electronic components. Two main features enable to characterize this process: on one hand, the cut edge profile represents the quality of the product and on the other hand, the blanking force leads to the definition of the tools (materials of the punch and the die, speed and power of the mechanical presses, etc.). Numerical modelling allows us to quickly obtain answers concerning these two aspects without experiments. Within the research team “Modelling of Materials Forming” of the Applied Mechanics Laboratory R. Chaléat, a finite element software untitled Blankform© and dedicated to the two-dimensional simulation of blanking has been developed for a few years.
In order to obtain a better numerical prediction of the blanking force, we first perform the experimental characterization of the thermo-elasto-viscoplastic behaviour of the CuNiP copper alloy by tensile tests at imposed temperatures and strain rates. A specific constitutive law, which takes account of the material sensitivity to strain rate and temperature, is proposed based on experimental results. After the implementation of this law into the finite element software, the blanking simulation of thin sheets in CuNiP alloy shows that the maximum blanking force is correctly predicted.
During the blanking process, several materials like Cua1 copper present a phenomenon of dynamic recrystallization. Tensile tests on this copper allow us to characterize the mechanical behaviour of the material. Then a thermo-elasto-viscoplastic model with dynamic recrystallization is proposed within the framework of the thermodynamics of the irreversible processes. The application of this model to blanking process shows that it qualitatively predicts the phenomena observed in experiments for the Cua1 copper.
The two-dimensional modelling of blanking is often used for stamp parts of simple shapes. However, for complex shapes, it is necessary to solve the problem by a three-dimensional analysis. Using an industrial study case, a three-dimensional modelling of blanking is carried out in order to study the influence of the technological parameters on the distributions of the stresses and the strains. The numerical results corroborate the experimental observations on terms of cut edge profile.
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Contributor : Abdelhamid Touache <>
Submitted on : Wednesday, February 21, 2007 - 12:14:20 PM
Last modification on : Thursday, November 12, 2020 - 9:42:05 AM
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  • HAL Id : tel-00132399, version 1

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Abdelhamid Touache. Contribution à la caractérisation et à la modélisation de l'influence de la vitesse et de la température sur le comportement en découpage de tôles minces. Mécanique [physics.med-ph]. Université de Franche-Comté, 2006. Français. ⟨tel-00132399⟩

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