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Title: Approaches To Modelling Of Elastic Modulus Degradation In Sheet Metal Forming

Abstract

Strain recovery after removal of forming loads, commonly defined as springback, is of great concern in sheet metal forming, in particular with regard to proper prediction of the final shape of the part. To control the problem a lot of work has been done, either by minimizing the springback on the material side or by increasing the estimation precision in corresponding process simulations. Unfortunately, by currently available software springback still cannot be adequately predicted, because most analyses of springback are using linear, isotropic and constant Young's modulus and Poisson's ratio. But, as it was measured and reported, none of it is true. The aim of this work is to propose an upgraded mechanical model which takes evolution of damage and related orthotropic stiffness degradation into account. Damage is considered by inclusion of ellipsoidal cavities, and their influence on the stiffness degradation is taken in accordance with the Mori-Tanaka theory, adopting the GTN model for plastic flow. With regard to the case in which damage in material is neglected it is shown in the article how the springback of a formed part differs, when we take orthotropic damage evolution into consideration.

Authors:
 [1]; ;  [2]
  1. Kovinoplastika Loz, Stari trg pri Lozu (Slovenia)
  2. Laboratory for Numerical Modelling and Simulation, Faculty of Mechanical Engineering, University of Ljubljana, Ljubljana (Slovenia)
Publication Date:
OSTI Identifier:
21057018
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 907; Journal Issue: 1; Conference: 10. ESAFORM conference on material forming, Zaragoza (Spain), 18-20 Apr 2007; Other Information: DOI: 10.1063/1.2729518; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALLOYS; COMPUTER CODES; COMPUTERIZED SIMULATION; CONTROL; FLEXIBILITY; METALS; NUMERICAL ANALYSIS; PLASTICITY; POISSON RATIO; SHEETS; STRAINS; YOUNG MODULUS

Citation Formats

Vrh, Marko, Halilovic, Miroslav, and Stok, Boris. Approaches To Modelling Of Elastic Modulus Degradation In Sheet Metal Forming. United States: N. p., 2007. Web. doi:10.1063/1.2729518.
Vrh, Marko, Halilovic, Miroslav, & Stok, Boris. Approaches To Modelling Of Elastic Modulus Degradation In Sheet Metal Forming. United States. doi:10.1063/1.2729518.
Vrh, Marko, Halilovic, Miroslav, and Stok, Boris. Sat . "Approaches To Modelling Of Elastic Modulus Degradation In Sheet Metal Forming". United States. doi:10.1063/1.2729518.
@article{osti_21057018,
title = {Approaches To Modelling Of Elastic Modulus Degradation In Sheet Metal Forming},
author = {Vrh, Marko and Halilovic, Miroslav and Stok, Boris},
abstractNote = {Strain recovery after removal of forming loads, commonly defined as springback, is of great concern in sheet metal forming, in particular with regard to proper prediction of the final shape of the part. To control the problem a lot of work has been done, either by minimizing the springback on the material side or by increasing the estimation precision in corresponding process simulations. Unfortunately, by currently available software springback still cannot be adequately predicted, because most analyses of springback are using linear, isotropic and constant Young's modulus and Poisson's ratio. But, as it was measured and reported, none of it is true. The aim of this work is to propose an upgraded mechanical model which takes evolution of damage and related orthotropic stiffness degradation into account. Damage is considered by inclusion of ellipsoidal cavities, and their influence on the stiffness degradation is taken in accordance with the Mori-Tanaka theory, adopting the GTN model for plastic flow. With regard to the case in which damage in material is neglected it is shown in the article how the springback of a formed part differs, when we take orthotropic damage evolution into consideration.},
doi = {10.1063/1.2729518},
journal = {AIP Conference Proceedings},
number = 1,
volume = 907,
place = {United States},
year = {Sat Apr 07 00:00:00 EDT 2007},
month = {Sat Apr 07 00:00:00 EDT 2007}
}
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