Innovative Techniques and Efficient Strategies For Numerical Modelling and Experimental Analysis of Symmetrical and Asymmetrical Incremental Sheet Forming Processes

Publications

A Polycrystal Model to Evaluate Mechanical Properties of Asymmetrically Rolled AL Sheets

Publication . Sousa, R. J. Alves de; Simões, F. J. P.; Grácio, J. J.; Yoon, J. W.

The asymmetric rolling process (ASR) differs from conventional rolling (CR) through the use of different roll circumferential velocities. Using proper parameters, asymmetric rolling imposes intense shear deformations across the sheet thickness, leading not only to the occurrence of shear texture, but also to grain refinement [1]. Some shear texture components are known to improve plastic strain ratio values, and consequently formability. In Simões et al. [4], a AA1050-O sheet was asymmetrically rolled and annealed. Shear texture was obtained, as opposed to typical gamma-fiber texture obtained on sheets rolled through the conventional process. Shear tests were used to evaluate strength and formability. A polycrystal plasticity model, as formulated by Gambin [2] and implemented by Alves de Sousa [3], was employed to evaluate texture evolution and to give a sounding theoretical basis for the improved mechanical properties on sheets after the process. For FCC materials, this approach avoids the uniqueness issue related to the choice of the set of active slip systems by applying a regularized Schmid Law. Consequently, it generates yield surfaces with smooth corners where the normal vector is always uniquely defined. In the following sections, implementation guidelines are given. The accuracy of simulation results and the advantages of the asymmetric rolling process, when compared to conventional rolling, are the main topics of discussion.

2010-06-12Journal article

Restricted access

Keywords

Incremental Forming,Finite Element Modelling,Experimental Validation,Plastic Deformation, Engineering and technology ,Engineering and technology/Materials engineering

Funding agency

Fundação para a Ciência e a Tecnologia, I.P.

Funding programme

Concurso para Projectos de I&D em todos os Domínios Científicos - 2008

Funding Award Number

PTDC/EME-TME/098845/2008