Forming Limit Prediction of Anisotropic Aluminum Magnesium Alloy Sheet AA5052-H32 Using Micromechanical Damage Model
- PDF / 2,598,707 Bytes
- 15 Pages / 593.972 x 792 pts Page_size
- 24 Downloads / 232 Views
JMEPEG https://doi.org/10.1007/s11665-020-04987-4
Forming Limit Prediction of Anisotropic Aluminum Magnesium Alloy Sheet AA5052-H32 Using Micromechanical Damage Model Hao H. Nguyen and Hoa C. Vu (Submitted February 19, 2020; in revised form June 22, 2020) This paper focuses on the implementation and applicable evaluation of a modified Gurson–Tvergaard– Needleman (GTN) damage model for predicting forming limit diagram of anisotropic aluminum alloy sheet, in which its elasto-plastic behavior is assumed to obey a non-quadratic anisotropic yield criterion. The original porous ductile material model is heuristically enhanced to suit anisotropy of sheet metal, and then, it is implemented via a user material subroutine using finite element codes of ABAQUS/Explicit software package. The material damage model is calibrated and applied to predict forming limit diagram of commercial aluminum alloy sheet AA5052-H32 via the Nakajima drawing tests under plane stress condition. To obtain various strain paths, the Nakajima tests are conducted for seven specimens, which are designed in accordance with standard ISO 12004-2-2008. The influence of material anisotropy on the predicted forming limit is also considered and discussed. The numerical simulation results obtained from the proposed damage model showed a good agreement with those of the experimental data. Keywords
AA5052-H32 sheet, dung damage model, forming limit diagram, Nakajima test
1. Introduction Modeling material damage has been conducted since several previous decades. Until now, the ductile fracture phenomenon of metallic materials and their alloys has proved due to microvoid nucleation, growth, and coalescence (Ref 1). The sheet metals have been widely applied to the automotive industry and civil engineering thanks to their high strength and lightweight. The manufacturing processes of machined components and civil products usually involve waste products due to fractured initiation. In order to save time and to avoid waste, the computational simulations using finite element codes are commonly applied for investigating ductile fracture, forming limit diagram, elasto-plastic behavior, and more of metallic material. The phenomenological approach, based on micromechanical damage mechanics theory, is usually used for predicting ductile crack initiation and propagation. The anisotropy of matrix material is assumed to obey a quadratic yield criterion (Ref 2), or a non-quadratic yield criterion (Ref 3-5) depends on the crystal lattice structure of each material. However, such as yield criteria did not account for damage evolution during the deformed material process that is just anisotropic plasticity only. To employ these criteria for predicting ductile damage, the continuum damage mechanics theory integrated with the uncoupled damage criteria is preferred. Some recently uncouHao H. Nguyen and Hoa C. Vu, Department of Engineering Mechanics, Ho Chi Minh City University of Technology, Viet Nam National University-Ho Chi Minh City, Ho Chi Minh City, Viet Nam. Contact e-mail: vucon
Data Loading...
