Citation: Ding, F.; Hong, T.; Xu, Y.;
Jia, X. Prediction of Fracture Behavior
of 6061 Aluminum Alloy Based on
GTN Model. Materials 2022, 15, 3212.
https://doi.org/10.3390/
ma15093212
Academic Editors:
Alberto Campagnolo and
Alberto Sapora
Received: 16 March 2022
Accepted: 21 April 2022
Published: 29 April 2022
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Article
Prediction of Fracture Behavior of 6061 Aluminum Alloy Based
on GTN Model
Fengjuan Ding
1,2
, Tengjiao Hong
1,3
, Youlin Xu
2
and Xiangdong Jia
2,
*
1
College of Mechanical Engineering, Anhui Science and Technology University, Bengbu 233100, China;
dingfengjuan@ahstu.edu.cn (F.D.); hongtengjiao@ahstu.edu.cn (T.H.)
2
College of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing 210037, China;
youlinxu@njfu.edu.cn
3
College of Mechanical Engineering, Yangtze University, Jingzhou 434023, China
* Correspondence: jiaxd.good@njfu.edu.cn; Tel.:+86-025-85427790
Abstract:
To determine the Gurson-Tvergaard-Needleman (GTN)damage model parameters of
6061 aluminum
alloy after secondary heat treatment, the uniaxial tensile test was carried out on
the aluminum alloy circular arc specimen, and the mechanical properties parameters and the load-
displacement curve of aluminum alloy tube were obtained. With the help of the finite element
reverse method, scanning electron microscope and a orthogonal test method, the GTN damage model
parameters (f
0
, f
N
, f
C
, and f
F
) were calibrated, and their values were 0.004535, 0.04, 0.1, and 0.2135,
respectively. Then the shear specimen and notch specimen were designed to verify the damage
model, the results show that the obtained GTN damage model parameters can effectively predict the
fracture failure of 6061 aluminum alloy after secondary heat treatment during the tensile process.
Keywords:
6061 aluminum alloy; GTN model; fracture; numerical simulation;
orthogonal experiments
1. Introduction
Faced with increasingly serious environmental pollution and energy consumption
problems, governments around the world have promulgated strict vehicle emission stan-
dards, such as China’s National VI emission standard, Europe’s Euro VI emission standard
and the US CAFE emission standard [
1
]. The main ways to achieve energy saving and
emission reduction in automobiles are to improve the level of lightweight, improve the
efficiency of power transmission, and optimize the aerodynamic parameters. Among them,
improving the level of light weight is the most convenient and effective implementation
plan. The “Made in China 2025” plan also requires that automobile manufacturers must in-
crease the application of lightweight materials in automobiles to achieve an average vehicle
weight reduction of 5~20% target. Aluminum alloys are widely used in the automotive field
due to their lightweight, high specific strength, corrosion resistance, good formability, and
recyclability. Problems such as local plastic instability, fracture, spring back, and wrinkling
occur, which affect the surface quality and dimensional accuracy of auto parts, resulting in
increased scrap rates. To improve the application rate of aluminum alloys in the field of
automotive lightweight, the mechanical properties of aluminum alloys, potential internal
micro-defects, formability, and the use environment and design requirements of auto parts
must be considered. Aluminum alloy materials are prone to fracture failure under the
action of forming and applied loads. To deeply study the fracture failure behavior of
aluminum alloy materials and establish a suitable failure model, it is necessary to study the
relationship between stress triaxiality and fracture strain. Therefore, scholars have paid
much attention to the influence of stress triaxiality on the ductile fracture of aluminum alloy
materials, to establish its fracture failure model, which can better predict the fracture failure
behavior of aluminum alloy, and further reduce the loss of aviation and automobile produc-
tion fields. At present, the Gurson-Tvergaard-Needleman (GTN) damage model is mainly
Materials 2022, 15, 3212. https://doi.org/10.3390/ma15093212 https://www.mdpi.com/journal/materials
