Experimental and numerical investigation on plasticity and fracture behaviors of aluminum alloy 6061-T6 extrusions
Experimental and numerical investigation on plasticity and fracture behaviors of aluminum alloy 6061-T6 extrusions
复制标题
铝合金 6061-T6 挤压材塑性和断裂行为的实验和数值研究
DOI：
10.1007/s43452-021-00225-3
复制
发表时间：
2021-05
影响因子：
4.4
通讯作者：
欧阳元文
中科院分区：
文献类型：
--
作者：
朱沛华;张其林;徐洪俊;欧阳元文
铝合金6061-T6（AA 6061-T6）型材已广泛应用于大跨度网壳。然而，利用细观力学手段对铝合金大变形和断裂行为的研究还不够。本文重点研究 AA 6061-T6 挤压材在各种应力状态下的塑性和断裂行为。对光滑和有缺口的圆棒、槽板和剪切板进行了实验。据观察，屈服应力随着缺口或凹槽半径的减小而减小。平面应变或纯剪切下的屈服应力低于轴对称拉伸下的屈服应力。此外，从拉伸试样测试获得的真实应力-真实应变数据高估了大变形时的硬化行为。为了充分描述这些实验观察结果，提出了一种考虑压力依赖性、洛德角效应和颈缩校正后硬化的新塑性模型。对于延性断裂，采用损伤诱导软化的修正莫尔-库仑断裂模型来预测不同应力状态下裂纹的萌生和扩展。塑性和断裂的材料模型通过材料子程序VUMAT数值实现到有限元代码ABAQUS/explicit中。研究发现，材料模型可以很好地预测所有样本的总体标称应力-应变曲线和断裂模式。对于实际工程设计，给出了AA 6061-T6型材的剪切强度和高三轴拉伸强度的推荐折算值。
Aluminum alloy 6061-T6 (AA 6061-T6) extrusions have been widely applied in large-span reticulated shells. However, researches on behaviors of the aluminum alloy under large deformation and fracture by means of meso-mechanics are still insufficient. This paper focuses on the plastic and fracture behaviors of AA 6061-T6 extrusions over a wide range of stress states. Experiments on smooth and notched round bars, grooved plates and shear plates are conducted. It is observed that the yield stress decreases as the notch or groove radius decreases. The yield stress under plane strain or pure shear is lower than that under axisymmetric tension. In addition, true stress-true strain data obtained from tensile coupon tests overestimate the hardening behavior at large deformation. To fully describe these experimental observations, a new plastic model considering the pressure dependence, Lode angle effect, and hardening with post-necking correction is proposed. Regarding the ductile fracture, modified Mohr-Coulomb fracture model with damage-induced softening is adopted to predict crack initiation and propagation under different stress states. The material models of plasticity and fracture are numerically implemented into FE code ABAQUS/explicit by the material subroutine VUMAT. It is found that both the overall nominal stress-strain curves and fracture patterns for all specimens are well predicted by the material models. For practical engineering design, recommended reduced values of shear strength and high-triaxiality tensile strength of AA 6061-T6 extrusions are given.
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DOI：
--
发表时间：
2013
期刊：
Journal of Building Structures
影响因子：
--
作者：
Chen Yiyi
通讯作者：
Chen Yiyi
DOI：
10.2172/6628920
发表时间：
1980-10
期刊：
--
影响因子：
--
作者：
M. Wilkins;R. Streit;J. Reaugh
通讯作者：
M. Wilkins;R. Streit;J. Reaugh
影响因子：
9.8
作者：
T. Stoughton;J. Yoon
通讯作者：
T. Stoughton;J. Yoon
影响因子：
2.6
作者：
R. Glüge;S. Bucci
通讯作者：
R. Glüge;S. Bucci
影响因子：
6.4
作者：
Shi, Mingzhe;Xiang, Ping;Wu, Minger
通讯作者：
Wu, Minger