摘要
为确定Chaboche混合硬化模型在大应变-变路径加载条件下的待定参数,提出了一种新的参数标定方法。首先,针对Al2024-T351铝合金设计了单轴等应变幅值拉压循环实验,得到了相应的应力-应变滞回曲线,通过推导混合硬化模型主控方程进行实验数据拟合,获得了随动硬化规律。随后,基于光滑圆棒料(SRB)单向拉伸试验的流动应力曲线和外推模型,将应力-应变关系外推至大应变范围。最后,利用保留前述随动硬化规律的Chaboche模型对大应变范围内的SRB流动应力曲线进行拟合,得到最终的Chaboche混合硬化模型参数。实验验证表明,所标定的Chaboche混合硬化模型能很好地预测大变形-变路径加载条件下材料的硬化行为。
A novel approach was introduced to calibrate the Chaboche combined hardening model under large-strain variable-path loading conditions. Firstly,uniaxial tension-compression cyclic tests with constant strain were designed for the Al2024-T351 aluminum alloy and the corresponding stress-strain cyclic hysteresis curves were plotted. By fitting the experimental data with the main equations of Chaboche model,the kinematic hardening law was obtained. Then,the flow stress curves obtained from smooth round bar( SRB) uniaxial tension were extrapolated to large-strain range by a proper extrapolation model. Finally,the SRB flow stress curves were fitted by using Chaboche combined hardening model preserving the the kinematic hardening law described above,and the finial parameters of Chaboche model were obtained. It is validated by the tests that the calibrated combined hardening model can give a better description of hardening behavior under large-strain variable-path loadings.
作者
马艳
王婷婷
庄新村
MA Yan;WANG Ting-ting;ZHUANG Xin-cun(Institute of Forming Technology and Equipment,Shanghai Jiao Tong University,Shanghai 200030,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2019年第5期276-282,共7页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(51575345)
国家科技重大专项(2018ZX04024001-004)
关键词
Chaboche混合硬化模型
拉压循环滞回曲线
大应变
变路径加载
Chaboche combined hardening model
tension-compression cyclic hysteresis curve
large-strain
variable-path loading
