Residual stress measurement via digital image correlation and sharp indentation testing
Residual stress measurement via digital image correlation and sharp indentation testing
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DOI：
10.1117/1.oe.55.12.124102
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发表时间：
2016-12
影响因子：
1.3
通讯作者：
Jinlong Chen;Jihua Liu;Cuiru Sun
中科院分区：
文献类型：
--
作者：
Jinlong Chen;Jihua Liu;Cuiru Sun
抽象的。提出了一种将数字图像相关法(DIC)与尖锐压痕测试相结合的表面残余应力的光学半结构检测方法。基于扩展腔模型，当半无限体受到均匀的等双轴残余应力或外加应力时，压痕周围的表面位移满足径向轮廓。因此，可以确定半无限体表面上的径向位移与残余应力或外加应力之间的关系。利用压痕实验对铝在不同应力状态下的应力关系进行了验证。这些状态是使用具有两个独立的正交加载轴的应力产生设置来产生的。用DIC测量位移。由于实验数据基本呈线性关系，在理论分析的基础上，采用非线性曲线拟合法和线性曲线拟合法分别得到了残余应力的大小。计算结果与外加应力值吻合较好。
Abstract. An optical and semidestructive method to determine surface residual stress, which combines digital image correlation (DIC) with sharp indentation testing, is proposed. Based on the expanding cavity model, when a semi-infinite body is subjected to uniform equi-biaxial residual or applied stresses, the surface displacement around the indentation satisfies radial profiles. Therefore, the relation between the radial displacement and the residual or applied stresses on the surface of a semi-infinite body can be determined. The described relation was tested using indentation experiments for different applied stress states in aluminum. These states were generated using a stress-generating setup with two independent orthogonal loading axes. DIC was used to measure the displacement. The magnitude of the residual stress was obtained using nonlinear curve fitting based on theoretical analysis, as well as linear curve fitting since the experimental data almost had a linear relationship. The calculations are in good agreement with the values of applied stresses.