光学学报, 2020, 40 (3): 0312001, 网络出版: 2020-02-10
基于最小一乘拟合的非均匀应变的数字图像相关测量 下载: 997次
Inhomogeneous Strain Measurement Based on Least Absolute Deviation Fitting for Digital Image Correlation
测量 数字图像相关方法 非均匀应变 最小一乘拟合 最小二乘拟合 measurement digital image correlation method inhomogeneous strain least absolute deviation fitting least square fitting
摘要
数字图像相关 (DIC) 方法是一种重要的位移和应变非接触式测量方法。为了对物体的非均匀应变进行准确测量,在DIC方法中引入位移最小一乘拟合,鉴于最小一乘拟合解析方法求解困难,采用基于模拟退火的混合粒子群算法进行求解。开展了虚拟剪切带形成的数值实验和相似材料断层滑移实验,并对非均匀变形条件下最小一乘拟合和最小二乘拟合的应变测量结果进行对比。研究发现:对于非均匀应变测量,最小一乘拟合的结果要优于最小二乘拟合;而对于均匀应变测量,两种方法具有相同的精度。
Abstract
The digital image correlation (DIC) method is an important non-contact displacement and strain measurement method. To accurately measure inhomogeneous strain, least absolute deviation fitting of displacements is introduced into the DIC method. As least absolute deviation fitting cannot be solved by analytical methods, a hybrid particle swarm optimization algorithm based on simulated annealing is used. By conducting numerical experiments on the formation of fictitious shear band and the similar material fault slip experiment, the strain measurement results of least square fitting and least absolute deviation fitting for inhomogeneous strain measurements are compared. Results show that the inhomogeneous strain measurement accuracy for least absolute deviation fitting is better than that for least square fitting, while these two methods exhibit the same accuracy for the homogeneous strain measurement.
王学滨, 董伟, 杨梅, 张博闻, 余斌. 基于最小一乘拟合的非均匀应变的数字图像相关测量[J]. 光学学报, 2020, 40(3): 0312001. Xuebin Wang, Wei Dong, Mei Yang, Bowen Zhang, Bin Yu. Inhomogeneous Strain Measurement Based on Least Absolute Deviation Fitting for Digital Image Correlation[J]. Acta Optica Sinica, 2020, 40(3): 0312001.