摘要
数字图像相关法作为一种直接有效的非接触、全场光学测量方法,已广泛地应用于各个领域材料和结构的二维/三维位移和应变测量。结合先进的散斑制备技术,在显微镜下进行原位加载实验,可实现微尺度数字图像相关位移和应变测量。微尺度下试样加载过程中将不可避免地出现离面位移,由于光学显微镜景深限制,微小的离面位移将导致散斑图像失焦模糊,从而为变形测量带来相应的误差。为减小这种失焦模糊带来的误差,采用盲去卷积方法对散斑图像去模糊,并针对噪声问题采用高斯滤波的方法对散斑图像进行去噪,定量分析了图像复原对数字图像相关测量精度的影响,并对indium tin oxide(ITO)薄膜进行了拉伸实验。实验结果表明,图像复原后测量的弹性模量误差减小了13.91%,应变测量结果的精度与稳定性更高。
As a direct and effective non-contact full-field optical measurement method,the digital image correlation method has been widely used in 2D/3D displacement and strain measurements of materials and structures in various fields.Combined with advanced speckle preparation technology,in situ loading experiments are conducted under a microscope,which can realize the displacement and strain measurements of micro-scale digital image correlation.Out-of-plane displacement inevitably occurs in the loading process of specimens at the micro scale.Because of the limitations of the depth of field of optical microscopes,small out-of-plane displacement leads to defocus blurring of speckle images,which generates a corresponding error in deformation measurements.To reduce the error caused by out-of-focus blur,the blind deconvolution method is used to blur the speckle image,and the Gaussian filtering method is used to denoise the speckle image to address noise problems.The effects of image restoration on the digital image correlation measurement accuracy are analyzed quantitatively,and a stretching experiment of an indium tin oxide(ITO)film is conducted.Experimental results show that the error in elastic modulus measurement after image restoration is reduced by 13.91%,and the accuracy and stability of the strain measurement results are higher.
作者
韩伟
吴丹
Han Wei;Wu Dan(School of Mechanical Engineering and Mechanics,Ningbo University,Ningbo 315211,Zhejiang,China)
出处
《激光与光电子学进展》
CSCD
北大核心
2023年第14期36-46,共11页
Laser & Optoelectronics Progress
关键词
图像处理
数字图像相关
图像复原
噪声去除
微尺度
变形测量
image processing
digital image correlation
image restoration
noise removal
micro-scale
deformation measurement
