title: Accurate three-dimensional shape and deformation measurement at microscale using digital image correlation.
abstract: Based on stereomicroscope and three-dimensional (3D) digital image correlation (DIC) method, a non-contact measurement technique is presented to measure the 3D shape and deformation data on miniature specimens and the corresponding microscopic measurement system is developed. A pair of cameras is mounted on a binocular stereo light microscope to acquire pairing micrographs from two different optical paths of a specimen surface spraying with speckle pattern. Considering complex optical paths and high magnification, an accurate equivalent relative calibration method, combining a priori warping functions, is proposed to correct image distortions and optimize the intrinsic and extrinsic parameters of stereomicroscope. Then, a fast one-dimensional synchronous stereo matching method, based on the DIC method and image rectification technique, is proposed to search for discontinuous corresponding points in the pairing micrographs. Finally, the 3D shape is reconstructed from the corresponding points, while the temporal micrographs acquired before and after deformation are employed to determine the full-field deformation. The effectiveness and accuracy of the presented microscale measurement technique are verified by a series of experiments.
authors.affiliation: School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Maodong
authors.initials: M
authors.lastname: Ren
authors.affiliation: School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Liang
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Leigang
authors.initials: L
authors.lastname: Li
authors.affiliation: School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wei
authors.affiliation: School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Lizhong
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Zhengzong
authors.initials: Z
authors.lastname: Tang
mesh_terms: D002138:Calibration; D004867:Equipment Design; D021621:Imaging, Three-Dimensional / Q000295:instrumentation* / Q000379:methods*; D055595:Mechanical Phenomena; D008853:Microscopy / Q000295:instrumentation* / Q000379:methods*