Doctoral Dissertations


Yunlu Zhang

Keywords and Phrases

Digital image correlation; Experimental mechanics; Image registration; Material testing


"Digital image correlation (DIC) is a non-contact full-field optical measurement method. With the advantages of high accuracy, low cost, and simple implementation, it has been widely applied in the area of experimental mechanics. In this study, DIC algorithm has been improved in the aspects of the pixel-level searching method and reference frame update strategy. The feature matching based method is proposed to provide an initial guess for all points of interest with semi-subpixel level accuracy in cases with small or large translation, deformation, or rotation. The bisection searching strategy is presented to automatically adjust the frame step for varying practical circumstances.

The improved DIC algorithm is implemented and applied to the miniature tensile test. A convenient experimental method to determine the true stress-strain curve is proposed. The instantaneous cross-section area is estimated by only one camera in aid of DIC method. The derived true stress-strain curves and mechanical parameters of metal material Al6061 and CP-Ti from miniature specimens match well with the results of standard specimens, and no dimension dependence has been observed in the results"--Abstract, page iv.


Liou, Frank W.

Committee Member(s)

Chandrashekhara, K.
Pan, Heng
Chen, Lianyi
Newkirk, Joseph William


Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering


Missouri University of Science and Technology

Publication Date

Fall 2019

Journal article titles appearing in thesis/dissertation

  • Improved initial guess with semi-subpixel level accuracy in digital image correlation by feature based method
  • Bisection searching based reference frame update strategy for digital image correlation
  • Determination of constitutive relation from miniature tensile test with digital image correlation


xi, 93 pages

Note about bibliography

Includes bibliographic references.


© 2019 Yunlu Zhang, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 11660

Electronic OCLC #