Subset-based local vs. finite element-based global digital image correlation: A comparison study

Theoretical and Applied Mechanics Letters

Bing Pan¹  Bo Wang¹ 

[1] Institute of Solid Mechanics, Beihang University, Beijing 100191, China;

关键词: Digital image correlation;    Displacement measurement;    Finite element;    Subset;    Subpixel;   

DOI  :  10.1016/j.taml.2016.08.003

来源: DOAJ

【 摘 要 】

Being the two primary approaches for full-field kinematics measurements, both subset-based local digital image correlation (DIC) and finite element-based global DIC have been extensively studied. Nowadays, most commercial DIC systems employ local DIC algorithm because of its advantages of straight forward principle and higher efficiency. However, several researchers argue that global DIC can provide better displacement results due to the displacement continuity constraint among adjacent elements. As such, thoroughly examining the performance of these two different DIC methods seems to be highly necessary. Here, the random errors associated with local DIC and two global DIC methods are theoretically analyzed at first. Subsequently, based on the same algorithmic details and parameters during analyses of numerical and real experiments, the performance of the different DIC approaches is fairly compared. Theoretical and experimental results reveal that local DIC outperforms its global counterpart in terms of both displacement results and computational efficiency when element (subset) size is no less than 11 pixels.

【 授权许可】

Unknown