Improved Digital Image Correlation Method for Eliminating Pixel Shape-Induced Errors in Shear-Strain Calculations

• DOI: 10.1520/jte20120085
• Publication Date: 2013-02-05T23:08:31Z
• Authors: Bei Peng; Chengcheng Huang; Wu Zhou; Huijun Yu; Zhi Zeng
• Keywords: Digital image correlation; Strain (injury)

Abstract Digital image correlation is widely used in non-contact displacement/strain measurements for numerous engineering applications. Under rigid body rotation or shear deformation, however, the calculated surface strain of specimens unreliable when camera pixels are characterized by non-square geometry, that is, width-to-height ratio not 1. This study analyzes computational errors introduced cameras, and proposes a modified least-squares method eliminates such field calculated. Experimental results confirm algorithm validly effectively computes strain.