Critical imaging parameters in time resolved digital image correlation (TRDIC): effect of optical blur during drop test on composite structures

High speed imaging is applied for drop test on composite samples. The effect of optical blur on image correlation accuracy is described. Blur magnitude is tuned by decreasing the exposure time (at constant sensor sensitivity) for the same drop test series on flyspecked composite plates, while focus, aperture and 1:1 magnification are kept constant. Frame rate (80-20kfps) and lighting are changed while keeping the same image contrast. Results show correlation quality is already altered with subpixel blur. This study enables to define blur criterion in high-speed imaging and completes study about sampling rate effect in time resolved image correlation by high-speed imaging.

Automated summary

High speed imaging was used for drop testing composite samples, with the study focusing on the impact of optical blur on image correlation accuracy. By adjusting blur magnitude through decreasing exposure time, the study found that even subpixel blur can alter correlation quality in high-speed imaging. The research also helps define a blur criterion for high-speed imaging and completes the study on the sampling rate effect in time resolved image correlation.