Experimental investigation of dynamic out of plane displacement error in 3D digital image correlation

With the development and implementation of digital image correlation (DIC) in static and dynamic experimentation, a deeper understanding of the variation of measurement error due to the experimental setup is sought. In this investigation, dynamic rigid body motion is measured using two high speed digital CMOS cameras paired with 3D digital image correlation (3D-DIC), a single point laser vibrometer, and a single axis accelerometer. To determine measurement error, a comparison is made between the measured displacement, velocity, and acceleration in the frequency domain. Prior to dynamic testing, characterization experiments with no motion were performed to determine potential sources of noise in a static environment. It was shown that the camera cooling fans and source of lighting can contribute to measurement noise. Dynamic experiments were designed to investigate the potential effect camera angle, sampling rate, and shutter speed have on measurement error. In addition to the 3D-DIC setup, speckle patterns with varying size, distribution, and randomness were investigated. Results show that the 3D-DIC setup and speckle pattern characteristics can affect the measurement error and measurement quality.