Application of digital image correlation technique for measuring dynamic parameters during impact loading

Traditionally, many contact sensors have been employed to collect the data during an impact test. Often to select the appropriate data acquisition equipments and sensors, prior knowledge of the magnitude of the peak crushing force and the duration of the crash event is important. However, this is not an easy task. Any improper selection would lead to loss of sensors and equipments. So a contact-less method is an interesting alternative to collect the data during such dynamic events. In this paper, the digital image correlation technique (DIC) is used to measure the impact velocity and the corresponding impact force. To validate the method an axial impact test has been carried out with different specimens such as polyurethane foam, empty metal cans and composite tubes. The effect of different parameters such as the frame rate and subset size on the impact parameters is evaluated.