Measurement of dynamic large-strain deformation maps using an automated fine grid technique

Automatic analysis of the dynamic deformation of a fine grid ruled onto a specimenʹs surface has allowed whole-field rncasurerpent of both in-plane displacement components. A high-speed camera was used to capture images of impacts at velocities of over 500 m/s. The Fourier transform method and phase unwrapping were used to calculate planes of phase coordinates which deform with the specimen. An iterative search algorithm yields the displacements directly by searching for the shifted location of each set of phase coordinates in the image of the deformed specimen. This paper describes the application of a previously proven analysis technique to dynamic deformation. Simple sample preparation and experimental operation make this technique ideal for the dynamic regime.