Method for measuring transient out-of-plane deformation during impact

Abstract

There is no standard methodology to measure the transient deformation of a material under impact. High speed photography can be used to capture the deformation but is limited to one projected plane of view. The knowledge of the entire deformed field and its time history of a material is of great interest to many researchers. This investigation will employ a shadow moiré and high speed photography method by which the entire deformation history of the surface can be measured. Shadow moiré is a technique to measure out-of-plane displacement using a linear grating and the interference fringe patterns that occur during deformation are recorded using a high speed camera. The recorded fringe patterns are enhanced and processed with a data analysis code to map out the history of the displacement field of the entire rear surface of the target during the impact.