Real-time measurement on deformation fields of notched samples under impact tension

In this paper, a real-time and in situ optical measuring system is reported to observe high-velocity deformations of samples subjected to impact loading. The system consists of a high-speed camera, a He-Ne laser, a frame grabber, a synchronization device and analysis software based on digital correlation theory. The optical system has been adapted to investigate the dynamic deformation field and its evolution in notched samples loaded by an split Hopkinson tension bar, with a resolution of 50μm and an accuracy of 0.5μm. Results obtained in experiments are discussed and compared with numerical simulations. It is shown that the measuring system is effective and valid.