Fringe analysis software: Application to velocity measurement in dynamic compression experiment

Optical technique such as laser Doppler interferometry is quite popular for non contact measurement and has been applied in free surface velocity measurement in dynamic compression experiment. In this technique the information of measured physical quantity such as surface velocity is encoded in the phase of a fringe pattern. Fringe analysis software extracts the phase from the fringe pattern. The present work reports the development of robust fringe analysis software for complete time history of free surface velocity measurement from recorded fringe signals. The analysis code has been verified by generating free surface velocity history from different simulated fringe profiles. The effects of various measurement imperfections are also studied and corrective measures are coded in the software. Finally, software is validated by analyzing the plate impact experimental data of Al-2024T4 material. Good agreement was obtained between analysis result of experimental data and published data.