Abstract
Phase-shifting digital holography is a suitable method for measuring very small displacement. An optical system which can measure surface displacement was built and the validity was verified for a fixed disk under a concentrated load perpendicularly to the surface at its center. To obtain the components of 3D strain, the components of displacement obtained by holography have to be differentiated spatially. The authors adopted the minimum spanning tree technique for the process to get continuous distribution of displacement. The results showed a good agreement between theoretical and experimental analyses.
