초록
Electronic Speckle Pattern Interferometry(ESPI) using the Model 95 Ar. laser, a video system and an image processor was applied to the in-plane displacement measurements. Unlike traditional strain gauges or Moire method, ESPI method requires no special surface preparation or attachments and can be measured in-plane displacement with no special surface preparation or attachments and can be measured in-plane displacement with no contact and real time. In this experiment specimen was loaded in parallel with a loadcell. The specimen was the cold rolled steel sheet of 2mm thickness, which was attached strain gauges. The study provides an example of how ESPI have been used to measure strain displacement in this specimen. The results measured by ESPI compare with the data which was measured by strain gauge method in tensile testing.