Al 인장시험편의 디지털 이미지상관관계를 이용한 변형율 측정에 관한 연구

Abstract

Abstract

A digital image correlation(DIC) method is a whole-field measurement technique that acquires surface displacements and strains from images information which characterized a random speckle as intensity grey levels. Recently years, this DIC method is being developed and used increasingly in various reserch. In this study, we tried to apply to aluminum alloy(Al6061-T6) using DIC method and strain gauge. DIC results demonstrated the usefulness and ability to determine a strain. The test specimen used in this study was an aluminum alloy(Al6061-T6, thickness:1mm). For a strain measurement, a strain gauge was attached at the center of a specimen. A specimen was lightly sprayed with a white paint and a black dot pattern was sprayed on its fully dried white surface to obtain a random speckle. The experimental apparatus used to perform the tensile test consisted of universal dynamic tester(5kN; T.O. Co.) under displacement speed of 0.5, 1.0 and 3.0mm/min. A Model 5100B Scanner(V. Co.) used to obtain a strain. A CCDcamera connected to a PC uses to record the images of the specimen surface. After acquisition, the images were transferred to PC where the DIC software was implemented. An acquired image was evaluated by the DIC program. The following conclusions could be drawn from this study. (1) DIC method for displacement and strain was suggestes and it results show a good consistent remarkably. DIC results demonstrated the usefulness and ability to determine surface strain was better than by using classical mesurements. (2) The strain field measurement using a DIC is so useful that it can be applied to map strain distributions at a full area. (3) DIC method can evaluate a strain change so it can predict a location of fracture. The findings of the investigation suggest that the DIC method is an efficient and reliable tool for full-field monitoring and detailed damage characterization of materials.