SIMULTANEOUS MEASUREMENT OF STRESS AND STRAIN FOR TRANSPARENT SPECIMENS SUBJECTED TO CONCENTRATED LOAD

In this paper, a combined measurement method combining digital gradient sensing (DGS) and digital image correlation (DIC) is proposed, which can realize simultaneous stress and strain measurement of transparent samples subjected to concentrated load under plane stress state. The fluorescent speckles of blue and red were prepared on the surface of transparent sample and speckle plate respectively, and then 3CCD camera was used to separate the fluorescent speckle of specific spectrum on the sample and speckle plate, so as to realize the independent imaging of the two speckle images. The strain and stress gradient fields of the transparent sample can be obtained by calculating separately. The feasibility of this method is verified by the comparison between the experimental results and the analytical values of the half-plane concentrated force loading experiment.