Finite Element Analysis And Research Of Material Tensile Experiment Based On DIC

Digital Image Correlation(DIC)measurement method is a typical method in the non-contact measurement category,which has the advantages of simple experimental setup and sample preparation,low measurement environment requirements,and high measurement sensitivity and resolution.It cooperates with image acquisition equipment with high spatial resolution and high temporal resolution,which can realize stress-strain measurement in more complex situations.Compared with traditional measurement methods,it has the advantages of process analysis.In recent years,the development of digital image correlation measurement methods has become more and more mature,and there are many successful examples in the measurement of flat samples,but at present,there is no relatively mature digital image correlation system software and hardware manufacturers in China,more companies are agents of foreign companies such as Correlated Solutions,Inc.(CSI)in the United States and Correlated Solutions Europe(CS-EU)in Germany.The hardware modules and software modules they sell are expensive.Aiming at this situation,it is of vital economic value to study the related measurement principle of digital image and realize its calculation principle and measurement function through programming.In this paper,Q235 low carbon steel standard bar with an aspect ratio of 10 was selected as the sample,and the static load tensile test at room temperature was carried out on it by the MTS testing machine.The speckle image sequences of the specimens were acquired during the stretching process using the plane-field deformation optical measuring instrument and VIC-Snap provided by CSI.After image processing of the acquired image sequence,the problem of partial reflection of the sample was reduced to a certain extent.The time synchronization function of MTS and DIC was used to determine the state of the surface speckle of the sample at different times,and the speckle image sequence was sampled according to the characteristics of the different stages of the sample.The sampled speckle images were analyzed by using VIC-2D provided by CSI and MATLAB APP designed according to the principle of digital image correlation,and the calculation results were compared according to the four typical stages of the sample.The results show that the average error of the strain calculation results of the MATLAB APP is 5.8346%,and the strain curve also consistent within the allowable error range,so the APP can realize the main functions of the VIC-2D software.