Analysis of strain state prismatic samples for mechanical testing of the biaxial stretching method digital image correlation

Abstract

The paper deals with the experimental-calculated analysis of the deformed state of a prismatic type sample for mechanical laboratory tests designed to evaluate the strength of a material under a biaxial stress state. A description is given of the advantages of the deformation scheme of this sample, which contributes to a reduction in the technical requirements for the test machines used for performing the test procedures. The distribution of deformation fields of the prismatic sample surface studied is obtained by processing the speckle images of the on-board experiment by the method of correlation of digital images in the Vic-3D system, at the stage of elastic deformation. Their comparison with the results of numerical simulation by the finite element method at control points of the surface of the deformed sample is performed. The discrepancy between the results of the full-scale experiment and the given numerical simulation at the control points did not exceed 14%. Conclusions are formulated for the subsequent use of the results obtained.