Mesoscale measurement of strains by analyzing optical images of the surface of loaded solids

Abstract

UDC 004.932 P. S. Lyubutin and S. V. PaninAn algorithm for estimating the strains in solids at the mesoscale level, which is based on constructing fields of displacement vectors and calculating strain components, is studied and tested. Verification of the method is performed by comparing the analytically calculated strain components with experimental data obtained on the basis of model images and images recorded by a TOMSC optical TV measurement system during tension of polymer samples. The estimates of the strain components obtained by a correlation analysis of images are shown to be in good agreement with the results of analytical calculations for known loading parameters and sizes of the images under analysis. The results of the study confirm that the TOMSC system can be used to estimate local strains by processing images of the surface of loaded samples of materials.

Structural Aspects of Zr⁺ Ion-Beam Surface Modification and Mechanical Properties of 12CrMoV Steel

“…Urgent Problems of Up-to-Date Mechanical Engineering The nature of the gradual exhaustion of the plasticity of a material under static tension was previously shown in the papers of academician V.E. Panin where the behavior of a loaded solid was compared with elastic vibration of a string [10], and the formation of a neck was representing exactly as the process of gradually reducing the size of the gauge length of the specimen where this "elastic-plastic wave of a local curvature" can propagate [11]. Development of deformation in the irradiated specimen was of a slightly different nature.…”

Application of meso- and fracture mechanics to material affected by a network of thermal fatigue cracks

“…Specimens were tested under static tension; in doing so the stress-strain state in a loaded specimen is similar to that being experienced by steel roller of a continuous billet casting machine (CBCM) under operating loading. Television optical-measurement system TOMSC [8] was used to study the peculiarities of their deformation behaviour at meso-and macroscale.…”

Fatigue life enhancement by irradiation of 12Cr1MoV steel with a Zr+ ion beam. Mesoscale deformation and fracture

“….or optical estimation of strains in fatigue tests and characterization of deformation reliefs, images of the specimen surface were taken with a Canon EOS 550D camera. .or construction of displacement vector fields and their subsequent translation to strain components, we used the TOMSC television-optical measuring complex and special software [7]. .or strain estimation, we calculated the normalized shear strain intensity [8].…”