Experimental analysis of the Portevin Le Chatelier effect by means of full field non contact techniques

Abstract

Strain related phenomena in materials showing the Portevin Le Chatelier (PLC) effect are investigated when subjected to loading conditions both in elastic and in plastic field. Two experimental techniques for strain measurements are compared, thermography and optical strain measurement, both non contact, non destructive and full field. Two materials have been tensile tested with several test speeds. Each specimen has been observed and test evolution has contemporaneously been acquired with both video and thermotracer. Each test has been repeated several times. Aim of this research is to investigate how these experimental techniques may quantitatively describe the above described phenomena. Experimental data are useful to calibrate models describing the mechanical behaviour of materials (i.e. constitutive laws, damage models, etc.) and to focus phenomena which take place during load and corresponding strain phases.