Uncertainty in the determination of elastic modulus by tensile testing

Abstract

The paper presents the results of theoretical and experimental research related to the uncertainty in the elastic modulus measurement on different types of tensile testing devices and their comparison. Factors that affect the uncertainty in the measurement of the elastic modulus were defined. Analytical limits of the uncertainty in the elastic modulus, i.e. the limits of “acceptable” uncertainties, were determined. The mean values of the uncertainties in the elastic modulus are 1.97% on a conventional tensile testing device with an extensometer and 1.56% on a small laboratory tensile testing device. In the region of lower forces and small elongations, the uncertainty in the elastic modulus measurement has higher values, which is primarily caused by the imperfections of measuring instrumentation.