Estudio experimental de la incidencia de la temperatura en lecturas de deformaciones obtenidas a partir de galgas extensiométricas

Abstract

This work aimed to study the possible deviation of readings in strains obtained from geometrically and structurally defined specimens depending on working temperature intervals within a range of environmental conditions (20 - 70ºC) through the use of flat strain gauges and rosette type. To obtain the deformations, two specimens with defined geometry and configuration were submitted, first a metal specimen of A304 steel in a cantilever to get bending and a metallic sample of A304 steel with an L configuration to obtain combined efforts which are generated by loads defined by the research team, the experimental temperature conditions were supplied by a thermal control chamber that was designed by the members of the present work using the QFD methodology, which was built and tested in order to communicate to the measurement environment of the gauge a stable temperature and also provide a constant rate of thermal increase in 10°C. Deformations obtained were interpreted through the LabVIEW software; used as an interface between the user and the gauge readings—these data allowed to get a temperature behavior curve versus deformation. Thanks to the extended Euler formula, they were contrasted through a theoretical analysis of the sample deformation and the nature of the load carried by thermal variations. Finally, to determine the incidence of the effects of temperature on the element under study, the principal and theoretical stresses shown as stress states were obtained. It allowed the generation of thermal and environmental compensation factors for the different practices proposed. It is recommended to apply a new model of experimentation for other materials and specimen configurations to obtain the incidence of temperature in strain gauge readings.