Estimating the Specific Heat Loss from Temperature Measurements in Tension-Tension Fatigue: Theory and Experiments

An analytical framework was developed to correlate the intrinsic dissipation to the second harmonic of the temperature signal evaluated by means of the Fourier transform, in the case of tension-tension fatigue. The theoretical model assumes internal adiabatic conditions and that the elastic-plastic mate-rial obeys a Ramberg–Osgood law. It was found that the intrinsic dissipation is correlated to the second harmonic of the temperature signal by means of a parameter (the β parameter) that depends on the cyclic hardening exponent n′. Eventually, the theoretical model was applied to data obtained by step-wise fatigue tests carried out on plain specimens made of C45 normalized steel