A study of the thermal behaviour of a specimen during fatigue

A steel specimen (XC 10), submitted to fatigue by alternating symmetrical torsion, gives rise to heat dissipation, which is a function of the amplitude of the applied forces.The relationship between the amplitude of the applied forces and the quantity of heat dissipated was measured while a specimen underwent fatigue testing (E_n curves).The results appear to show that this relation is not identical for similar specimens at the beginning of the tests, initial state which is assumed to correspond to something like a “virgin state”, but that there is a convergence of the E_n curves as rupture is approached.