Advances in nonadiabatic thermoelastic stress analysis on helicopter components

Thermoelastic Stress Analysis (TSA) is a powerful tool for the measurement of stress in components under fatigue test. TSA allows for the attainment of reliable quantitative results only if heat diffusion in the component is negligible. However, in real fatigue tests of aluminium alloy components, the high thermal diffusivity allows adiabatic conditions to reached only for very high frequencies of the loads applied. A correction procedure recovering the adiabatic temperature from data obtained in non adiabatic conditions have been developed and subsequently ameliorated allowing to obtain quantitative results in good accordance with classical measuring techniques, like strain gauges.