Assessment of non-adiabatic behaviour in thermoelastic stress analysis of small scale components

Abstract

The classical thermoelastic equation and thegeneralized heat conduction equation are developed to dealwith a non-adiabatic response in thermoelastic stressanalysis. A FE simulation procedure is set up to solve theheat conduction equation over a range of loading frequencies.A small disc (20 mm diameter) loaded under threepointdiametric compression is used to examine the effectof in-plane heat conduction. As the disc has regions of zero,moderate and high stress gradients it is an ideal componentfor this analysis. A regime is developed that provides abasis for an assessment of the nature of the response andallows a minimum loading frequency to be identified sothat adiabatic behaviour is obtained. This validity of thisapproach is demonstrated on steel disc of 20 mm diameter.A special loading device has been designed to obtain thethree-point loading and a recently introduced Instron Electropuls test machine is used to achieve the high levelsof cyclic loading required for the adiabatic conditions