Dynamic visualization of stress distribution on metal by mechanoluminescence images

We have successfully demonstrated that the stress distribution of a metal material can be directly displayed by coating the surface of test objects with an upgraded strong mechanoluminescence (ML) material of SrAl2O4:Eu (SAO). In this paper an aluminum plate with the SAO sensing film was applied to experimental analysis of stress concentrations. And the comparison with a numerical analysis showed that the ML intensity of SAO sensing film correlates linearly with stress on metal surface and the observed real-time ML images quantitatively reflect stress concentration. This novel visualisation technique can be applied to view stress concentration in various fields such as modelling, manufacturing and demonstration of industrial products as well as to point out danger areas in structural objects such as pipelines and bridges.