Quantitative stress measurement of elastic deformation using mechanoluminescent sensor: An intensity ratio model

The mechanoluminescent (ML) sensor is a newly developed non-invasive technique for stress/strain measurement. However, its application has been mostly restricted to qualitative measurement due to the lack of a well-defined relationship between ML intensity and stress. To achieve accurate stress measurement, an intensity ratio model was proposed in this study to establish a quantitative relationship between the stress condition and its ML intensity in elastic deformation. To verify the proposed model, experiments were carried out on a ML measurement system using resin samples mixed with the sensor material SrAl₂O₄:Eu²⁺, Dy³⁺. The ML intensity ratio was found to be dependent on the applied stress and strain rate, and the relationship acquired from the experimental results agreed well with the proposed model. The current study provided a physical explanation for the relationship between ML intensity and its stress condition. The proposed model was applicable in various SrAl₂O₄:Eu²⁺, Dy³⁺-based ML measurement in elastic deformation, and could provide a useful reference for quantitative stress measurement using the ML sensor in general.