Image brightness analysis as a tool for strain measurement in photoelastic compression tests on PDMS granulate

The paper to which the dataset is related presents the behavior of samples made of self-manufactured polydimethylsiloxane (PDMS) grains in a photo elastic uniaxial compression test. They were subjected to a load-unload cycle according to several scenarios (Fig_26).To study the potential relationship between the uniaxial strain calculated based on the change in a sample’s height and the corresponding optical parameters, a parallel analysis was conducted using the average image brightness. It led to the proposal of standardized strain and brightness parameters (Fig_32).On this basis, a unique relationship has been found between normalized uniaxial strain and normalized relative average image brightness, encompassing both loading and unloading regimes (Fig_32).