Deformation and failure characteristics of sandstone under uniaxial compression using distributed fiber optic strain sensing

This paper investigates the deformation and fracture propagation of sandstone specimen under uniaxial compression using the distributed fiber optic strain sensing (DFOSS) technology. It shows that the DFOSS-based circumferential strains are in agreement with the data monitored with the traditional strain gage. The DFOSS successfully scans the full-field view of axial and circumferential strains on the specimen surface. The spatiotemporal strain measurement based on DFOSS manifests crack closure and elastoplastic deformation, detects initialization of microcrack nucleation, and identifies strain localization within the specimen. The DFOSS well observes the effects of rock heterogeneity on rock deformation. The advantage of DFOSS-based strain acquisition includes the high spatiotemporal resolution of signals and the ability of full-surface strain scanning. The introduction to the DFOSS technology yields a better understanding of the rock damage process under uniaxial compression.