Measurements of material anisotropy by ultrasonic technique

Many geological materials when subjected to sequences of loading, unloading and re-loading, experience induced anisotropy, due to factors such as microstructural changes and damage. Herein, an experimental procedure has been developed, which enables multi-axial mechanical (destructive) and ultrasonic (non-destructive) testing of geologic materials. The paper describes the experimental scheme, data acquisition system and test results on a cemented sand under hydrostatic stress path of loading, unloading and re-loading. Examination of the stress-strain, stress-velocity and stress-attenuation data provides insight into the material anisotropy, its quantification, and correlation between mechanically defined anisotropy and non-destructively measured anisotropy. -Authors