Impact of Stress-Induced Rock Damage on Elastic Symmetry: From Transverse Isotropy to Orthotropy

Abstract In this article we explore the change in elastic symmetry and anisotropy of two geological materials with stress-induced damage. Two independent uniaxial deformation experiments on layered natural geomaterials, a shale sandstone, support analysis. Both samples were loaded along their bedding planes at constant strain rate up to mechanical failure. During deformation, an array ultrasonic P- S-wave transducers employed monitor evolution velocities beyond sample We report here impact load applied parallel plane transversely isotropic sandstone samples. Based considerations analyse whether resulting damage preserve original transverse isotropy rock prior loading, or lead orthotropy (orthorhombic symmetry). Our results show that retained initial stages loading/damage. However for more anisotropic main failure mode was splitting planes. contrast failed shear inclined plane. addition, experimental data are further analysed using continuum mechanics identify general fourth order tensor during loading. found highest variable $$D_{11}$$ D 11 $$D_{55}$$ 55 sample. The next variables related ( $$x_2$$ x 2 – $$x_3$$ 3 plane) symmetry: $$D_{23}, D_{32}, D_{44}$$ 23 , 32 44 . obtained less brittle harder interpret due mixed fracturing present.