Cross-scale mechanical characterization of shale and marlstone rocks from nanoindentation, microindentation, and triaxial tests: implications for mechanical upscaling from micro to macro scale

One is to obtain the clustering analysis results from indentation data of various shales and marlstone (Figure 9). One is to obtain the deviatoric stress‒strain curves at various confining pressures (0 MPa, 20 MPa, and 40 MPa) for all the samples (Figure 12).

One is to obtain the comparison between the results of predicted moduli with the static Young's modulus and the relative errors (Figure 14).