Modeling of Sand Triaxial Specimens under Compression: Introducing an Elasto-Plastic Finite Element Model to Capture the Impact of Specimens’ Heterogeneity

This paper follows up on a series of reference papers that inspired MDPI’s Topic “Stochastic Geomechanics: From Experimentation to Forward Modeling”, where global and local deformation effects sand specimens are fully described from high-resolution boundary displacement fields, as supported by comprehensive experimental database (which includes varying degrees specimen’s heterogeneity) is available the scientific community for further study. presents an elasto-plastic comparative analysis different finite element models reproducing specimen heterogeneity configurations follows: loose, dense, half-dense half-loose specimens. The conditions these specimens’ were simulated with axisymmetric model. To characterize stress-strain response obtained experiments, constitutive model strain-hardening softening laws was adopted reproduce mechanistic response. An expert-based calibration numerical accounted both making use observations captured triaxial point sensors (i.e., axial force displacement) 3D digital image correlation fields). Results show predictions proposed in good agreement observations, responses. combined calibrate sets basis more parameterization process. For first set, three experiments assumed homogeneous materials. While dense loose showed field prediction layered identified limitations heterogeneous configurations. Afterward, second set compared analyzed implementing model, showing significantly better after implementation which accounts transition zone between upper lower segments).