Publications

Impact of Elastic Moduli in Tension and Compression in Geomaterials

McCarty, Sean M.; Newell, Pania N.

Predicting the long-term integrity of caprock is essential for determining the viability of carbon sequestration. Accurate prediction requires incorporating knowledge about small- scale, subcritical fracture and how they contribute to developing micro and macro-cracks. Tests such as short rod, notched three-point bending (N3PB), cylinder splitting, double torsion, etc. are used to determine the physical characteristics of material. Unlike other materials such as metals, geomaterials have different moduli in tension than compression. This study compares the effects of separate tension and compression moduli on simulations in Abaqus for the N3PB test. Previous models of N3PB created by Rhinehart et al. [8] and Borowski [6] have struggled to create results that accurately portrayed experimental results. Borowski [6] found that previous models with only one value for Young's modulus improved when two moduli were used though it was difficult to determine regions of tension and compression prior to simula- tion. This study develops an Abaqus subroutine written in Fortran to dynamically reassign material properties as the simulation progresses and produces simulation results capable of much better replication of experimental data. However, the accuracy of the model heavily depends on accurate determination of the Young's modulus in tension.