Distinct Element Modeling of Uniaxial Compression Tests of Tuff-like Lithophysal Material; Using Voronoi Tessellation System

摘要

Uniaxial compression tests on Hydro-StoneTB (R) porous cubes were numerically modeled using a distinct element program (UDEC) for two-dimensional geological material simulation. Under uniaxial compression, numerical square models with varying void porosity and geometry, identical to an experimental testing, were simulated. The open-ended longitudinal openings in the experimental specimens, cubic porous Hydro-StoneTB (R), were of various forms, sizes, uniformity, and distributions. UDEC's Voronoi tessellation joint generator was used to simulate the material of the experimental specimens as an assembly of discrete units interacting along their boundaries. The results showed that the numerical results from the two-dimensional numerical analysis utilizing the discrete element method, UDEC program, were consistent with the experimental data. However, when compared to the experimental values, the numerical analysis produced conservative values for both uniaxial compressive strength and Young's modulus due to the modeling of a three-dimensional material in a two-dimensional planar strain. Furthermore, regardless of void porosity or geometry, the tension (axial splitting) failure mode is the dominating failure mode of rock-like materials including voids, similar to the experimental results. It was also demonstrated that using a power relationship, two-dimensional numerical data can be converted to three-dimensional experimental results.