FRAFE: A Finite-Element Program for Stress Analysis in Fractured Rocks

摘要

FRAFE is a static two-dimensional elastic finite-element program for analysis of fractured rock. It employs four-node rectangular elements with which Mode I stress-intensity factors can be calculated. Finite elements near the edge of the grid can be expanded by an automatic zoning to reduce boundary effects. Equation solving is achieved using the Incomplete Cholesky Conjugate Gradient relaxation technique. Fractures can change direction only in 45-degree increments. The program has been applied to several analyses in fractured rock such as: surface deflection due to layering with a vertical crack; crack behavior near a bonded interface; effect of multiple cracks on interface penetration; perturbation of a stress field by the presence of lenses; and hydraulic fracturing in a nonuniform stress field. (ERA citation 08:039477)