Quantification of Fracture Interaction Using Stress Intensity Factor Variation Maps. Issue 10 (21st October 2017)

• Record Type: Journal Article
• Authors: Thomas, Robin N.; Paluszny, Adriana; Zimmerman, Robert W.
• Is Part Of: Journal of geophysical research. Volume 122:Issue 10(2017)
• Page Start: 7698
• Page End: 7717
• Publication Date: 2017-10-21
• Subjects: fracture interaction -- stress intensity factor -- finite element -- unstructured mesh -- fracture; Geomagnetism -- Periodicals; Geochemistry -- Periodicals; Geophysics -- Periodicals; Earth sciences -- Periodicals; 551.1
• DOI: 10.1002/2017JB014234
• Languages: English
• ISSNs: 2169-9313

Abstract

Abstract: Accurate and flexible models of fracture interaction are sought after in the fields of mechanics and geology. Stress intensity factors (SIFs) quantify the energy concentrated at the fracture tips and are perturbed from their isolated values when two fractures are close to one another. Using a three‐dimensional finite element fracture mechanics code to simulate static fractures in tension and compression, interaction effects are examined. SIF perturbations are characterized by introducing three interaction measures: the circumferential and maximum SIF perturbation provide the "magnitude" of the effect of interaction, and the amplification to shielding ratio quantifies the balance between increased and decreased SIFs along the tip. These measures are used to demonstrate the change in interaction with fracture separation and to find the separation at which interaction becomes negligible. Interaction maps are constructed by plotting the values of the interaction measures for a static fracture as a second fracture is moved around it. These maps are presented for several common fracture orientations in tension. They explore interaction by highlighting regions in which growth is more likely to occur and where fractures will grow into nonplanar geometries. Interaction maps can be applied to fracture networks with multiple discontinuities to analyze the effect of geometric variations on fracture interaction. Key Points: Fractures are modeled using 3‐D finite element simulations Three measures are used to quantify the amount and type of interaction a fracture experiences Interaction maps demonstrate how interaction varies with fracture spacing and orientation