Robust Polyhedral Finite Element Methods for Pervasive Fracture Simulations

University Of California-Davis, Davis CA

Investigators

Abstract

The research objective of this project is to develop a robust computational fracture tool to simulate pervasive three-dimensional fracture processes in materials and structures. Under extreme loading conditions, the extent of fracture is pervasive in materials and structures - multitude of cracks can nucleate, coalesce, branch, and propagate in arbitrary directions. Cohesive tetrahedral finite elements (4 facets per element) are presently the method-of-choice for such complex simulations, but show mesh-dependencies in such fracture simulations. Due to the presence of many more facets than in a tetrahedral mesh, a polyhedral mesh provides more pathways for crack formation and growth. Issues pertaining to weak convergence (fragment mass distribution, crack path) in the numerical simulations will be examined, and verification studies will be conducted to assess convergence of the fracture simulations. These novelties in a computational fracture simulation tool can overcome the existing limitations of deterministic tetrahedral finite element meshes and thus pave the way for a breakthrough in this key area of computational fracture research. A successful outcome in this project will change the way the largest and most complex failure simulations are done, and open the way for many new applications of polyhedral finite element methods. The potential impact of this project will be significant in physics-based fracture modeling: for example, brittle and ductile fracture of metallic materials, biomaterials, geophysics, rock mechanics, CO2 sequestration, and fluid-driven fractures (hydraulic fracturing) are pertinent applications. The educational plan focuses on the integration of the research within graduate curricula on advanced finite element methods and fracture. The external collaboration with Dr. Bishop at Sandia National Laboratories will enable the new methods developed to be incorporated in large-scale software codes at the laboratory, and also provide an enriched summer internship opportunity for graduate students to work on topical areas at the forefront in computational failure mechanics.