International Journal for Numerical Methods in Engineering. Vol. 72, No. 8, pp. 893-923, 2007
Z. (Jenny) Zhang , G.H. Paulino
Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Newmark Laboratory, 205 North Mathews Avenue, IL 61801, U.S.A
W. Celes
Tecgraf/PUC-Rio – Computer Science Department, Ponti.cal Catholic University of Rio de Janeiro, Rua Marquês de São Vicente 225, Rio de Janeiro, RJ 22450-900, Brazil
Abstract
Abstract: Dynamic mixed-mode fracture phenomena are investigated by means of a computational fracture mechanics approach that enables arbitrary crack evolution by incorporating special interface elements. An initially rigid cohesive zone model (CZM) is employed to characterize the fracture process, which necessitates adaptive insertion of interface elements and intensive bookmarking of mesh modification information. A recently developed topological data structure representation is employed to enable unified, fast and robust manipulation of evolving mesh information when extrinsic cohesive elements are inserted adaptively. Application of the numerical approach is illustrated through a pre-notched concrete three-point bending beam example. The beam experiments indicate different crack evolving patterns depending on mode mixity factor for different initial notch positions. This phenomenon is studied using both two-dimensional and three-dimensional numerical simulations, with a focus on the latter. Mesh dependency issue is particularly important for three-dimensional simulations, which is investigated in detail. The simulation results compare reasonably well with experimental observations, and demonstrate that extrinsic CZM can be successfully applied in three-dimensional fracture analysis with careful attention to mesh quality.
Keywords: Finite element method, Three-dimensional, cohesive zone model (CZM), dynamic fracture, three-point-bending beam, extrinsic, topological data structure.