International Journal of Plasticity, special issue on "Inelastic Response of Multiphase Materials," Vol. 21, No. 6, pp. 1195-1254, 2005
Z. 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.
Abstract
This work investigates dynamic failure processes in homogeneous and Functionally Graded Mate-
rials (FGMs). The failure criterion is incorporated in the Cohesive Zone Model (CZM) using both a
finite cohesive strength and work to fracture in the material description. A novel CZM for FGMs is
explored and incorporated into a finite element framework. The material gradation is approximated at
the element level using a graded element formulation. Examples are provided to verify the numerical
approach, and to investigate the influence of material gradation on crack initiation and propagation
in mode-I as well as in mixed-mode fracture problems. The examples include spontaneous rapid
crack growth in homogeneous and FGM strips, dynamic crack propagation in actual monolithic and
epoxy/glass FGM beams (three-point bending) under impact loading, and mixed-mode crack propagation
in pre-cracked steel and graded plates.
Keywords: Finite element method, graded finite element, functionally graded material (FGM),
graded composites, intrinsic cohesive zone model (CZM), dynamics, mixed-mode fracture.