ASCE - Journal of Engineering Mechanics
K. Park , G.H. Paulino and J.R. Roesler
Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Newmark Laboratory, 205 North Mathews Avenue, IL 61801, U.S.A.
Abstract
Abstract: This multiscale study employs the initial and total fracture energy through a new virtual internal pair-bond (VIPB) model. The proposed VIPB model is an extension of the traditional virtual internal bond (VIB) model. Two different types of potentials, a steep short-range potential and a shallow long-range potential, are employed to describe the initial and the total fracture energies, respectively. The Morse potential function is modified for the virtual bond potential so that it is independent of specific length scales associated with the lattice geometry. This feature is incorporated in the VIPB model, which uses both fracture energies and cohesive strength. With respect to the discretization by finite elements, we address the element size dependence in conjunction with the J-integral. Parameters in the VIPB model are evaluated by numerical simulations of a pure tension example in conjunction with measured fracture parameters. We also validate the VIPB model by predicting load versus crack mouth opening displacement curves for geometrically similar specimens, and the measured size effect.
Keywords: Virtual internal bond (VIB) model, Virtual internal pair-bond
(VIPB) model, Morse potential, crack propagation, size effect, quasi-brittle materials, multiscale modeling