SMEARED CRACK APPROACHES--MATERIAL MODELING

Since the smeared crack concept has proved to be very attractive when used in the finite-element fracture analysis, many different material models have been put forward. The majority of these models, usually known as a single or multiple crack models, are based on a linear elastic material constitutive law coupled in series with a softening crack-bridging law. The crack-bridging law on the plane where tensile fracture occurs, although defined in terms of stresses and strains, is basically the same vectorial relation used in the discrete crack approach. These models yield some problems due to the nonconsistency of the basic hypothesis and sharp discontinuities in the resulting material behavior. In this paper some of these problems are analyzed and compared with concepts and results coming from the nonlocal microplane material model. Numerical studies on the material and finite-element level using both approaches are reported.