Smeared Crack analysis Using a Generalized Fictitious Crack model

he fictitious crack model is extended so that it includes the effect of crack shearing. By the introduction of the so-called equivalent length, it is possible to establish a smeared version of the fictitious crack model. The equivalent length is a purely geometrical quantity that depends entirely on the size and form of the element and on the crack direction. A realistic modeling of crack shearing is obtained, and the smeared constitutive relations are objective with respect to both loading normal to the crack plane and loading tangential to the crack plane. The existence of multiple cracks is considered, and a consistent theory for unloading and possible closure of the cracks is presented. FE calculations of a concrete specimen using four different element types demonstrate the objectivity of the theory even when distorted meshes are used.