A method for constructing the bilinear tension softening diagram of concrete corresponding to its true fracture energy

Abstract

For the analysis of cracked concrete structures using the fictitious crack model two fracture properties of concrete are required, namely its true specific fracture energy G F and the corresponding tension softening relation ó(w). In a recent paper, the authors proposed a simple method for the determination of the true specific fracture energy of a concrete mix. In this paper a method is proposed based on the concept of a non-linear hinge for constructing a bilinear approximation of the tension softening relation consistent with the true specific fracture energy G F . The parameters of this bilinear approximation are inferred in an inverse manner. It is shown that this inverse identification procedure predicts accurate bilinear softening relations of concrete mixes tested in three-point bend and wedge-splitting modes.

Incremental‐secant modulus iteration scheme and stress recovery for simulating cracking process in quasi‐brittle materials using XFEM

“…We now study the beam in Section 4.1 with the properties and a bilinear softening law obtained by Abdalla and Karihaloo [31] for a real normal strength concrete. The material properties are E = 36.9 GPa, = 0.2 and the bilinear softening law (Figure 7) is described by …”

Asymptotic fields at frictionless and frictional cohesive crack tips in quasibrittle materials

“…They also illustrated the predictive capability of the cohesive zone model for concrete, glassy polymer and steel. Recently, have proposed a simple method for determining the true specific fracture energy of concrete and also a method [Abdalla and Karihaloo 2004] for constructing a softening curve corresponding to this energy. In the most widely used standard formulation of the cohesive crack model for quasibrittle Keywords: asymptotic field, cohesive crack tip, Coulomb friction, quasibrittle material, cohesion-separation laws.…”

Asymptotic fields at the tip of a cohesive crack

“…Chandra et al 2002). Recently, Karihaloo et al (2003) have proposed a simple method for determining the true specific fracture energy of concrete and also a method (Abdalla and Karihaloo 2004) for the inverse identification of a softening curve corresponding to this energy.…”