Discrete vs smeared crack models for concrete fracture: bridging the gap

Abstract

SUMMARYDiscrete and smeared crack models for concrete fracture are discussed in a historical perspective. It is argued that these two computational approaches, originally conceived as very different, can be brought together by exploiting the partition-of-unity property of finite element shape functions. The cohesive segments method, which exploits this partition-of-unity property, exhibits advantages of both the discrete and smeared crack approaches, and is capable of describing the transition from distributed micro-cracking to a dominant crack. The versatility of the cohesive methodology is shown by incorporating water diffusion and ion transport into the formulation.

An isogeometric approach to cohesive zone modeling

“…As can be seen, the response for the intermediate mesh practically coincides with that of the fine mesh, indicating that an accurate solution is obtained using the intermediate mesh. The results are in excellent agreement with these found in [36] where 2079 linear quadrilateral elements were used. As can be observed from the contour plot in Figure 16, a crack nucleates at the notch upon loading and runs downward into the adhesive layer.…”

“…The second numerical experiment we consider is the double cantilever beam as introduced in [36]. The two cantilever beams shown in Figure 11 are connected by an adhesive layer and are loaded by a force P at the bottom right tip of the lower beam.…”

“…In order to reproduce the simulation in Ref. [36], the crack is forced to nucleate from the center of the notch.…”

Use of negative stiffness in failure analysis of concrete beams

“…Due to the approximate nature of the smeared cracking method, some of the behaviour details are inevitably lost. For more details of these two methods see Borst et al [30].…”

A Continuous–Discontinuous Approach to Simulate Heat Transfer in Fractured Media

“…This observation stimulated the development of so-called discrete fracture flow models, where the geometry of the fracture network is explicitly modeled Carmeliet et al 2004). The discrete model can be coupled to the continuum transport model by employing interface elements (Segura and Carol 2008), by introducing a mass source term along the length of a discrete fracture (Therrien and Sudicky 1996;Roels et al 2006) or by inserting a strong (de Borst et al 2004;Alfaiate et al 2010) or a weak (Réthoré et al 2007(Réthoré et al , 2008) discontinuity in the pressure field.…”