Numerical modeling of crack propagation using zero-thickness interfaces elements and configurational mechanics

The prediction of crack trajectories is one of the major challenges of existing numerical methods for the mechanical behavior of concrete and other quasi-brittle materials. For this purpose, this paper describes a methodology based on the use of zero-thickness interface elements equipped with a fracture-based constitutive law, combined with Configurational Mechanics theory. In the implementation developed, interface elements, initially inserted in between standard continuum elements, become realigned during the fracture propagation process on the basis of the so-called “configurational forces”, which represent the gradient of the total elastic energy of the domain with respect to the initial nodal position. In this way, and unlike most methods used in crack propagation that are based on local criteria such as maximum tensile stress, in the proposed method the crack configuration that is obtained approaches a global energy minimum for the structure or domain. The performance of the method is illustrated with an example of application in which the crack path is known a priori due to structural symmetry.Postprint (published version