Speaker
Description
Cohesive zone models provide a promising framework for modeling nonlinear fracture processes. Unlike brittle fracture, where the crack energy remains constant, cohesive zone models assume that the energy depends on the crack opening. This dependency gives rise to a traction-separation law, which describes the traction as a function of the crack opening.
In the finite element approximation of fractures, two main approaches can be identified. The first approach treats the crack as a sharp interface, which can be modeled using interface elements or by embedding sharp interfaces within elements (e.g., XFEM). The second approach approximates the crack surface as diffuse or smeared, assigning a finite interface thickness. The phase-field method offers such a diffuse representation by introducing an additional order parameter.
A notable phase-field method for cohesive fracture was proposed by Conti et al. [1] and has since been further developed (e.g., [2,3,4]). This model is supported by proven Gamma-convergence and requires just two field variables: the displacement field and an order parameter. In this talk, the phase-field model for cohesive fracture will be extended to incorporate finite strain. Furthermore, the MCR effect, which limits crack evolution to tensile states, will be included.
S. Conti and M. Focardi and F. Iurlano, “Phase field approximation of cohesive fracture models”, Annales de l’Institut Henri Poincaré C, Analyse non linéaire Vol. 33, pp. 1033–1067, (2016).
F. Freddi and F. Iurlano, “Numerical insight of a variational smeared approach to cohesive fracture”, Journal of the Mechanics and Physics of Solids, Vol. 98, pp. 156–171, (2017).
H. Lammen and S. Conti and J. Mosler, “A finite deformation phase field model suitable for cohesive fracture”, Journal of the Mechanics and Physics of Solids, Vol. 178, 105349, (2023).
H. Lammen and S. Conti and J. Mosler, “Approximating arbitrary traction-separation-laws by means of phase-field theory – mathematical foundation and numerical implementation”, Journal of the Mechanics and Physics of Solids, Accepted for publication, (2025).
