Laura De Lorenzis' KTH Solid Mechanics KEYNOTE seminar "Energy decompositions in variational phase-field modeling of brittle fracture"
Tid: To 2023-10-12 kl 16.15 - 17.45
Medverkande: Professor Laura De Lorenzis, Eidgenössische Technische Hochschule Zürich, Switzerland
Abstract. In the past two decades, computational fracture mechanics has been revolutionized by the advent of the variational phase-field approach. This paradigm, which bears relation to Griffith’s theory in classical fracture mechanics, to gradient damage models in continuum mechanics, as well as to phase-field models for phase transformations in computational material science, has opened the pathway to fracture and fatigue simulations of unprecedented flexibility, which is motivating an enormous interest from the academic and industrial worlds alike. For the simplest case of quasi-static brittle fracture in small deformations under predominant tension, the research field is by now quite mature: the available variational formulations are well understood; several groups worldwide have experimentally validated the approach in a variety of loading and geometry conditions; some open-source implementations are available online, a few of which suitable for use with commercial codes. However, for brittle fracture under multiaxial stress states, and especially in cases involving significant compression, the available formulations based on various energy decompositions are not yet satisfactory. In this talk, based on a recently submitted joint paper with F. Vicentini, C. Zolesi, P. Carrara and C. Maurini, staying within the realm of variational approaches, I will talk about i. the main issues with existing energy decompositions; ii. the requisites that an energy decomposition should satisfy in relation to both crack initiation and crack propagation; iii. a new energy decomposition that solves (at least partially) the issues with the existing ones.