Prof. G. Lubineau, gave a lecture titled “Adaptive coupling between damage mechanics and Peridynamics: A route for objective simulation of material degradation up to complete failure” at AMSS on 30, August 2017.
The objective (mesh-independent) simulation of evolving discontinuities, such as cracks, is still today a challenging task. Indeed, current available techniques are highly complex and very often involve outrageous computational costs, thereby making simulations up to complete failure quite difficult. In order to circumvent this problem, they proposed herein a new hybrid computational framework in which local continuum damage mechanics was adaptively coupled with peridynamics to achieve the objective simulation of all the steps related to material failure, i.e. damage nucleation, crack formation and propagation. Local continuum damage mechanics successfully described the degradation related to distributed microscopic defects before the formation of a macroscopic crack. However, when damage localization occured, spurious mesh dependency arised, making the simulation of crack propagation challenging. On the other hand, the peridynamic theory was very promising for the simulation of fracture, as it naturally allowed to embed discontinuities within the displacement field. Here, they presented a hybrid local-continuum damage/peridynamic model. Local-continuum damage mechanics was used to describe“volume" damage before localization. Once localization was detected at a point, the remaining part of the energy was dissipated through an adaptive peridynamic model capable of the transition to a “surface" degradation, typically a crack. They believed that this framework, which actually mimics the real physical process of crack formation, was the first bridge between continuum damage theories and peridynamics. Two-dimensional numerical examples were used to illustrate that an objective simulation of material failure can be achieved by this method.
G. Lubineau is professor of Mechanical Engineering and Chair of the Mechanical Engineering program at KAUST. He is principal investigator for COHMAS (COmposite and Heterogeneous Materials Analysis and Simulation, an integrated environment for composite engineering that he created in 2009 when joining KAUST). Current research interests include: integrity at short and/or long-term of composite materials and structures, inverse problems for the identification of constitutive parameters, multi-scale coupling technique, multi-functional materials and modeling, nano and multifunctional materials and devices. Before joining KAUST, Pr. Lubineau was a faculty member at the École Normale Supérieure of Cachan, and a non-resident faculty member at the École Polytechnique, France. He also served as a visiting researcher at UC-Berkeley.