A variational approach to brittle fracture and cohesive delamination:modelling and technological applications

A new computational model is used for the study of fracture phenomena in homogeneous and composite materials.The computational model is based on the coupling betweenthe phase field model and the cohesive zone model withinthe framework of the finite element method. This model isadopted from literature and consistently extended. The enhancements enclose the combination of the model with plasticity and its extension to the 3D finite elasticity framework.This extension is formulated in a consistent way by meansof the variational approach. The model is validated throughnumerical examples mostly based on experimental results.The experiments are designed and performed by means ofexperimental facilities suitable for micro testing. The numerical simulations comprehend problems at different scales ofhomogeneous and composite materials in the bi-dimensionaland three-dimensional space. The model results particularlyappropriate for many technological applications. Among thedifferent applications, the following cases are analysed: thecompetition between crack propagation and plasticity; theadhesive wear phenomenon considering the fracture of themicro asperities of two surfaces in contact; the mechanicalbehaviour of a nanolaminate and a microlaminate; the interaction between crack propagation and delamination. Inthe latter application is where the model shows its strength.The competition between crack propagation and delamination in composite materials is simulated without the necessity of remeshing or crack tracking algorithms. The model isparticularly suitable for the exploitation in many engineeringindustrial fields.