Numerical modeling of fracture propagation using continuum damage and cohesive crack models

Resumo

Damage mechanics is a branch of the inelastic theory, which is concerned with the impact of the growth
of microvoids or microcracks in solids. From a structural point of view, a solid body loses stiffness as a
consequence of damage evolution. This work aims at understanding fracture propagation in quasi-brittle materials,
considering continuum damage and cohesive crack models. The cohesive zone model and isotropic damage model
are implemented into the in-house framework GeMA. In the finite element context, modeling of the material
degradation process is a challenging task due to the occurrence of critical points and convergence problems in the
global solution. Therefore, robust continuation methods are required to overcome this obstacle. Regularization
techniques are applied in the isotropic damage models to reduce the pathological sensitivity of the solution to the
finite element size. Numerical simulations illustrate the ability and limitations of the proposed models to simulate
fracture propagation. Additionally, various damage criteria and evolution laws proposed by several authors are
adopted to evaluate the impact of the model on the global behavior. The results indicate that continuum damage
and cohesive zone modeling are crucial tools to provide realistic responses related to fracture processes.