Continuous-discontinuous modeling of failure in micromorphic media

Resumo

Deformation and failure are typically developed at multiple scales for the majority of engineering materials. At the macroscopic level of observation, structural rupture is triggered by a localized failure that corresponds to a loss in the material continuity within a specific region of the body. This localized failure is preceded by microcrack coalescence that can be observed at lower observation levels. This study investigates the propagation of a discrete fracture within a continuum damage process zone within the framework of micromorphic media. The adopted generalized continuum theory is well suited for modeling microstructured materials and also recognized in the relevant literature for its regularization properties due to its non-local formulation. Microcracking prior to coalescence is represented by continuum damage models based on a recently proposed formulation for elastic degradation in micromorphic media. The propagation of a discrete fracture is based on the analysis of a generalized micromorphic acoustic tensor, which is here derived considering the concepts of acceleration waves. When instability is detected, a discontinuity is introduced by the Extended/Generalized Finite Element Method. The required implementations for the numerical investigation of the proposed model are conducted in the open-source software INSANE.