ABSTRACT
Abstract The multiscale approach is introduced to model the interaction between the main crack and surrounding smaller cracks. The smaller cracks are divided into: (a) microcracks, which smaller than the main crack process zone, and (b) mesocracks, i.e., cracks with sizes in the range between the size of the main crack and its process zone size. The different crack sizes are asymptotically considered as different scales. The crackmesocrack interaction is modeled by introducing an effective medium. The crackmicrocrack interaction is modeled at the smallest scale level as a process of fracturing microcracked volume elements at the crack front. A volume element size has been found that minimizes the macroscopic fracture toughness. Fracturing of the volume elements thickens the crack. That makes the macroscopic fracture toughness greater than the microscopic one. Keywords: Multiscale Approach, Interaction, Mesocrack, Microcrack, Effective Medium, Fracture Toughness, Averaged Stress Intensity Factor.
