Chapter 8 - Computational Approaches to Quasibrittle Fracture and Its Scaling

Abstract

Computationally, the most efficient model capable of resolving the stress profile along the fracture process zone is the cohesive crack model. One primitive way is solving repeatedly by finite elements the complete response history of the structure for a sequence of increasing sizes and then collecting the maximum load values. The usual way to solve the maximum load of a given structure according to the cohesive crack model was integrating these equations numerically for step-by-step loading. However, recently it was discovered that under the assumption that there is no unloading in the cohesive crack (which is normally the case); the size effect plot can be solved directly, without solving the history of loading before the attainment of the maximum load. The cohesive crack model presented in the chapter illustrates the transition from failure at a relatively large fracture process zone in the case of small structures to the failure at a relatively small process zone in the case of large structures.