Fracture analysis based on cohesive models is usually carried out by finite element method. For rigorous analysis of progressive cracking in concrete, discretization errors in the FE analysis are to be minimised. It leads to better understanding of the fracture…
Fracture analysis based on cohesive models is usually carried out by finite element method. For rigorous analysis of progressive cracking in concrete, discretization errors in the FE analysis are to be minimised. It leads to better understanding of the fracture models and the associated softening laws. To achieve this objective a computational framework for adaptive finite element analysis of concrete fracture based on discrete crack model is proposed. The procedure involves at various stages, fracture analysis, error estimation, and mesh refinement. Node patch based superconvergent error-estimation technique proposed by Zienkiewicz and Zhu was adopted for the elastic-softening problem. Hillerborg's fictitious crack model has been chosen to model· cohesive fracture in the present study. The non-linear problem of crack propagation is solved by incremental-iterative procedure. Mesh refinement is automatically done at stages of crack propagation. The procedure is demonstrated on a plain concrete specimen under Mode I fracture condition. Mesh refinement is necessary at crack tip when no special crack tip elements are used. Results indicate the need for adaptive analysis procedure when local behaviour of crack is of interest.