A hybrid finite element-scaled boundary finite element method for crack propagation modelling

• Published in: Computer methods in applied mechanics and engineering Vol. 199; no. 17; pp. 1178 - 1192
• Main Authors: Ooi, E.T., Yang, Z.J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01-03-2010; Elsevier
• Subjects: Applied sciences; Boundary element method; Building structure; Buildings. Public works; Computational techniques; Concrete structure; Construction (buildings and works); Crack propagation; Discrete crack model; Exact sciences and technology; Finite element method; Finite-element and galerkin methods; Fracture mechanics; Fracture mechanics (crack, fatigue, damage...); Fundamental areas of phenomenology (including applications); Mathematical analysis; Mathematical methods in physics; Mathematical models; Modelling; Multiple cohesive crack propagation; Nonlinearity; Physics; Remeshing; Scaled boundary finite element method; Solid mechanics; Structural and continuum mechanics; Finite element method; Multiple cohesive crack propagation; Scaled boundary finite element method; Discrete crack model; Remeshing; Fracture mechanics; Crack array; Ruptures; Notches; Cohesive end; Brittle material; Experimental study; Crack propagation; Stress intensity factors; Stationary crack; Concrete construction; Hybrid finite element; Crack tip; Modelling; Non linear effect; scaled boundary finite element method; Mesh generation
• ISSN: 0045-7825; 1879-2138
• DOI: 10.1016/j.cma.2009.12.005

This study develops a novel hybrid method that combines the finite element method (FEM) and the scaled boundary finite element method (SBFEM) for crack propagation modelling in brittle and quasi-brittle materials. A very simple yet flexible local remeshing procedure, solely based on the FE mesh, is used to accommodate crack propagation. The crack-tip FE mesh is then replaced by a SBFEM rosette. This enables direct extraction of accurate stress intensity factors (SIFs) from the semi-analytical displacement or stress solutions of the SBFEM, which are then used to evaluate the crack propagation criterion. The fracture process zones are modelled using nonlinear cohesive interface elements that are automatically inserted into the FE mesh as the cracks propagate. Both the FEM’s flexibility in remeshing multiple cracks and the SBFEM’s high accuracy in calculating SIFs are exploited. The efficiency of the hybrid method in calculating SIFs is first demonstrated in two problems with stationary cracks. Nonlinear cohesive crack propagation in three notched concrete beams is then modelled. The results compare well with experimental and numerical results available in the literature.