An enriched dual boundary element method formulation for linear elastic crack propagation

Autor(es)

Andrade, H. C. ; Leonel, E. D.

• Tipo de documento: Artigo Científico
• Fonte: Engineering Analysis with Boundary Elements; v. 121, p. 22-pg., 2020-12-01.

Resumo

This study presents an eXtended Boundary Element Method (XBEM) formulation for simulating the linear elastic crack growth in two-dimensional domains. A displacement approximation enrichment based on the Williams first-order expansions is used to represent the near-tip square root behavior predicted by the linear elastic fracture mechanics. This strategy also enables the direct evaluation of the Stress Intensity Factors (SIFs) after a crack tip tying constraint is enforced at the crack tip to accommodate the additional enrichment parameters. Additionally, discontinuous functions are embedded into the displacement approximation of elements intercepted by cracks to avoid remeshing of these elements. For the discontinuous enrichment, new equations are provided by imposing displacement continuity conditions at the crack mouth. Shifted enrichment functions are used to preserve the physical meaning of the nodal parameters and to reduce the singularity order of the integral kernels containing the enrichment terms in the XBEM formulation. Furthermore, an enriched traction approximation is proposed to apply concentrated forces and support points along the boundary. When considering the XBEM formulation, changes in the conventional BEM are minimal, which facilitates the implementation of the extended approach into existing codes. Three numerical examples demonstrate the application of the proposed XBEM formulation in fracture modeling. (AU)

• Processo FAPESP: 16/23649-0 - Formulações numéricas baseadas no Método dos Elementos de Contorno Isogeométrico para a análise probabilística da propagação de fissuras em meios não homogêneos
• Beneficiário: Heider de Castro e Andrade
• Modalidade de apoio: Bolsas no Brasil - Doutorado