Crack Growth Analysis Using Boundary Elements

The Boundary Element Method (BEM) is now widely regarded as the most accurate numerical tool for the analysis of crack problems in linear elastic fracture mechanics. This "crack growth" software utilizes the BEM and and removes the task of remeshing as the crack propagates, which is one of the drawbacks of finite element software. Furthermore, it evaluates accurate stress intensity factors for which the BEM is renowned. The software uses the established criterion for crack propagation and evaluates residual strength as well as fatigue life calculations. The software features include the use of quadratic continuous and discontinuous elements, evaluation of boundary stresses, displacements and tractions, element or point constraint including skew constraints and mixed-mode path independent integrals for the accurate evaluration of stress intensity factors. The automatic crack propagation algorithm is implemented utilizing an incremental crack extension which employs a special solver to avoid resolution for each crack extendion. The fracture criterion is based on the maximum principal stress and the fatigue crack growth rates are calculated using established formulae.
This software package is based on a formulation of BEM called Dual Boundary Element Method (DBEM). The DBEM retains all of the important features of BEM including: reduced set of equations, simple data preparation, accurate evaluation of stresses, and accurate stress intensity factors evaluation. The standard code is capable fo carrying out stress analysis as well as fracture mechanic scalculations for two-dimensional linear elastic isotropic materials. A special module allowing for modelling stiffeners, is also available with the code. In addition, two other versions of the program for analysis of anisotropic and thermoelastic crack grwoth problems are also available. These versions have the capabilities of th standard linear elastic isotropic code. The software package is accompanied by a user manual for data generation and the analysis program and a book "Dual Boundary Element Analysis of Crack Growth" describing the basic theory of BEM, along with several example problems.