Boundary Element Numerical Simulation of Three-Dimensional Crack-Growth Trajectory
Deng Jiangang(1), Jiang heyang(1), Li Zhailiang(2)
(1,Civil Engineering Department, Beijing University of Technology, Beijing 100022)
(2,Research Institute of Solid Mechanics, Beijing Univerisy of Aeronautics & As tronautics, Beijing 100083)

Abstract: A new method of numericl simulation of three-dimensional planar  crack-growth trajectory is proposed in this article. The boundary element method (BEM) is applied to compute crack open displacement (COD). Because of unit area beihg resolved or linear integrated, the efficiency and precision of boundary element analysis are improved significantly. A global crack-line displacement fitting procedure (GCDFP) for computing stress intensity factors (SIF) is developed. The precision of SIF is the same as the corresponding COD data. The crack-growth increment of crack-line is computed by Paris formula followed by fitting using three-time B-spline function. Further more, the software is developed to trace automatically the crack-growth and to obtain reasonable continuous crack-growth trajectory. The results of numerical simulation of crack-growth of ellipse and rectangle by the software computation indicate that crack-line tend to grow into a circle, this is consistent with the theoretic prediction.
Keywords: three-dimensional crack-growth trajectory, numerical simulation, boundary element, stress intensity factor, B-spline function.