Boundary Element Numerical Simulation Of Crack-Growth Trajectory On Engineering

The study is the sub-project of Project Boundary Element Numerical Simulation of Crack-growth in Engineering Structures (Project No. 8982006) supported by Beijing Physical Science Fund. A new method of numerical simulation of three-dimensional planar crack-growth trajectory is proposed in this thesis. The Boundary Element Method (BEM) is applied to compute Crack Open Displacement (COD). Because of unit area being resolved or linear integrated, the efficiency and precision of boundary element analysis are improved greatly. A Global Crack-line Displacement Fitting Procedure (GCDFP) for computing Stress Intensity Factors (SIF) has been developed. The precision of SIF is compatible with 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, a software has been developed which can automatically trace the crack-growth and obtain reasonable continuous crack-growth trajectory. The results of numerical simulation of crack-growth of ellipse and rectangle utilizing the software computation indicate that crack-line tends to grow into a circle which is consistent with theoretic predict.