Smoothed methods for fracture problems and application to composite materials

Abstract

Fracture is one of the most common failures in structures and components. Numerical methods are usually used for fracture and fatigue analysis of structures. In this thesis, smoothing technique is applied to develop numerical methods for fracture mechanics and the application of smoothed method is extended to composite materials. The smoothing technique is applied to two-dimensional linear elastic fracture problem and plastic fracture mechanics. Also smoothing technique is combined with XFEM and applied to composite materials and extended for three-dimensional fracture problems. Through these methods, some advantages are observed. No singular term appear in integrand. No transitional elements are needed. Smoothing technique can provide more accurate results. At the same time a five-node singular element and seven-node singular element are developed for linear elastic fracture mechanics and plastic fracture mechanics respectively. These elements are proved to be effective.