A three-dimensional analysis of crack trapping and bridging by tough particles

摘要: The toughness of a brittle material may be substantially improved by adding small quantities tough particles to the solid. Three mechanisms responsible. Firstly, front crack propagating through solid can trapped particles, causing it bow out between them. Secondly, remain intact in wake crack, thereby pinning its faces and reducing tip stress intensity factors. Finally, enhanced frictional energy dissipation as are pulled crack. This paper estimates improvement that might expected due these mechanisms, means three-dimensional model. analysis considers semi-infinite matrix material, which contains regular distribution particles. Particles modelled finding an appropriate point forces pin faces; effect bowing obstacles is included incremental perturbation method based on work byRice [J. Appl. Mech.56, 619 (1985)]. calculation predicts shape propagates solid; resulting R-curve behaviour; length bridged zone