The fracture front in concrete, as well as rock, is blunted by a zone of microcracking, and in ductile metals by a zone of yielding. This blunting causes deviations from the structural size effect known from linear elastic fracture mechanics (LEFM). The size effect is studied first for concrete or rock structures, using dimensional analysis and illustrative examples. Fracture is considered to b...

Rapid development of engineering activities expands through a variety of rock engineering processes such as drilling, blasting, mining and mineral processing. These activities require rock dynamic fracture mechanics method to characterize the rock behavior. Dynamic fracture toughness is an important parameter for the analysis of engineering structures under dynamic loading. Several experimental...

Abstract Nanograin materials have superior properties in mechanics, physics and chemistry. Here, we found a new phenomenon that nanograin formation spontaneously occurs the process of ductile fracture for titanium alloy, dominating mechanism is local severe-plastic-deformation (LSPD). The microstructure evolution during entire monotonic tension was revealed to further understand from plastic de...

Bone is a composite material with five distinct structural levels: collagen molecules, mineralized collagen fibrils, lamellae, osteon and whole bone. However, most fracture testing methods have been limited to the macroscopic scale and there is a need for advanced characterization methods to assess toughness at the osteon level and below. The goal of this investigation is to present a novel fra...

The fracture mechanical behaviour of thin-walled structures with cracks is highly significant for structural strength design, safety and reliability analysis, defect evaluation. In this study, the effects various factors on parameters, crack initiation angles plastic zones cylindrical shells are investigated. First, based J-integral displacement extrapolation methods, stress intensity circumfer...

The fracture mechanics examines the development and expansion of cracks in solids and how they affect the deformation of materials. The stress intensity factors at the tip of the crack and the critical stress intensity factors or fracture toughness of materials are considered in the relevant criteria. There are three main modes of applying forces to a crack including the tensile mode, shear mod...

In linear elastic fracture mechanics the stress and strain magnification at crack tip is characterized by intensity factors which have been obtained for a large variety of loading specimen geometries course mode II test included. this paper not only different kinds boundary conditions contact surfaces will be discussed but plastic one. The rotation center line also discussed. results show power...