sudden fracture is one of the major failure modes in brittle materials. plexiglass (polymethyl methacrylate) is a well known brittle polymer, widely used in various industries. many types of notches, particularly v-shaped notches, are sometimes used in the components made of plexiglass. these notches can dramatically decrease the load bearing capacity of components due to the concentration of s...

Natural and artificial materials including rocks and cement-based materials such as concrete and cement mortar are affected both physically and chemically by various natural factors known as weathering factors. The freeze-thaw process, as a weathering factor, considerably affects the properties of rocks and concrete. Therefore, the effect of the freeze-thaw process on the physical and mechanica...

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...

the cracked brazilian disc (cbd) specimen is widely used in order to determine mode-i/ii and mixed-mode fracture toughness of a rock medium. in this study, the stress intensity factor (sif) on the crack-tip in this specimen is calculated for various geometrical crack conditions using the extended-finite element method (x-fem). this method is based upon the finite element method (fem). in this m...

The cracked Brazilian disc (CBD) specimen is widely used in order to determine mode-I/II and mixed-mode fracture toughness of a rock medium. In this study, the stress intensity factor (SIF) on the crack-tip in this specimen is calculated for various geometrical crack conditions using the extended-finite element method (X-FEM). This method is based upon the finite element method (FEM). In this m...

In this paper a new method to determine the fracture properties and strain energy release rate for Carbon- Polyester composite has been introduced.  Fracture characteristics such as critical stress intensity factor and critical strain energy release rate for mode I, mode II and mixed mode loading were determined using Arcan type specimen. 130 layers of carbon fiber polyester woven composite wit...

In inclined U-notches, the mixed mode (I + II) loading occurs and the mode ratio can be increased by varying the notch angle. In this paper, the effect of the inclined U-notch geometry, i.e. the notch depth, the notch angle, the notch root radius, and the position of the notch with respect to supports, on the mode ratio (KII/KI) have been studied. Three-point bending and plane strain condition ...

In this paper, effects of ply orientation of adjacent plies with (ϕ//θ) interfaces on mode II critical strain energy release rate (fracture toughness) of multidirectional (MD) laminate has been studied. Ply orientation of adjacent plies is one of the most important parameters affects the mode II critical strain energy release rate () in the initiation of the delamination. To  study this paramet...