this study investigates propagation of mode i crack in b70 pre-stressed concrete sleepers by fracture mechanics approach. a new experimental analysis is done for notched b70 pre-stressed concrete sleepers with replica test and image analysis. a scanning electron microscope test (sem) and an image analysis are applied for the replica test in order to determine crack length and crack mouth openin...

    The combination of horizontal drilling along with hydraulic fracturing has significantly improved the production of hydrocarbon reservoirs and made it possible to extract the relatively impermeable and uneconomical reservoirs. The production rate of oil and gas wells increases proportional to hydraulic fracture aperture or crack opening displacement (COD). This is an important parameter i...

Previous studies on elastic wave propagation in fractured media have demonstrated that a single planar fracture supports fracture interface waves and that two plane parallel fractures support fracture channel waves. Here, the results are presented for plane wave propagation through an infinite number of plane parallel fractures with equal fracture spacing and fracture stiffnesses. Analysis of t...

Abstract Computational modeling of the initiation and propagation complex fracture is central to discipline engineering mechanics. This review focuses on two promising approaches: phase-field (PF) peridynamic (PD) models applied this class problems. The basic concepts consisting constitutive models, failure criteria, discretization schemes, numerical analysis are briefly summarized for both mod...

This paper presents a novel numerical technique to simulate the crack propagation process for inhomogeneous solids. The criteria of crack growth and path selection are expressed in terms of some simple functions of fracture energy and loading phase angle. The energy release rate and loading phase angle for mixed mode cracks are evaluated by the ®nite element method with a mesh-adaptive techniqu...

We have carried out systematic fracture experiments in a single edge notch geometry over a range of stretch rates on dual crosslink hydrogels made from polyvinyl alcohol chains chemically crosslinked with glutaraldehyde and physically crosslinked with borate ions. If the energy release rate necessary for crack propagation was calculated conventionally, by using the work done to deform the sampl...

The authors have been developing a crack propagation analysis system that can deal with arbitrary shaped cracks in threedimensional solids. The system is consisting of mesh generation software, a large-scale finite element analysis program and a fracture mechanics module. To evaluate the stress intensity factors, a Virtual Crack Closure-Integral Method (VCCM) for the second-order tetrahedral fi...