For composite structure, fracture toughness is a dominant parameter when using cohesive laws to predict the nominal strength. In the present study the compact tension test is performed on composites structures and is simulated using FEM. The process of fracture takes places in two sequential stages, crack initiation and crack propagation. The critical energy release rate is determined using the...

[1] Water-rock interactions within variable aperture fractures can lead to dissolution of fracture surfaces and local alteration of fracture apertures, potentially transforming the transport properties of fractures over time. Because fractures often provide dominant pathways for subsurface flow and transport, developing models that effectively quantify the role of dissolution on changing transp...

The use of computer-assisted procedures before or during surgery provides orthopaedic specialists additional information that help them to reduce surgery time and to improve the understanding of the fracture peculiarities. In this context, the calculation of the fracture area is one of the main tasks in order to better comprehend the fracture. This paper presents the initial results of a method...

The fracture modes of hydroxyapatite (HA) scaffolds fabricated by direct-write assembly (robocasting) are analyzed in this work. Concentrated HA inks with suitable viscoelastic properties were developed to enable the fabrication of prototype structures consisting of a 3-D square mesh of interpenetrating rods. The fracture behavior of these model scaffolds under compressive stresses is determine...

We present results of 3D numerical modeling using a series of simple point scatterers to create synthetic seismic shot records collected over regular, discrete, vertical fracture systems. The background medium is taken to be constant velocity. The model contains a series of point scatterers delineating the top tip and bottom tip of each vertical fracture. We use these results to gain an underst...

An irregular lattice model is proposed for simulating quasistatic fracture in softening materials. Lattice elements are defined on the edges of a Delaunay tessellation of the medium. The dual sVoronoid tessellation is used to scale the elemental stiffness terms in a manner that renders the lattice elastically homogeneous. This property enables the accurate modeling of heterogeneity, as demonstr...

Cap rocks are dams which can prevent the upward movement of hydrocarbons. They have disparities and weaknesses including discontinuities, crushed areas, and faults. Gas injection is an effective mechanism for oil recovery and pore pressure. With increasing pore pressure, normal stress is reduced, and the integrity of impermeable boundaries (cap rock, fault, etc.) becomes instable. A successful ...

Some cases of infant skull fracture fall under the category of forensic study where it is not obvious whether the head trauma happened due to an accident or abuse. To be able to determine the cause of the head trauma with sufficient accuracy, biomechanical analysis using finite element modeling of the infant cranium has been established. By simulating the trauma, one may be able to obtain the f...

[1] In recent years, significant advances have been made in our understanding of the complex flow processes in individual fractures, aided by flow visualization experiments and conceptual modeling efforts. These advances have led to the recognition of several flow regimes in unsaturated individual fractures subjected to different initial and boundary conditions. For an idealized smooth fracture...

Numerical simulation is very useful for understanding the hydraulic fracturing mechanism. In this paper, we simulate the hydraulic fracturing using the distinct element approach, to investigate the effect of some critical parameters on hydraulic fracturing characteristics. The breakdown pressure obtained by the distinct element approach is consistent with the analytical solution. This indicates...