One of the primary objectives in the design of composite structures is the prevention of premature bond failure. Therefore, the characterization of cohesive behavior is an important field of study in structural engineering. Using fracture mechanics principles, the cohesive behavior of an epoxy bonded coarse silica sand aggregate bond interface is studied in this paper, with a focus on finding a...

Endovascular stents made of the superelastic nickel-titanium alloy Nitinol are subjected in service to tens of millions of loading cycles and even "single-event" overloads, both of which can potentially result in fracture and/or complete failure of the device. A fracture-mechanics-based methodology can provide a means to quantify relevant material parameters critical to the design against such ...

Fracture characteristics—such as orientation, type, fluid storage capability, and permeability—are complex yet essential information for understanding fractured reservoirs. Fractures are often perceived as permeable pathways, although many fractures partially or completely inhibit permeability within a reservoir. For example, opening-mode fractures (joints) may be partially or entirely sealed h...

In this study, single-edge cracked uniaxial specimens with an initial crack length of 0.1 in or 0.3 in and wedge-shaped sheet specimens with an initial crack length of 0.3 in were tested at a constant displacement rate of 50 in/min under 1000 psi confining pressure. The specimens were made of a highly filled polymeric material, containing 86% by weight of hard particles embedded in a rubbery ma...

In many cases cracks leading to fracture occur at interfaces between two different constituents, e.g. a fiber and the matrix in a composite. The early solutions of such problems in the context of linear elastic fracture mechanics (LEFM) revealed the presence of an unsatisfactory behavior: rapid oscillations in the stress and displacement fields, implying the physically impossible phenomenon of ...

The deformation behavior and fracture characteristics of NiAl intermetallic alloy containing 5~7 at% Cu are investigated at room temperature under strain rates ranging from 1 ˆ 10 ́3 to 5 ˆ 103 s ́1. It is shown that the copper contents and strain rate both have a significant effect on the mechanical behavior of the NiAl alloy. Specifically, the flow stress increases with an increasing copper con...

Tracer testing has been used to obtain hydraulic properties in a reservoir system and may help characterize the fracture networks inside the reservoir. Numerous studies at various scales have shown that the distribution of many fracture properties (i.e., length, displacement) follows a power law scaling with some cutoffs. Fractal dimension is useful to evaluate the geometric characteristics of ...

Ischemic stroke is a devastating complication of bone fracture. Bone fracture shortly after stroke enhances stroke injury by augmenting inflammation. We hypothesize that bone fracture shortly before ischemic stroke also exacerbates ischemic cerebral injury. Tibia fracture was performed 6 or 24 hours before permanent middle cerebral artery occlusion (pMCAO) on C57BL/6J mice or Ccr2RFP/+Cx3cr1GFP...

Bone properties and response behavior after static or dynamic activation (loading) are still interesting topics in many fields of the science especially in the biomechanical problems such as bone loss of astronauts in space, osteoporosis, bone remodeling after fracture or remodeling after surgery (endoprosthesis and implants) and in osteointegration. This contribution deals with the relation be...

The topic of this thesis is the investigation of the local states of stress resulting from the introduction of a v-notch in a coaxial circle on the pressurized surface of a circumferentially clamped plate subject to axisymmetric loading. The understanding of the fracture behavior of a component experiencing such a condition is of particular interest to the aerospace and defense industries where...