In this paper, we’ll answer several abstract, formal questions about the nature of crack growth and nucleation. Bringing a field theory point of view to fracture illuminates things in what I hope will be an entertaining way. Formally, what is the crack nucleation rate? Fracture is an instability of elastic theory under tension. For thermally nucleated cracks, there is an analogy with supercoole...

Although fatigue damage in bone induced by cyclic loading has been recognized as a problem of clinical significance, few fracture mechanics based studies have investigated how incipient cracks grow by fatigue in this material. In the present study, in vitro cyclic fatigue experiments were performed in order to quantify fatigue-crack growth behavior in human cortical bone. Crack-growth rates spa...

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 ...

It is important to have patients describe the injury; acting out the traumatic event if possible. The physician must consider the age of the patient when evaluating the mechanism of injury. For example, the injury resulting from a fall on to the outstretched hand with the wrist extended will vary depending on the patient’s age, typically causing a greenstick fracture in a toddler, a growth plat...

Delamination is an important concern in the context of structural behaviour of laminated composite materials. It is known that delamination can diminish the stiffness and the strength of the material and promote structural failure. Delamination onset and growth is governed by interlaminar fracture toughness of the material. Delamination propagation is frequently dominated by mode II fracture; c...

It is important to have patients describe the injury; acting out the traumatic event if possible. The physician must consider the age of the patient when evaluating the mechanism of injury. For example, the injury resulting from a fall on to the outstretched hand with the wrist extended will vary depending on the patient’s age, typically causing a greenstick fracture in a toddler, a growth plat...

It is important to have patients describe the injury; acting out the traumatic event if possible. The physician must consider the age of the patient when evaluating the mechanism of injury. For example, the injury resulting from a fall on to the outstretched hand with the wrist extended will vary depending on the patient’s age, typically causing a greenstick fracture in a toddler, a growth plat...

The aging-related deterioration of the fracture properties of bone, coupled with higher life expectancy, is responsible for increasing incidence of bone fracture in the elderly; consequently, an understanding of how these fracture properties degrade with age is essential. In this study, ex vivo fracture experiments have been performed to quantitatively assess the effect of age on human cortical...

The fatigue process is viewed as the result of the competing processes of crack growth and crack healing. The crack growth or damage proctss is ont of micrOCnlck development and growth and ultimately coalescence of microcraclc.s and propagation in the form of macrocracks. During the entire process, and especially during the period of microcrack growth, microdamage healing strongly influences th...