Fatigue crack growth is a random process and various uncertainties affect the remaining useful life of engineering materials and structures. A general probabilistic life prediction methodology for accurate and efficient fatigue prognosis is proposed in this paper. The proposed methodology is based-on an inverse first-order reliability method (FORM) to evaluate the fatigue life at an arbitrary r...

Acoustic emission (AE) supplies information on the fracture behavior of different materials. In this study, AE activity was recorded in metal coupons with a V-shape notch, which were loaded in fatigue until final failure. AE parameters exhibit a sharp increase approximately 1000 cycles before final failure. The use of AE parameters is discussed both in terms of characterization of the damage me...

INTRODUCTION Stress fractures are common in athletes, military recruits, and Thoroughbred racehorses, and may occur as hip fractures in the elderly. All of these injuries, to some extent, depend upon the propagation of fatigue cracks. Therefore, it is important to characterize the rates at which fatigue cracks grow and how microstructural differences found in cortical bone influence the crack g...

16 This paper presents a novel large-area strain sensing technology for monitoring fatigue cracks in 17 steel bridges. The technology is based on a soft elastomeric capacitor (SEC), which serves as a 18 flexible and large-area strain gauge. Previous experiments have verified the SEC’s capability to 19 monitor low-cycle fatigue cracks experiencing large plastic deformation and large crack openin...

structural health monitoring of cracked structures is one of beloved subject of researchers recently. consider of crack behavior in the water and energy pipeline is important because of environmental problems. in this paper consider of crack parameters in the underwater pipe subjected to mechanical transient load is investigated. for this purpose, three- dimensional parametric model of cracked ...

The fatigue crack growth behavior of a cracked and patch-repaired AA2024-T3 panel has been monitored by acoustic emission (AE). It was found that the overall crack growth rate was reduced and the crack propagation into the adjacent rivet hole was also retarded by introducing the patch repair. AE signals due to crack growth after the patch repair and those due to disbonding of the aluminum-patch...

This paper presents a methodology for assessing the confidence and the predictive capability of prognosis models, using the application of fatigue crack growth analysis. Structures with complicated geometry and multi-axial variable amplitude loading conditions are considered. Several models – finite element model, crack growth model, retardation model, surrogate model, etc. – are efficiently co...

Uniform drying causes a quasi-two-dimensional cellular crack pattern in a thin layer of paste. In our previous research, we found that such cracks are created in a capillary state, and that the growth speed is determined by the rate of increase in tension in the layer, rather than by the magnitude of the tension itself. In this paper, we present a theoretical investigation of the effects of inc...

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...

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...