Studies on the growth of small cracks have led to the observation that fatigue life of many engineering materials is primarily “crack growth” from micro-structural features, such as inclusion particles, voids, slip-bands or from manufacturing defects. This paper reviews the capabilities of a plasticity-induced crack-closure model to predict fatigue lives of metallic materials using “small-crack...

Studies on the growth of small cracks have led to the observation that fatigue life of many engineering materials is primarily “crack growth” from micro-structural features, such as inclusion particles, voids, slip-bands or from manufacturing defects. This paper reviews the capabilities of a plasticity-induced crack-closure model to predict fatigue lives of metallic materials using “small-crack...

There is abundant literature regarding virtual reality as a technology of interest in the present age. However, there are few comprehensive studies on strategies that can improve the level of urban design research using this technique. To investigate the issue, this paper first reviews the concept of virtual reality. Next, the opinions of experts in the field of virtual reality technology are s...

The paper reviews the potential of the ultrasonic small incidence method of testing, which enables us to characterize smaller tight cracks quantitatively under load-free conditions. Recently, an important characteristic of the method of being capable of evaluating the cracks from both the accessible and inaccessible sides of material structures with almost similar level of sensitivity, has been...

An assessment of the effects of microstructure on room temperature fatigue threshold and crack propagation behaviour has been carried out on microstructural variants of U720Li, i.e. as-received U720Li, U720Li-LG (large grain variant) and U720Li-LP (large intragranular coherent γ′ variant). Fatigue tests were carried out at room temperature using a 20Hz sinusoidal cycling waveform at an Rratio=0...

In this study, the damage fields near the crack tip in edge-cracked sheet specimens subjected to a constant strain rate of 0.05 min were investigated using real-time radiographic techniques. During the tests, Lockheed-Martin Advanced Technology Center’s high-energy real-time x-ray system (HERTIS) was used to monitor damage initiation and evolution processes near the crack tip. The experimental ...

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...

On the rotor comprehensive fault simulation testbed, characteristics of acoustic emission signal of different crack rotors in various depth and conditions are analyzed by the acoustic emission extraction experiment. The noiseeliminating method of the acoustic emission signal was researched by the wavelet packet technique, the characteristics of acoustic emission signal of the rotor crack was al...

An electromagnetic NDE technique for measuring the crack ooening displacement of surface fatigue cracks is described. A ferromagnetic resonance probe utilizing yttrium-iron-garnet was used to induce eddy currents in an aluminum plate. The crack opening disolacement of a semi-elliptical fatigue crack evaluated at the surface was measured optically at several values of bending stress on the speci...