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...

This paper presents the effect of centrifugal load in functionally graded (FG) hollow sphere subjected to uniform magnetic field. Analytical solution for stresses and perturbation of the magnetic field vector are determined using the direct method and the power series method. The material stiffness, the magnetic permeability and the density vary continuously across the thickness direction accor...

Crack tip shielding phenomena, whereby the "effective crack-driving force" actually experienced at the crack tip is locally reduced, are examined with reference to fatigue crack propagation behavior in metals, composites and ceramics. Sources of shielding are briefly described in terms of mechanisms relying on the production of elastically constrained zones which envelop the crack (zone shieldi...

There have been few studies to date describing fatigue-crack propagation thresholds under mixed-mode loading conditions in the presence of cracks, that are small as compared to the characteristic microstructural dimensions. To address this need, the variation in mixed-mode, high-cycle fatigue-crack growth thresholds with crack size is reported for a Ti-6Al-4V turbine blade alloy with a fine-gra...

The detection, location, and sizing of a fatigue crack emanating from a fastener hole in an aluminum plate is investigated. Two linear arrays of surface mounted piezoelectric disk transducers send and receive ultrasonic guided waves that are transmitted, reflected, and scattered by both the joint geometry and the fatigue crack. A tomography algorithm is used to detect and locate the crack. Ampl...

Off-road cars’ windshields are vulnerable to different types of stones, road debris and pebbles due to common off paved and gravel surfaces in which they drive. Any attempt to design windshield that minimizes injury and death of occupants during a vehicle accident requires a thorough understanding of the mechanical behavior of automotive windshield subjected to foreign object impact loads...

(FBRs). The factors influencing fatigue lifetime in sodium compared with that in air were investigated by observation of surface cracks in 316FR steel. Furthermore, the effects of sodium environment on fatigue were investigated based on examining the results of thermal striping tests, etc., obtained up to now. The results of the fatigue tests show that many micro cracks in the shearing directio...

An evolutionary approach for fatigue crack detection in cantilever type of machine structure is investigated in this paper. Fault like fatigue crack detection has received a great attention in recent years. A surface transverse open edge crack is considered for this study. Actual fatigue crack may behave like a non-linear due to opening and closing under vibration. But due to small level of vib...