Two efficient methods for time-dependent fatigue reliability analysis are proposed in this paper based on a random process representation of material fatigue properties and a nonlinear damage accumulation rule. The first method is developed by matching the first two central moments of the accumulated damage to a well-known probability distribution, thus facilitating direct analytical solution o...

The dielectric nanosize dependence of BaTiO₃ powders was investigated by the slurry method, where two series of BaTiO₃ slurries with 10 vol% and 30 vol% solids loadings were prepared as model samples. Applying the Bruggeman-Hanai equation, the high-frequency limiting permittivity (ε(h)) of the slurries was extracted from the dielectric spectra. The ε(h) of the 10 vol% slurry showed abnormal siz...

Many mechanical and structural systems respond dynamically to random environmental loads, such as wind, wave or earthquake forces. Examples include flexible buildings vibrating due to turbulent wind loading and offshore structures moving as a result of combining wave and wind loading. To assess the reliability of such structures it is important to predict their dynamic response, at the design s...

The purpose of this investigation was to determine the effect of creatine (Cr) loading on the onset of neuromuscular fatigue by monitoring electromyographic fatigue curves from the vastus lateralis muscle using the physical working capacity at the fatigue threshold (PWC(FT)) test. Using a double-blind random design, 15 women athletes [mean age 19.0 +/- 2.0 (SD) yr] from the university crew team...

A reliable prognostics framework is essential to address failure mode mitigation and life cycle cost of aerospace systems. Metallic aircraft components are subject to a variety of inservice loading conditions and prediction of fatigue life remains a critical challenge. A hybrid prognostic model, which can accurately predict the crack growth regime and the residual useful life estimate (RULE) of...

An overview of offshore wind turbine (OWT) foundations is presented, focusing primarily on the monopile foundation. The uncertainty in offshore soil conditions as well as random wind and wave loading is currently treated with a deterministic design procedure, though some standards allow engineers to use a probability-based approach. Laterally loaded monopile foundations are typically designed u...

The finite deformation response of fiber-reinforced hyperelastic solids under three-dimensional loading is studied through finite element simulations. The composites are modeled using representative volume elements with random fiber arrangement and periodic boundary conditions. Different matrices and volume fractions are considered. It is found that the shear stiffness of composites with Neo-Ho...

This paper outlines a methodology for determining the statistics associated with the time evolution of a nonlinear multi-body dynamic system operated under input uncertainty. The focus is on the dynamics of ground vehicle systems in environments characterized by multiple sources of uncertainty: road topography, friction coefficient at the road/tire interface and aerodynamic force loading. Drawi...

Melt-blown fibers (dav ∼1 μm) were produced from blends of poly(butylene terephthalate) (PBT) and a partially fluorinated random multiblock copolyester (PFCE) leading to enhanced hydrophobicity and even superhydrophobicity (static water contact angle = 157 ± 3°) of the associated fiber mats. XPS measurements demonstrated quantitatively that the surface fluorine content increased systematically ...