Although bulk silicon is not known to exhibit susceptibility to cyclic fatigue, micron-scale structures made from silicon films are known to be vulnerable to degradation by fatigue in ambient air environments, a phenomenon that has been recently modeled in terms of a mechanism of sequential oxidation and stress-corrosion cracking of the native oxide layer. To date, most stress-life (S=N ) fatig...

Fatigue cracking is one of the most common failure modes of various load-bearing structures. Even though sensors of many different types have been developed for crack detection, very few can monitor crack growth with a high sensitivity. This paper presents an antenna sensor that is capable of monitoring the growth of fatigue cracks with a sub-millimeter resolution. According to microstrip patch...

Bulk-metallic glasses (BMGs) are now candidate materials for structural applications due to their exceptional strength and toughness. However, their fatigue resistance can be poor and inconsistent, severely limiting their potential as reliable structural materials. As fatigue limits are invariably governed by the local arrest of microscopically small cracks at microstructural features, the lack...

The mechanisms of fatigue-crack propagation in ceramics and intermetallics are examined through a comparison of cyclic crack-growth behavior in ductile and brittle materials. Crack growth is considered to be a mutual competition between intrinsic mechanisms of crack advance ahead of the crack tip, which promote crack growth, and extrinsic mechanisms of crack-tip shielding behind the tip, which ...

The present paper examines crack growth in a range of aerospace and automotive structural adhesive joints under cyclic-fatigue loadings. It is shown that cyclic-fatigue crack growth in such materials can be represented by a form of the Hartman–Schijve crackgrowth equation, which aims to give a unique and linear ‘master’ representation for the fatigue data points that have been experimentally ob...

The fatigue growth of a fiber reinforced composite laminate was characterized under thermal cycling using a combined experimental and computational investigation. Twenty-four ply composite laminates (1⁄20 12=90 12 ) are fabricated with a pre-existing delamination, and subjected to thermal cycling in an environmental chamber. The large mismatch in the coefficients of thermal expansion is used to...

Effect of holding time and temperature on the fatigue life of micro Sn-Ag-Cu solder joint has been studied with waveform of triangle and trapezoid wave at 298K and 398K. Both the microstructural coarsening and the crack propagation occurred simultaneously and therefore the cyclic load decreased rapidly in the trapezoidal wave at 398K compared with the other conditions. Therefore, under the cond...

Steels are heavily used in infrastructure and the transportation industry, and enhancing their fatigue resistance is a major challenge in materials engineering. In this study, by introducing a gradient microstructure into 304 austenitic steel, which is one of the most widely used types of stainless steel, we show that a strength gradient substantially enhances the fatigue life of the material. ...

Abstract: To ensure the rail transportations safety, evaluation of fatigue behavior of the rail steel is necessary. High cycle fatigue behaviour of a rail steel was the subject of investigation in this research using fracture mechanics. Finite element method (FEM) was used for analyzing the distribution of the stresses on the rail, exerted by the external load. FEM analysis showed that the ...

ÐThe high-temperature fatigue-crack propagation and fracture resistance of a model g-TiAl intermetallic composite reinforced with 20 vol.% ductile b-TiNb particles is examined at elevated temperatures of 650 and 8008C and compared with behavior at room temperature. TiNb reinforcements are found to enhance the fracture toughness of g-TiAl, even at high temperatures, from about 12 to 040 MPa m, a...