Occurrence of top down and bottom up fatigue cracking in asphaltic pavements is common. Conventional pavement analysis methods ignore the existence of cracks in asphaltic layers. However, it seems that the responses of cracked pavement would not be the same as a pavement without crack. This paper describes effects of crack type, position and length, and vehicles tire inflation pressure and axle...

There are few experimental results to date describing the crack-propagation threshold behavior of short fatigue cracks under multiaxial loading conditions. To address this need, in the present study, the variation in mixed-mode, high-cycle fatigue-crack growth thresholds with crack size and shape are reported for a Ti-6Al-4V turbine blade alloy, heat treated to two widely different microstructu...

A new approach to microwave eddy current testing for surface cracks in metals involves the use of ferromagnetic resonance in a small garnet crystal placed close to the surface to be tested. It is well known in this case that the induced eddy currents on the metal surface cause a strong displacement of the ferromagnetic resonance frequency. The presence of a crack on the surface produces, by dis...

There are few experimental results to date describing the crack-propagation threshold behavior of short fatigue cracks under multiaxial loading conditions. To address this need, in the present study, the variation in mixed-mode, high-cycle fatigue-crack growth thresholds with crack size and shape are reported for a Ti-6Al-4V turbine blade alloy, heat treated to two widely different microstructu...

Considerable progress has been achieved in fractal characterization of the properties of crack surfaces in quasibrittle materials such as concrete, rock, ice, ceramics and composites. Recently, fractality of cracks or microcracks was proposed as the explanation of the observed size effect on the nominal strength of structures. This explanation, though, has rested merely on intuitive analogy and...

an epoxy resin was modified by silica nanoparticles and cured with an anhydride. the particles with different batches of 12, 20, and 40 nm sizes were each distributed into the epoxy resin ultrasonically. electron microscopy images showed that the silica particles were well dispersed throughout the resin. tensile test results showed that young’s modulus and tensile strength increased with the vo...

A laboratory investigation on a scaled model of a landACT: l ti n a scaled o l f ­ fill liner was conducted to provide data regarding the occurrence l i e e and extent of desiccation cracking of prototype liners. The crack t t of desi t e li rs. intensity factor, CIF, was introduced as a descriptor of the extent of t f , , as i tr as f the extent of surficial cracking. CIF is defmed as the rati...

In 2004, a team comprised of researchers and service providers launched the Safer Crack Use, Outreach, Research and Education (SCORE) project in the Downtown Eastside of Vancouver, British Columbia, Canada. The project was aimed at developing a better understanding of the harms associated with crack cocaine smoking and determining the feasibility of introducing specific harm reduction strategie...