Article history: Received 5 July 2012 Received in revised form 25 September 2012 Accepted 29 September 2012 The fatigue crack growth of the nickel-based superalloy Haynes 230 was investigated at room temperature and 900 °C using digital image correlation (DIC). As expected, the crack growth rates at high temperature were much faster than at room temperature. However, the crack closure levels, w...

Ni-Ti shape memory alloy fiber embedded resin matrix composites were produced for evaluation of "smart denture", a newly developing denture with the function to close its own crack. Their bending strength and shape recovery after instant crack repair was estimated. The embedded fibers did not decrease the bending strength of the composite after repair. The crack closure of the composites was pe...

In components, crack propagation is subjected to crack-closure-mechanisms which affect the build-up of relevant threshold stress intensity factor range during cyclic loading. As structural parts are exposed service loads incorporating a variety load ratios, significant change long-crack value occurs, leading severe ratio dependency crack-closure-mechanisms. Thus, an extensive number experiments...

Lithium-ion batteries have become a widely-used commodity for satisfying the world’s mobile power needs. However, the mechanical degradation of lithium-ion batteries initiated by micro cracks is considered to be a bottleneck for advancing the current technology. This study utilizes a finite element method-based virtual crack closure technique to obtain particleand crack-sizedependent estimates ...

Usually ultrasonic techniques tend to evaluate the closed cracks as smaller than the actual size. In this paper, we describe two strategic techniques for accurately evaluating the closed cracks by means of ultrasound. First, we show the advanced technique utilizing the thermal stress induced by cooling a cracked part. It is shown that a small amount of temperature decrease is effective to open ...

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...