It is considered to be available in reducing the weight of automobiles that the aluminum alloy is applied to manufacture them. The spot welding of aluminum alloys is difficult because of high welding current and small electrical resistance. It is necessary to clarify the relation between the nugget formation and the welding conditions. In this study, the relation between the spot welding condit...

Road and railway tunnels in cold regions are often affected by problems related to water leakage and freezing temperatures. Water leakage in a tunnel leads to ice growth when the temperature goes below freezing and creates favourable environment for fallouts of shotcrete and rock. This paper presents results and observations from laboratory freezing – thawing experiments on rock blocks covered ...

Exploiting pattern formation - such as that observed in nature - in the context of micro/nanotechnology could have great benefits if coupled with the traditional top-down lithographic approach. Here, we demonstrate an original and simple method to produce unique, localized and controllable self-organised patterns on elastomeric films. A thin, brittle silica-like crust is formed on the surface o...

The novel low-cost biologically derived substrates made of biogenic materials such as high-density fiberboards, felt and paper based compositions are investigated by using microscopy techniques. Plates from these materials were carbonized or graphitized, pressed and diced. In order to seal the surface of the substrates they were processed through different post treatments such as siliconization...

The stress intensity factor solution for embedded circular cracks, semicircular and part-circular surface cracks in plates, quartercircular corner cracks in rods, and semicircular surface cracks at a hole in a plate are evaluated using a finite element alternating method. This method of superposition employs the standard 20-noded solid element solution for the untracked solid, and the complete ...

Four wild and two cultivated soybeans were examined for the water imbibition and relationships with seed coat structure, histochemical and epicatechin content using light, fluorescence, electron microscope, and HPLC technique. Cultivated cultivars, Pungsan and Chungja showed the highest water permeability, while the wild soybean lines, YWS16 and YWS136 showed moderate, and YWS1420 and YWS1459 d...

offshore pipelines are an effective tool for transportation of oil and gas which are usually assembled by the use of girth welds. since flaws may naturally exist at such welds, fracture assessment of girth welded offshore pipelines is substantial. current fracture assessment procedures like bs 7910 consider identical material properties for the weld and the base metals. however the strength dif...

The nucleation of internal cavities and their transition to cracks are examined at high spatial and temporal resolutionswithin polydimethylsiloxane (PDMS) elastomers of various cross-link densities under externally applied quasi-static mechanical loads. The focus here is on experiments where the initiation and propagation of internal damage are designed to occur in between two spherical glass b...

We present a motion-based method to extract the multiple 3D crack surfaces from a sequence of 3D X-ray microtomographic mortar images. We verify the correctness and accuracy of results by ground truth obtained with simulated cracks in real specimens. We provide several three-dimensional measures of crack surface, including the number of cracks, surface area, volume, tortuosity, and permeability.