An efficient measure of the concrete block structure inspection is needed with the increasing demand for concrete blocks. Cracks in the surface of RC member's can be used as a useful measure of quake-proofness of a construction or material fatigue. Specialists used to observe the cracks and experimentally inspect the structures, while applying destructive forces to the blocks. This paper propos...

We discuss apparent characteristic features of Rayleigh scattering of elastic waves from cracks. Interpreting these features, we propose a procedure that in some experimental situations may be useful to distinguish generally-shaped cracks from volume defects. For elliptically-shaped cracks, we propose additional procedures that in principle allow the unique specification of crack size, shape an...

Introduction: The remarkable eruptions from cracks in Enceladus’ South Polar Terrain (SPT) provide a unique window into the interior of an icy satellite. Here we revisit the processes that create cracks and prevent them from freezing in light of the confirmation that Enceladus has a global ocean [1,2] and analyses of the gravity field that indicate that the ice shell is thinnest beneath the SPT...

A crack detection (CD) paint was applied to weld lines of a transverse rib welded joint specimen of a rolled steel for welded structures, and the effects of the paint on visual detection of fatigue cracks were evaluated by performing a fatigue test. Remarkable color development was observed in the CD paint when fatigue cracks propagated along the weld toe lines. At intervals in the fatigue test...

A model is presented for the fragmentation of drying soil, based on the geometry of two-dimensional crack growth. The model restricts itself to the formation of twodimensional cracks. The pertinent parameters used to generate cracking patterns include those used to characterise crack growth development as a random walk, fragmentation of peds above a certain size threshold and attraction of crac...

The new concept of nonlinear output frequency response functions (NOFRFs) is introduced in this paper to detect cracks in beams using frequency domain information. The results show that the NOFRFs are a sensitive indicator of the presence of cracks providing the excitation is of an appropriate intensity. They also constitute an indicative and promising basis, which must further be explored, so ...

We report a case with lacquer cracks observed in the peripheral fundus. A 37-year-old patient with bilateral high myopia who visited our clinic was examined by fluorescein angiography (FA) and fundus autofluorescence (FAF) to determine whether there were myopic fundus lesions. FA showed many arch-shaped, hyperfluorescent linear lesions running circumferentially in the peripheral fundus. FAF sho...

The work that I'm going to describe was funded by the Air Force Materials Lab from February 1972 to February 1974. It is described in an AFML report, TR74-80, available from the Air Force. This report describes a more practical type of problem than has been discussed so far. Our work was directed towards building an ultrasonic system to be used on aircraft in the field to detect cracks around f...

A selection of surface crack problems is presented to provide insights into Stage I and early Stage II fatigue crack growth. Edge cracks at 45o and 90o to the surface are considered for cracks growing in single crystals. Both single crystal slip and conventional plasticity are employed as constitutive models. Edge cracks at 45o to the surface are considered that either (i) kink in the direction...

The corrosion fatigue crack growth characteristics of small (>35pm) surface and corner cracks in aluminum alloy 7075 is established. The early stage of crack growth is studied by performing in situ long focal length microscope (500X) crack length measurements in laboratory air and 1% NaCl environments. To quantify the “small crack effect” in the corrosive environment, the corrosion fatigue crac...