Shear sliding along a fault plane leading crack propagation can be classified as a strike-slip fault movement. The cracks propagated from the extensional quadrant or compressional quadrant of fault is named wing crack...
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A team of transparent specimens using a type of casting resin are employed, which has brittle fracture properties of rock-like material under frozen environment. The primary flaws in samples are made of three thin alu...
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A team of transparent specimens using a type of casting resin are employed, which has brittle fracture properties of rock-like material under frozen environment. The primary flaws in samples are made of three thin aluminum films. The propagation and coalescence process of three-dimensional (3D) flaw sets were observed. The experimental results show that wrapping wing cracks individually initiate and grow from every pre-existing flaw end at the beginning of fractures. Then the interaction roles between the flaws gradually become stronger and stronger, and principally, the secondary cracks are induced to extend towards the direction opposite to wing crack. This type of crack is so called wrapping anti-wing crack (against wrapping wing crack). The whole specimens will be broken off by the coalescence fracture of wrapping wing and anti-wing cracks. Furthermore, the distribution type of 3D flaws will greatly affect some parameters of growth and coalescence of 3D cracks. Especially, the initial growth angle of crack will change by about 10. Finally, the primary fractured pattern and mechanism of 3D flaw sets are discussed in this paper.
Stonecutters bridge is a cable-stayed bridge having an unprecedented central span of 1018 m. The buffeting action of gusty wind on the bridge therefore needs careful consideration. In order to obtain a realistic estim...
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Stonecutters bridge is a cable-stayed bridge having an unprecedented central span of 1018 m. The buffeting action of gusty wind on the bridge therefore needs careful consideration. In order to obtain a realistic estimate of the wind turbulence characteristics, Highways Department of HKSAR erected a 50m high meteorological mast at the bridge site and at the same time conducted a terrain model wind tunnel experiment. On the basis of the field measurement and terrain model test results, a set of wind turbulence characteristics was worked out as input parameters for the buffeting analysis. The power spectral density and variance of the nodal displacements of the bridge structure are computed using finite element method and random vibration theory. This paper presents the analysis results.
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