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B. Xu¹, W.P. Tong¹, H. Zhang¹, L. Zuo¹, J. C. He¹
Structural Longevity, Vol.8, No.3, pp. 139-148, 2012, DOI:10.3970/sl.2012.008.139
Abstract A novel technique has been developed to produce nanostructuregrained (NG) Al coatings on Cu plate by means of surface mechanical attrition treatment (SMAT). The reaction diffusion behavior in nanostructure-grained (NG) Al/course-grained (CG) Cu diffusion couple was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The experimental results showed that the aluminizing kinetics of NG coating on Cu plate was obviously enhanced, and the temperature to form compound layer was also greatly reduced with respect to the coarse-grained (CG) Al/coarse-grained (CG) Cu diffusion couple. The activation energy for compound layer growth in the NG-Al/CG-Cu diffusion couple was calculated… More >

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C. Comi¹, R. Pignatelli¹
Structural Longevity, Vol.8, No.3, pp. 149-157, 2012, DOI:10.3970/sl.2012.008.149
Abstract This work focuses on a multi-phase chemo-elastic damage model for the description of the mechanical degradation of concrete induced by the Alkali Silica Reaction (ASR). A threephase and a two-phase simplified versions are considered. The model accounts for ASR kinetics, depending on temperature and humidity conditions, and the swelling pressure exerted by the ASR reaction products on the skeleton. Damage and viscous phenomena are taken into account. The model is used to simulate the experimental tests on concrete reactive beams performed at varying environmental humidity conditions. More >

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Chung-Shin Chang¹
Structural Longevity, Vol.8, No.3, pp. 159-171, 2012, DOI:10.3970/sl.2012.008.159
Abstract The main purpose of this paper is to study the carbide tip’s surface temperature and the cutting forces of milling stainless steel with chamfered main cutting sharp worn tools. The carbide tip’s mounting in the tool holder are ground to a wear depth that is measured by a toolmaker microscope and a new cutting temperature model incorporating tool wear factor and using the variations of shear and friction plane areas occurring in tool worn situations are presented in this paper. The tool tip and cutting edges are treated as a series of elementary cutting tips. The forces and frictional heat… More >

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Suling Wang¹, Yang Li¹, He Liu², Minzheng Jiang¹
Structural Longevity, Vol.8, No.3, pp. 173-191, 2012, DOI:10.3970/sl.2012.008.173
Abstract Hydraulic fracturing is a widely used technology in stimulation of unconventional reservoirs to obtain commercial production. Meanwhile, the bedding plane between sandstone and mudstone is a key challenge in unconventional reservoirs especially. During hydraulic fracture propagation, any diversion or abrupt change in hydraulic fracture path caused by bedding plane, leads to job failure.
In this paper, presents a numerical simulation method for a growth of hydraulic fracture interacting with a geological discontinuity in bedding plane. A 3-D hydraulic fracture model has been developed that can consider the elastic-plastic rock deformation coupled to fluid flow. The fracture growth is modeled by… More >

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Peng Cao¹, Decheng Feng², Changjun Zhou³
Structural Longevity, Vol.8, No.3, pp. 193-206, 2012, DOI:10.3970/sl.2012.008.193
Abstract Based on the classic J2 Plastic Flow Theory, the explicit equation of the equivalent plastic strain was derived elaborately utilizing the tensor analysis method. And a modified method commenced with the plastic flow rule was employed to obtain the same explicit equation. Finally, a subroutine written with FORTRAN was imported into the ABAQUS-version6.11 to validate the robustness of the numerical integrated scheme above The derivation procedure for the explicit equation of the equivalent plastic strain based on J2 Plastic Flow Theory can be utilized as an alternate method to solve complicated constitute integrated problems. And the developed algorithm can save… More >

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