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extrusion and a backward extrusion. When the friction factor of the female die is 0.4, it is advantageous to the forward extrusion forming of the electrode work nose part, while the friction factor...; finite element analysis; friction factor  ......
; 文章编号:1672-7207(2018)04-0857-08 Improved grey wolf optimization algorithm with logarithm function describing convergence factor and its application WU Tiebin1, 2, GUI Weihua1, YANG Chunhua1...-dimensional optimization problem based on the convergence factor about logarithmic function. An initial population was generated based on good point set method to assure that the individuals were distributed......
separately, and an open assessment factor system was established based on related norms, expert method and tunnel construction technology. The assessment flow chart is as follows. Experts weight was first qualified considering factors such as academic background, professional title and working time. Index layer risk was then determined by expert method, and its factor weight was calculated by entropy......
Engineering, Tongji University, Shanghai 200092, China) Abstract: Based on the calculation method for safety factor using stress path, the evolutions of stress path and safety factor for diversion tunnel... of the third principle stress rotates to radial direction. The safety factor decreases gradually to a stable value which is larger than 1 when the excavating face passes the monitoring plane......
(School of Materials Science and Engineering, Anhui University of Technology, Ma’anshan 243002, China) Abstract: The microstructure, texture characteristics and Schmid factor of recrystallized grains... the weakening of texture. The intensity of texture usually increases with increasing the temperature or decreasing the strain rate. The deformation temperature tends to have a stronger effect on the Schmid factor......
criterion. Compared with dilatancy of materials, the non-linear failure criterion exerts greater impact on the stability of shallow tunnels. The safety factor of shallow tunnels decreases and the failure... in the small safety factor. Therefore, the dilatancy as well as non-linear failure criterion should be taken into account in the design of shallow tunnel supporting structure. The supporting structure must......
, friction factor and mass transfer behavior, two models for turbulent flow in circular tubes based on classical Prandtl mixing length theory and a modified mixing length were established. The results... mixing length is much better than the result from the model based on the classical Prandtl mixing length theory. And the friction factor calculated from the model based on the modified mixing length......
; Yingcheng Formation; high-quality volcanic reservoir; controlling factor Cite this article as: DU Shang, SHAN Xuan-long, YI Jian, LI Ji-yan. Controlling factors of high-quality volcanic reservoirs... for the control of the volcanic edifices, facies, and cooling units on the high-quality reservoirs is the combination of lithology and facies [17–19]. The fundamental factor is the degree of pore......
the basic equation of fracture mechanics, the relationship between the fatigue crack growth rate (da/dN) and the maximum stress intensity factor (Kmax) was derived. From this relation, both the values of the threshold intensity factor (Kth) and the fatigue fracture toughness (Kfc) of the material were determined. The fatigue lifetime of the WC-Co cemented carbide was estimated by analysis based......
, which can be solved by the Chebyshev polynomial expansions. The stress intensity factor history with its statistics is analytically derived. Numerical calculations are provided to show the effects... deviation of normalized stress intensity factor history. Key words: functionally graded materials; crack; dynamic response; stochastic; stress intensity factor 1 Introduction Cracks may be induced......