H.-M. Huang
,
J. Pan and S. C. Tang 1) Mechanical Engineering and Applied Mechanics
,
The University of Michigan Ann Arbor
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MI 48109
,
USA 2) Ford Research Laboratory
,
Ford Motor Company Dearborn
,
MI 48121
,
USA
金属学报(英文版)
An approximate macroscopic yield criterion for anisotropic porous sheet metals is adopted in a failure prediction methodology that can be used to investigate the failure of sheet metals under forming operations. This failure prediction methodology is developed based on the Marciniak-Kuczynski approach by assuming a slightly higher void volume fraction inside randomly oriented imperfecte analysis. Here, a nonproportional deformation history including relative rotation of principal stretch directions is identified in a selected critical element of an aluminum sheet from a FEM fender forming simulation. Based on the failure prediction methodology, the failure of the critical sheet element is investigated under the non-proportional deformation history. The results show that thiven non-proportional deformation history.
关键词:
sheet metal forming
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null
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null
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null
D.R.Huang
,
T.F.Ying
,
L.T.Kuo
,
S.J.Wang
,
H.C.Huang
,
C. Y.Huang
材料科学技术（英文）
A single phase brushless spindle motor with innovative design has been developed for application in a DVD drive. The methods used to reduce the cogging torque and to improve the dynamic performance of this new design motor are proposed in this paper. The single phase brushless spindle motor is usually applied for cooling fan, pump and blower before the performance is improved by the reengineering process. The stator configuration and the drive circuit have been remodeled in order to meet the requirements of the spindle motor used in the DVD applications.
关键词:
Atsuhito Honda
,
Masaki Kawano
,
Masyoshi Ishida
,
Kejji Sato
,
Michiro Komatsubara
,
Isamu Ohyama
材料科学技术（英文）
The performance of a 3-phase 6-pole 400 W inverter-drive induction motor was investigated using a variety of non-oriented electrical steels for stator core at PWM inverter fundamental wave frequencies of 30 to 300 Hz. There existed an optimum Si content of the material depending on the tooth flux density. Both reduction of material thickness and stress-relief annealing of the stator core improved the motor efficiency. The influence of Si content on the efficiency was small at lower PWM frequencies, while at higher frequencies the motor efficiency increased with increasing Si content. The Cu loss W-c increased and the Fe loss W-i counteractively decreased with increasing Si content at lower frequencies, while at higher frequencies W-i had dominant effect on the efficiency. Newly developed materials RMA, having lower Fe tosses after stress-relief annealing and higher flux densities with lower Si contents, showed motor efficiencies superior to conventional JIS grade materials with comparable Fe losses.
关键词:
XIAN Aiping LI Peiji CHEN Wenxiu WANG Yikang Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
ChinaCHEN Renvi MEI Dongsheng Panzhihua Institute of Iron and Steel Research
,
Ministry of Metallurgical Industry
,
Panzhihua
,
China associate professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The determination of dffusible hydrogen in U71Mn heavy rail steel,and hydrogen diffusivity as well as the hydrogen distribution in the cross section of blooms with stack cooling were stu- died.The results showed that,most of the hydrogen in blooms of heavv rail steel is diffusible, the hydrogen diffusivity in U71Mn rail steel blooms at room temperature is(0.85—1.02)× 10~(-6)cm~2/s,after stack cooling,the hydrogen content in bloom will decrease greatly which is helpful to form the flake-free phenomenon in the heavy rail produced by Panzhihua Iron and Steel Company.
关键词:
rail steel
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null
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null
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null
XIAN Aiping LI Peiji CHEN Wenxiu WANG Yikang Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
ChinaCHEN Renyi MEI Dongsheng Panzhihua Institute of Iron and Steel Research
,
Panzhihua
,
China associate professor.Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
At panzhihua Iron and Steel Company,hydrogen content in molten heavy rail steel is rather low during smelting in the oxygen top-blown converter,and sloightly increases in tapping and pouring.Average H content varies from 2.0(dry season)to 2.4 ppm(rainy season)at smelt- ing end;2.8 ppm in ladle;and 2.1 ppm(dry season)to 2.3 ppm(rainy season)in mould, which is on a level with RH vacuum circle.The low hydrogen content in molten steel,which is due to both the very dry climate in Panzhiihua region and the LD smelting process,is the main reason why there is little flake in the heavy rail produced by Panzhihua Iron and Steel Com- pany.
关键词:
smelting
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null
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null
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null
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null
