Search results

Research about Subsynchronous Oscillation caused by High-Voltage-Direct-Current Nan Zhou1,a，Guanrong Wang2,b 1,2North China Electric Power University 2 Beinong Road, Changping, Beijing 102206, P.R.China ahycp.zn@gmail.com bsinceilu@live.cn Keywords: HVDC, Subsynchronous oscillation, Unit interaction factor, Damping controller Abstract.
Research about subsynchronous oscillation problems caused by the DC transmission system involves mechanism, mathematical model and analysis method, control scheme, monitoring protection and a series of problems; we should not only consider the interaction between mechanical shaft system and power grid, but the interaction of AC-DC system, especially the DC control system and the mechanical interaction of the axis; layer upon layer associated interactions of center of the DC transmission system, AC power system, generator shaft mechanical characteristics of electromagnetic properties make it very complex.
However, research suggests that adoption of a more detailed and complex modulation function has little effect on the frequency of subsynchronous oscillation, but only affects the amplitude, so qualitative research can adopt ideal modulation function.
This method is referred to the Unit Interaction Factor (UIF) [7].
References [1] Zheng Xu, AC/DC power system dynamic behavior analysis [M], Beijing, mechanical industry publishing house, 2005 [2] Yixin Ni, Yanchun Wang, Shousun Chen, Baolin Zhang, Multimachine system caused by HVDC subsynchronous oscillation research. 1993, 13 (2): 64-71

These are mainly the biomechanical "motion-preserving" properties of the device.
Material properties.
After selecting the factors and levels, the design matrix can be established containing 33 experiments (Scenarios).
It can be seen that there are interactions between the three factors influencing stress.
The present study is different from the previous works [10,34] by investigating a prosthesis with flexible biomechanical properties.

Presence of MF before or after deformation does not change the mechanical properties of crystals [3, 4].
When discussing the assumed mechanisms of MF effect on plastic properties of magnesium-containing alloy, it is necessary to take into account one more factor related to presence of iron (up to 0.4%) in the aluminum alloy.
The intermetallic particles of that form per se adversely affect the mechanical properties of aluminum alloys by reducing their plasticity and increasing their porosity.
Therefore, the aim of the further part of our work was experimental investigation of the effect of static MF on mechanical properties of aluminum alloy with CAl no less than 99.9%.
Petrzhik, Magnetoplastic Effect: Basic Properties and Physical Mechanisms, Crystallogr.

FEA of Planetary Pipe Rolling Process for Stainless Steel Jung-Kil Lee1,a , Dong-bum Kim2,b, Jin-gun Park2,c, Hyuk-soo Shin2,d, Won-yeong Kim2,e, In-hwan Lee3,f, Hae-Yong Cho3,g 1 1600 Chungjeollo (307 Gajeon-ri) Byeongcheonam-city Chunhgnam Province, South Korea 2 Graduate School of Precision Mechanical Engineering, Chungbuk Univ., Gaesin-dong, Heungdeok-gu, Cheongju-si, Chungbuk, South Korea 3 Department of Mechanical Engineering, Chungbuk Univ., Gaesin-dong, Heungdeok-gu, Cheongju-si, Chungbuk, South Korea a kil@kut.ac.kr, b kdb@cbnu.ac.kr, c gareagum@hotmail.com, d guardon@nate.com, e kimwy87@naver.com, f anxanx@cbnu.ac.kr, g hycho@cbnu.ac.kr Key words: Stainless steel, Rolling, Planetary rolling mill, Finite element analysis Abstract: Planetary Pipe rolling process for AISI 304 stainless steel has been studied by using finite element method.
Each of the process parameters affects forming result.
Rotating velocity and revolution does not affect compactibility[4] and are excluded in analysis conditions.
Internal property data for AISI 304 stainless steel in DEFORM-3D is used as property of billet. 3.
Friction is a main factor which makes planetary rolling possible.

Investigation on microstructure and wear properties of an in-situ synthesized TiC gradient coating Liang Xua,Haixia Zhaob, Li Huic, ShaoHua Ma, Song Zhou, YingYing Zhang, Yan Wang College of Mechanical and Electrical Engineering, Shenyang Aerospace University, Shenyang, China.110136 asysyxu@163.com, bsyhk2011@yahoo.cn, csyhuili@126.com Keywords: Laser cladding; Gradient Coating; Wear properties Abstract.
The most outer coating has an excellent comprehensive properties.
TiC has high hardness, high-bending strength, high-abrasion resistance, excellent thermodynamic properties and other characteristics[1].
As Ti has different thermal expansion coefficient, elastic modulus and other properties from those of TiC.
The comprehensive effect of various factors make G/V value decreases so as to the evolution of solidification microstructure evolutes from the mesh crystal to the branches crystal or even the equiaxed crystal.

However, sometimes these angles are distanced and faced in order to improve their mechanical characteristics about the axis of symmetry.
In the past, their design was made in the same way as the double angles arranged in a T shape, that is, considering the limit states of flexural buckling and buckling by flexural-torsional, but ignoring the properties of the connectors and their effect on the modified slenderness ratio, as well as the fact that in this case the warping constant is not negligible.
This new methodology was based on the criteria proposed by Garza et al. (2005) [2] and [3] and includes a term for the modified slenderness as a function of the properties of the connector.
In principle, the torsional buckling contemplates the torsional property (torsional constant J) of the main profiles, it excludes the contribution of the connector profiles.
It is necessary to consider the contribution of the connector element to the torsional properties of the cross-sectional.

However, the favorable mechanical properties of WC-Co cemented carbides are significantly degraded at elevated temperature.
As we all know, the WC grain shape is an important parameter to control during sintering since it influences the mechanical properties of the tools.
Any theoretical or experimental data should help in understanding the factors influencing the WC morphology during sintering.
Microstructure and mechanical properties of WC Ni–Si based cemented carbides developed by powder metallurgy.
Properties of Ni3Al-bonded Titanium Carbide Ceramics.

Introduction The super-high hardness and excellent wear resistance properties of Polycrystalline Diamond (PCD) have led to the wide application of PCD tools in woodworking, automotive and aerospace industries [[] S.
For example, the effects of eight factors need to be analyzed in our system design.
Seven of the eight factors have 4 levels, while one factor has 2 levels.
Signal is the square of the mean value of the results; whereas noise is a measure of the variability of the response, it is caused by uncontrollable factors (noise factors).
L32 suits an experiment of 1 factor with 2 two levels, and 7 factors with 4 levels.

The minimum XRD peak width ratio, b/B, is the calibrated RCF damage parameter that links materials to mechanical engineering (Weibull) failure analysis.
As evident from Fig. 3a, the bearing is affected by severe high-frequency electric current passage which can occur in operation depending on the alternator design.
The tribological properties are still sufficient but continuous chemical decomposition of the lubricant and surface remelting promote hydrogen penetration.
The amount of hydrogen absorbed by the steel depends on the release from the aging lubricant and the available catalytically active fresh metal surface [9]: both affecting factors are enhanced by HF electric current passage.
As the estimated b/B value of 0.71 does not even exceed the XRD L10 equivalent, premature formation of WEB, especially HAB, shows the acceleration of classical RCF under pure mechanical loading by the absorbed hydrogen.

Because the microstructure and properties are more opportunity for creating new alloys and much better than traditional application with a much higher possibility, [1,2,3].
The stabilization of the simple solid solution phase is very significant in terms of the microstructure and properties which can be obtained in these materials, [1].
The material does not have magnetic properties (is nonmagnetic).
[8] Y.Zhang, Mechanical properties and structures of high entropy alloys and bulk metallic glasses composites, Materials Science Forum 654-656, pp.1058-1061, (2010)
[12] Chen Y, Duval T, Hung U, et al., Microstructure and electrochemical properties of high entropy alloys-a comparison with type-304 stainless steel, Corrosion Science 9, pp.2257-2279, (2005)