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Online since: July 2013
Authors: Lars P. Mortensen, Dong Hyeon Ryu, Ying Jun Zhao, Kenneth J. Loh
Second, the electrical properties of films subjected to post-fabrication thermal annealing were compared.
Dispersion of nanotubes was required in order to take advantage of the unique electromechanical properties of CNTs [10].
One of the main goals of this study was to investigate the electrical properties of this sprayed MWNT-based thin film.
As a result of this study, it was found that the spray-fabricated MWNT-based films exhibited fairly stable electrical properties.
Hwang, Carbon nanotube composites multi-sensing characteristics based on electrical impedance properties, J.
Dispersion of nanotubes was required in order to take advantage of the unique electromechanical properties of CNTs [10].
One of the main goals of this study was to investigate the electrical properties of this sprayed MWNT-based thin film.
As a result of this study, it was found that the spray-fabricated MWNT-based films exhibited fairly stable electrical properties.
Hwang, Carbon nanotube composites multi-sensing characteristics based on electrical impedance properties, J.
Online since: January 2012
Authors: Dmitri A. Molodov, Günter Gottstein, Tatiana Gorkaya
Introduction
The behavior of grain boundaries with regard to their response to applied forces can be crucial for the mechanical properties of crystalline materials.
As known [1-10], boundary migration caused by an applied mechanical stress can result in a shear strain of the crystal region behind the moving boundary.
(a) Misorientation dependence of measured (points) and calculated (lines) coupling factors for <100> symmetrical tilt grain boundaries and (b) activation enthalpy H of stress induced migration of these boundaries [17].
The obtained coupling factors, however, were found to deviate from the coupling factor calculated according to the tangent rule (Fig. 3).
An increase of the migration activation energy with rising impurity concentration suggests that the migration mechanism is substantially affected by the solute segregation.
As known [1-10], boundary migration caused by an applied mechanical stress can result in a shear strain of the crystal region behind the moving boundary.
(a) Misorientation dependence of measured (points) and calculated (lines) coupling factors for <100> symmetrical tilt grain boundaries and (b) activation enthalpy H of stress induced migration of these boundaries [17].
The obtained coupling factors, however, were found to deviate from the coupling factor calculated according to the tangent rule (Fig. 3).
An increase of the migration activation energy with rising impurity concentration suggests that the migration mechanism is substantially affected by the solute segregation.
Online since: December 2012
Authors: Paulus Wilfred, Meor Sulaiman Meor Yusoff, E.M. Mahdi, Mohd Hamdi Abdul Shukor
The properties that were analyzed were its crystallite sizes, relative crystallinity, phases, and chemical composition.
Generally, the leaching process is dependent on three or more factors, but in this particular study, only molarity, kinetics, and temperature will be considered [5,6].
These impurities will usually embed themselves in the Ti-O matrix in the form of subsitutional impurities, altering properties such as mechanical strength, band gaps and reactivity [4-6].
For comparison purposes, both the nano-TiO2 and the commercial nano-TiO2 were analyzed for properties such as crystallite size and morphology.
The presence of sulfur, although relatively significant, did not adversely affect the overall mechanical properties of the nano-TiO2 [8].
Generally, the leaching process is dependent on three or more factors, but in this particular study, only molarity, kinetics, and temperature will be considered [5,6].
These impurities will usually embed themselves in the Ti-O matrix in the form of subsitutional impurities, altering properties such as mechanical strength, band gaps and reactivity [4-6].
For comparison purposes, both the nano-TiO2 and the commercial nano-TiO2 were analyzed for properties such as crystallite size and morphology.
The presence of sulfur, although relatively significant, did not adversely affect the overall mechanical properties of the nano-TiO2 [8].
Online since: July 2012
Authors: Yu Xin Gao, Bao Ying Yu, Fen Lian Xu
Taking all above factors, specific surface area of 550m2/kg on clinker is chosen in this investigation.
The effect of slag on the mechanical properties of LCC can be concluded into three aspects.
Fig. 4 Particle size distribution of fly ash (FA1 FA2) by laser particle analyzer Fig. 5 Particle size distribution of slag (S1 S2 S3) by laser particle analyzer Conclusions Based on the above results, LCC with lower power consumption, better environmental protection and higher mechanical properties can be successfully developed.
Hibbert, Selected engineering properties of concrete incorporating slag and metakaolin, Construction and Building Materials. 19(2005) 460-472
[10] Huiwen Wan, Zhonghe Shui, and Zongshou Lin, Analysis of geometric characteristics of GGBS particles and their influences on cement properties, Cement and Concrete Research. 34(2004) 133-137
The effect of slag on the mechanical properties of LCC can be concluded into three aspects.
Fig. 4 Particle size distribution of fly ash (FA1 FA2) by laser particle analyzer Fig. 5 Particle size distribution of slag (S1 S2 S3) by laser particle analyzer Conclusions Based on the above results, LCC with lower power consumption, better environmental protection and higher mechanical properties can be successfully developed.
Hibbert, Selected engineering properties of concrete incorporating slag and metakaolin, Construction and Building Materials. 19(2005) 460-472
[10] Huiwen Wan, Zhonghe Shui, and Zongshou Lin, Analysis of geometric characteristics of GGBS particles and their influences on cement properties, Cement and Concrete Research. 34(2004) 133-137
Online since: September 2021
Authors: Murotbek B. Boydadaev, Soyibon S. Negmatov, Zokirkhon T. Munavvarkhanov, Alloberdi M. Madraximov
However, it is in combination with binders that they realize their unique properties, giving solutions fundamentally new and important properties.
The setting time of gypsum depends on many technological factors.
From the above data, it can be seen that the addition of B practically does not affect the water-gypsum ratio.
Effect of chemical modifying additives on the setting rate and other properties of the gypsum composition Experience No.
The softening factor is 0.70, which indicates its high water resistance.
The setting time of gypsum depends on many technological factors.
From the above data, it can be seen that the addition of B practically does not affect the water-gypsum ratio.
Effect of chemical modifying additives on the setting rate and other properties of the gypsum composition Experience No.
The softening factor is 0.70, which indicates its high water resistance.
Modeling of High Speed End Mills Based on Simulation of Dynamic Cutting Forces and Safety Prediction
Online since: December 2007
Authors: H.Z. Ma, Yu Juan Huang, Bin Jiang, Min Li Zheng
The rigidity failure rotational speed is higher the
strength failure rotational speed, the connection strength between cutter body and screw bolt affects
directly the safety of cutter.
The periodic change in cutting force affects directly machining quality, machining efficiency, and the reliability of high speed end mills [3, 4].
According to the property of the Dirac Function, Fx(t) and Fy(t) are transformed by Fourier Transform [10], we can construct the frequency spectrum functions of dynamic cutting forces dte(t)F(f)P ft2j x ox π− +∞ ∞−∫ ⋅= , dte(t)F(f)P ftj2 y oy π− +∞ ∞−∫ ⋅=
The number of teeth participating in cutting, the rake of cutter, and cutting parameters are important factors affecting the safety and high speed milling performance.
Wan: China Mechanical Engineering, Vol.14 (2003), pp.734
The periodic change in cutting force affects directly machining quality, machining efficiency, and the reliability of high speed end mills [3, 4].
According to the property of the Dirac Function, Fx(t) and Fy(t) are transformed by Fourier Transform [10], we can construct the frequency spectrum functions of dynamic cutting forces dte(t)F(f)P ft2j x ox π− +∞ ∞−∫ ⋅= , dte(t)F(f)P ftj2 y oy π− +∞ ∞−∫ ⋅=
The number of teeth participating in cutting, the rake of cutter, and cutting parameters are important factors affecting the safety and high speed milling performance.
Wan: China Mechanical Engineering, Vol.14 (2003), pp.734
Online since: October 2014
Authors: Wacław Banaś, Aleksander Gwiazda, Zbigniew Monica, Agnieszka Sękala
Introduction
Increasing customer demands, shorter product life cycles, balancing between production costs and the quality level and punctuality of orders and finally strong competitive struggle, are factors, with which have to face companies operating in changing market conditions [1,2,3].
One of important elements of the new model is determining the material parameters that affect the process of designing new technology and production layout [14,15,16,17].
Next investigation should include the presented above problems to elaborate the comprehensive and complex MAS for designing production layout and problems considered with the mechanical properties of manufactured products [20,21].
Topolska, The effect of long-term service at elevated temperatures on structure and mechanical properties of Cr-Mo-V steel, Journal of Achievements in Materials and Manufacturing Engineering 49/1 (2011) 33-39
Sȩkala, Vibration analysis of mechanical systems with the discrete-continuous distribution of parameters, Solid State Phenomena 198 (2013) 698-703.
One of important elements of the new model is determining the material parameters that affect the process of designing new technology and production layout [14,15,16,17].
Next investigation should include the presented above problems to elaborate the comprehensive and complex MAS for designing production layout and problems considered with the mechanical properties of manufactured products [20,21].
Topolska, The effect of long-term service at elevated temperatures on structure and mechanical properties of Cr-Mo-V steel, Journal of Achievements in Materials and Manufacturing Engineering 49/1 (2011) 33-39
Sȩkala, Vibration analysis of mechanical systems with the discrete-continuous distribution of parameters, Solid State Phenomena 198 (2013) 698-703.
Online since: December 2013
Authors: Mei Ling Huang, Zhao Yu Fu
So Green High Performance Concrete is the modern concrete inevitable result of technological development, it is the development direction of the concrete.
1.2 Research Progress of Green High Performance Concrete
Under the premise of the mechanical properties of concrete,Green High Performance Concrete highlight two aspects of energy saving and emission characteristics.
Mechanical properties should be studied after preparation of a recycled aggregate concrete, in order to make reasonable and effective use of recycled aggregate concrete.
The method of measurement is the same as the normal concrete’s. 2.2.3 Durability index External influencing factor of recycled concrete’s durability are carbonization, freeze thawing, Permeability and fatigue loading, and so on,and internal influencing factors is mainly the mix proportion,the effect of cement-based materials’s physical and chemical changes and alkali-aggregate reaction(AAR) and so on
But in China,green concrete research is still in its infancy at present , and only a few units do a preliminary study of its properties and applications .
[9] Ippei M,Masaru S,Takahisa S,etal.Flexural properties Of reinforced concrete betas[C].
Mechanical properties should be studied after preparation of a recycled aggregate concrete, in order to make reasonable and effective use of recycled aggregate concrete.
The method of measurement is the same as the normal concrete’s. 2.2.3 Durability index External influencing factor of recycled concrete’s durability are carbonization, freeze thawing, Permeability and fatigue loading, and so on,and internal influencing factors is mainly the mix proportion,the effect of cement-based materials’s physical and chemical changes and alkali-aggregate reaction(AAR) and so on
But in China,green concrete research is still in its infancy at present , and only a few units do a preliminary study of its properties and applications .
[9] Ippei M,Masaru S,Takahisa S,etal.Flexural properties Of reinforced concrete betas[C].
Online since: January 2013
Authors: Marcel Horák, František Novotný, Martin Plavec
WORKING ENVIRONMENT INFLUENCES
Fig. 1 Overview of system connections of the mobile platform MP 02
It is obvious that the robot optimal functioning is affected significantly by the concept of a kinematical chain, drives, control, method of measurement, and holding system which is consequently a determining factor for safety parameters fixing; these parameters are further connected with the robot dynamic behaviour, characteristics of the objects creating the contact plane, layout as well as with the operating staff role during its operation.
From the standpoint of the mechanical connection complexity, higher weight of the chassis drive, and the frame eccentric loading when placing the drive off the chassis axis, the drive allowing the frame to be rotated owing to the frame was placed axially.
On the one hand, the carrying capacity is given by size and number of the suction cups creating the holding system, which has its limits with respect to a vacuum source, pneumatic vacuum circuit, and frame design; on the other hand it is given by mechanical properties of the façade system which is limited by maximum external loading, and also a distance degree of the service robot mass centre from the contact plane; this distance tells negatively on the additional load of the individual suction cups as a result of the tilting moment incurred.
Fig. 5 Stress and deformation fields in the frame without ribs having the connecting plate 6 mm thick Fig. 6 Stress and deformation fields in the optimized frame Summary Analysing the results of operational tests of the first-generation mobile platform of the service robot during its motion on the vertically oriented glass wall, main parameters were determined affecting the mobile platform reliability performance with respect to the motive activities, manoeuvrability, and operational safety.
Y., Lee K., Development of a wall-climbing robot using a tracked wheel mechanism, Journal of Mechanical Science and Technology22 (2008), 1490-1498 DOI 10.1007/s12206-008-0413-x [7] Albagul1 A., Asseni1A., Khalifa O., Wall Climbing Robot: MechanicalDesign and Implementation, In: Proc.
From the standpoint of the mechanical connection complexity, higher weight of the chassis drive, and the frame eccentric loading when placing the drive off the chassis axis, the drive allowing the frame to be rotated owing to the frame was placed axially.
On the one hand, the carrying capacity is given by size and number of the suction cups creating the holding system, which has its limits with respect to a vacuum source, pneumatic vacuum circuit, and frame design; on the other hand it is given by mechanical properties of the façade system which is limited by maximum external loading, and also a distance degree of the service robot mass centre from the contact plane; this distance tells negatively on the additional load of the individual suction cups as a result of the tilting moment incurred.
Fig. 5 Stress and deformation fields in the frame without ribs having the connecting plate 6 mm thick Fig. 6 Stress and deformation fields in the optimized frame Summary Analysing the results of operational tests of the first-generation mobile platform of the service robot during its motion on the vertically oriented glass wall, main parameters were determined affecting the mobile platform reliability performance with respect to the motive activities, manoeuvrability, and operational safety.
Y., Lee K., Development of a wall-climbing robot using a tracked wheel mechanism, Journal of Mechanical Science and Technology22 (2008), 1490-1498 DOI 10.1007/s12206-008-0413-x [7] Albagul1 A., Asseni1A., Khalifa O., Wall Climbing Robot: MechanicalDesign and Implementation, In: Proc.
Online since: January 2021
Authors: Zhi Guo Gao
The useful model is also applicable to other single-crystal superalloys with similar metallurgical properties by laser welding or laser cladding, and provide a more accurate and reliable way of solidification cracking susceptibility evaluation.
Introduction γˊ gamma prime and γˊˊ gamma double prime precipitation-strengthened nickel-based superalloy and derivative are widely used in aerospace industries because of excellent high-temperature mechanical properties, corrosion resistance and thermal stability, however, the weldability is still challenge because of high susceptibility to solidification cracking.
Severe weldability is significantly reduced by proper control of metallurgical factors for solidification cracking in order to satisfy the increasing requirement of performance and weld quality.
The material properties in the calculation are available in the literature [23-26].
Fig.2 Dendrite selection (a), dendrite trunk spacing (b) and solidification temperature range (c) in the (001) and [100] welding configuration, dendrite selection (d), dendrite trunk spacing (e) and solidification temperature range (f) in the (001) and [110] welding configuration (laser power 5kW, welding speed 4m/min) Both metallurgical factors improve the weldability under nonequilibrium solidification conditions.
Introduction γˊ gamma prime and γˊˊ gamma double prime precipitation-strengthened nickel-based superalloy and derivative are widely used in aerospace industries because of excellent high-temperature mechanical properties, corrosion resistance and thermal stability, however, the weldability is still challenge because of high susceptibility to solidification cracking.
Severe weldability is significantly reduced by proper control of metallurgical factors for solidification cracking in order to satisfy the increasing requirement of performance and weld quality.
The material properties in the calculation are available in the literature [23-26].
Fig.2 Dendrite selection (a), dendrite trunk spacing (b) and solidification temperature range (c) in the (001) and [100] welding configuration, dendrite selection (d), dendrite trunk spacing (e) and solidification temperature range (f) in the (001) and [110] welding configuration (laser power 5kW, welding speed 4m/min) Both metallurgical factors improve the weldability under nonequilibrium solidification conditions.