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Online since: June 2012
Authors: Nazym Smagulova, Aubakirov Ermek, Elmira Yermoldina, Zhaxsyntay Kairbekov
Road pavements based on sulfurbitumen composites have higher mechanical indicators and durability compared to traditional binders.
Physical-mechanical indicators and duration of operation of road pavements obtained from the mixture of sulfurized bitumen are better than in bitumens obtained from traditional sources.
Physical-mechanical indicators of sulfurized bitumen Indicators Bitumen of «coal oil» Bitumen of mark BND60/90 Methods of testing Penetration, 250C, 0.1 mm 64 60-90 GOST 11501 Temperature of softening according to K and Sh, 0C 44 47-51 GOST 11506 Temperature of fragility (Fraas), 0C -30 -18 GOST 11507 Index of penetration -1.1 GOST 22245 Interval of plasticity 77.7~780 C Physical-chemical indicators of obtained bitumen completely correspond to conditions of the standard, which can be compared to the viscous road oil bitumen of mark BND60/90.
Conclusion Thus, the clusters of sulfur, entering the dispersive media, affect the regularity of its structure leading to positive phenomena of interdisk lubrication of asphaltene aggregates, which leads to the increase of plasticity and elasticity of composites.
[2] Vasilyeva I.I., Kazina N.G., Effects of sulfur on properties of oil bitumens.
Physical-mechanical indicators and duration of operation of road pavements obtained from the mixture of sulfurized bitumen are better than in bitumens obtained from traditional sources.
Physical-mechanical indicators of sulfurized bitumen Indicators Bitumen of «coal oil» Bitumen of mark BND60/90 Methods of testing Penetration, 250C, 0.1 mm 64 60-90 GOST 11501 Temperature of softening according to K and Sh, 0C 44 47-51 GOST 11506 Temperature of fragility (Fraas), 0C -30 -18 GOST 11507 Index of penetration -1.1 GOST 22245 Interval of plasticity 77.7~780 C Physical-chemical indicators of obtained bitumen completely correspond to conditions of the standard, which can be compared to the viscous road oil bitumen of mark BND60/90.
Conclusion Thus, the clusters of sulfur, entering the dispersive media, affect the regularity of its structure leading to positive phenomena of interdisk lubrication of asphaltene aggregates, which leads to the increase of plasticity and elasticity of composites.
[2] Vasilyeva I.I., Kazina N.G., Effects of sulfur on properties of oil bitumens.
Online since: February 2013
Authors: Gheorghe Oancea, Sever Alexandru Haba
Fig. 1 CATIA Mechanical Design – Assembly, generative structural analysis
- engine clamps
Fig. 2 CATIA Analysis&Simulation – Design,
assembly engine block.CATPart
In order to complete the necessary analysis data, the following conditions have to be used[5]:
· finite element type (linear or nonlinear);
· finite element size;
· maximum allowable geometric error (SAG);
· clamps are necessary for cancellation degrees of freedom of assembly (DOF), presented in the Fig. 2;
· geometric constraints is set to obtain all assembly parts (Assembly Design Mode) and to apply simulation constraints necessary for contact internal links between parts in contact, the pair of surfaces is determined by properties of the contact set “smooth connection” [5];
· heating temperature is set value of all the bodies studied (Static Case – Loads – Temperature Field);
· ambient temperature is set at 20 Celsius degrees (environment);
· type of analysis is chosen Gauss R6;
· type of finite
The results of the finite elements analysis are influenced by the user experience, that sets the input parameters required, the accuracy of the correspondence between the real and the simulated phenomenon is affected by the establishment of the restrictions in an improper way or by the conditions of interaction between surfaces in contact [5].
Lightweight engines are based on several main design and construction principles such as: · assembly of engine blocks made of light alloy and cylinder casing with high hardness; · high resistant surfaces achieved by depositing metal films directly on the walls of the engine block made of light alloys; · realization of the engine block with variable wall thickness, the constraint factor imposed is the weight [8].
[2] Jarruwant Chareonsuk, Passakon Vessakosol, Numerical solution for functionally graded solids under thermal and mechanical loads using a high-order control volume finite element method, Applied Thermal engineering, Volume 31, Issue 2-3 (2011) 213-227
Ghionea, CATIA V5 Applications in mechanical engineering, Bren Publishing, Bucharest, Romania, 2007
The results of the finite elements analysis are influenced by the user experience, that sets the input parameters required, the accuracy of the correspondence between the real and the simulated phenomenon is affected by the establishment of the restrictions in an improper way or by the conditions of interaction between surfaces in contact [5].
Lightweight engines are based on several main design and construction principles such as: · assembly of engine blocks made of light alloy and cylinder casing with high hardness; · high resistant surfaces achieved by depositing metal films directly on the walls of the engine block made of light alloys; · realization of the engine block with variable wall thickness, the constraint factor imposed is the weight [8].
[2] Jarruwant Chareonsuk, Passakon Vessakosol, Numerical solution for functionally graded solids under thermal and mechanical loads using a high-order control volume finite element method, Applied Thermal engineering, Volume 31, Issue 2-3 (2011) 213-227
Ghionea, CATIA V5 Applications in mechanical engineering, Bren Publishing, Bucharest, Romania, 2007
Online since: February 2009
Authors: Bo Zhang, Wu Yi Chen, Dong Liu
Experimental Study on the Cutting Temperature Using Work-tool
Thermocouple while Machining TC4
ZHANG Bo
1,2,a, CHEN Wu-yi 2,b, LIU Dong 3,c
1Mechanical and Electrical Dept,China University of Mining & Technology (Beijing),Beijing
100083,China;
2
School of Mechanical Engineering and Automation, Beihang University, Beijing, 100083,China;
3
College of Mechanical Electronical and Engineering,North China University of Technology, Beijing,
100041,China;
a
bobo1107@sina.com,
bwychen@buaa.edu.cn,
cliudong@ncut.edu.cn
Keywords: Natural thermocouple; Cutting temperature; Titanium alloy; Calibration;TC4
Abstract.
Introduction Titanium alloys are widely used in aerospace industry due to their excellent mechanical properties.
According to the interspace conductor law of the thermoelectricity, if the junction of two metals is at a uniform temperature, the emf generated is not affected by a third metal, which is at the same temperature, used to make the junction between the first two.
The amplifier factor channel 1 was 320 times, the channel 2, channels 3 is 100 times.
Introduction Titanium alloys are widely used in aerospace industry due to their excellent mechanical properties.
According to the interspace conductor law of the thermoelectricity, if the junction of two metals is at a uniform temperature, the emf generated is not affected by a third metal, which is at the same temperature, used to make the junction between the first two.
The amplifier factor channel 1 was 320 times, the channel 2, channels 3 is 100 times.
Online since: November 2012
Authors: Y. Varthamanan, V. Kannan
Moore's law describes a driving force of technological and social change in the late 20th and early 21st centuries [2].Numerous innovations by a large number of scientists and engineers have become significant factors in the sustenance of Moore’s law since the beginning of the integrated circuit era.
In most approaches, a hybrid technology is envisioned, where Si still remains the handling substrate for fabrication processing, heat transport, and mechanical support purposes, with a new semiconductor integrated on the top for enhanced device operations or added new functionalities.
The unique electron transport properties and band structure of nano tubes.
They have attracted much of an attention recently because of their remarkable electronic and mechanical properties[1].
These densities are determined by the Fermi-Dirac probability distribution: (2) (3) (4) Where, D(E) is the density of states, f is the Fermi probability distribution, E represents the energy levels per nanotube unit length, and USF and UDF are defined as USF = EF - qVSC (5) UDF = EF - qVSC - qVDS (6) Where, EF is the Fermi level, q is the electronic charge and VSC represents the self-consistent voltage whose presence in these equations illustrates that the CNT energy band is affected by external terminal voltages.
In most approaches, a hybrid technology is envisioned, where Si still remains the handling substrate for fabrication processing, heat transport, and mechanical support purposes, with a new semiconductor integrated on the top for enhanced device operations or added new functionalities.
The unique electron transport properties and band structure of nano tubes.
They have attracted much of an attention recently because of their remarkable electronic and mechanical properties[1].
These densities are determined by the Fermi-Dirac probability distribution: (2) (3) (4) Where, D(E) is the density of states, f is the Fermi probability distribution, E represents the energy levels per nanotube unit length, and USF and UDF are defined as USF = EF - qVSC (5) UDF = EF - qVSC - qVDS (6) Where, EF is the Fermi level, q is the electronic charge and VSC represents the self-consistent voltage whose presence in these equations illustrates that the CNT energy band is affected by external terminal voltages.
Online since: October 2014
Authors: Yan Cui
There are many causes for the crack of cladding layer and also there are many factors to affect.
At present, most of the materials for cladding are with high strength, hardness, and brittleness in terms of the mechanical industry.
However, these materials are greatly different from each other in performance, properties, and basic components, mainly because their linear expansion coefficients are greatly different, and the solid phase transformation tendency and amplitude vary largely in the crystallization process and also the solid-state phase transformations are out of sync.
Second, the mismatch between the internal properties and technologies of cladding material and base material was one of the important causes of the cladding layer’s crack.
Beijing: Mechanical Industry Publishing House, 2005.
At present, most of the materials for cladding are with high strength, hardness, and brittleness in terms of the mechanical industry.
However, these materials are greatly different from each other in performance, properties, and basic components, mainly because their linear expansion coefficients are greatly different, and the solid phase transformation tendency and amplitude vary largely in the crystallization process and also the solid-state phase transformations are out of sync.
Second, the mismatch between the internal properties and technologies of cladding material and base material was one of the important causes of the cladding layer’s crack.
Beijing: Mechanical Industry Publishing House, 2005.
Online since: June 2010
Authors: Tian Yong Deng, Chun Lin Qiu, Hao Ran Wang, Ke Min Qi, Ping Zhou, Xiu Hua Gao
Introduction
Gear steel is widely used in automobile, agricultural machine and mechanical manufacture industries
[1].
It directly affects mechanical performance of automobile gear.
Evaluation of hardenability makes it possible to obtain the required properties before production.
During the process of composition adjustment, the properties of gear steel can be predicted by means of ANN or stepwise polynomial regression any time.
However, the simple mathematics regression model can't reflect the inherent rules between the hardenability and its influence factors.
It directly affects mechanical performance of automobile gear.
Evaluation of hardenability makes it possible to obtain the required properties before production.
During the process of composition adjustment, the properties of gear steel can be predicted by means of ANN or stepwise polynomial regression any time.
However, the simple mathematics regression model can't reflect the inherent rules between the hardenability and its influence factors.
Online since: January 2012
Authors: Mário Gajdoš, Andrej Berdis, Ján Gecák, Milan Mičko, Tadeaš Kurilovský
Companies in this way of heat treatment at high temperature is applied as the only way to increase the machinability because it improperly considered that also in this case, the reduction in mechanical properties (Re, HB), an improvement the machinability, [8].
Complex effect of all these factors necessarily requires a reduction in cutting conditions, especially the cutting speed by 4 times to 6 times compared with those elected in carbon steels.
As shown in Fig.2, the slip line field affects not only the zone of plastic deformation but also the layer below the machined surface.
The conclusions are as follows: defining of the shear plane angle F1 and the texture angle F2, confirmation of surface strain hardening (change in mechanical properties) after cutting.
Complex effect of all these factors necessarily requires a reduction in cutting conditions, especially the cutting speed by 4 times to 6 times compared with those elected in carbon steels.
As shown in Fig.2, the slip line field affects not only the zone of plastic deformation but also the layer below the machined surface.
The conclusions are as follows: defining of the shear plane angle F1 and the texture angle F2, confirmation of surface strain hardening (change in mechanical properties) after cutting.
Online since: October 2006
Authors: Hyo Seon Park, Hong C. Rhim, H.M. Lee, J.H. Seo, Y.H. Kwon
The structural responses are obtained from a structural analysis
model with reasonable assumptions including the mechanical properties of the material, the
dimensions of the members, locations and performance of connections between members.
In addition, accumulated fatigue over an elapsed period of time, unexpected load, and other factors can cause variations in mechanical performance of members and interface areas.
LiDAR (Light Detection And Ranging), which is currently used in GIS field and sometimes called ALS (Airborne Laser Scanning), can be used to obtain three-dimensional location information on an entire building or structure, but not a particular location, without being affected by the environment [6].
For proper application of the least square method, the shape of the structure to be monitored, load pattern, material properties, and the shape of cross-section should be considered.
In addition, accumulated fatigue over an elapsed period of time, unexpected load, and other factors can cause variations in mechanical performance of members and interface areas.
LiDAR (Light Detection And Ranging), which is currently used in GIS field and sometimes called ALS (Airborne Laser Scanning), can be used to obtain three-dimensional location information on an entire building or structure, but not a particular location, without being affected by the environment [6].
For proper application of the least square method, the shape of the structure to be monitored, load pattern, material properties, and the shape of cross-section should be considered.
Online since: October 2016
Authors: Mitsuyoshi Nomura, Yong Bo Wu, Si Si Li
However, it is also classified as an extremely difficult to machine material owing to its several inherent properties, e.g., low thermal conductivity, high specific strength and exceptional resistance to corrosion {E.O.
However, titanium alloy Ti-6Al-4V is very difficult to grind because of its inherent properties such as the ability to retain high strength at elevated temperatures and low thermal conductivity [4].
Electrochemical grinding (ECG), which utilizes both mechanical and electrochemical actions to remove material, is a promising way to reduce tool wear and improve grindability.
Then the oxygen layer is removed by abrasive grains for the sake of mechanical actions.
Zaborski S. [9] has studied different forms of cathode wear in ECG and presented the crucial factors influencing on their wear.
However, titanium alloy Ti-6Al-4V is very difficult to grind because of its inherent properties such as the ability to retain high strength at elevated temperatures and low thermal conductivity [4].
Electrochemical grinding (ECG), which utilizes both mechanical and electrochemical actions to remove material, is a promising way to reduce tool wear and improve grindability.
Then the oxygen layer is removed by abrasive grains for the sake of mechanical actions.
Zaborski S. [9] has studied different forms of cathode wear in ECG and presented the crucial factors influencing on their wear.
Online since: March 2011
Authors: Hai Sheng Li, Cody Bunger, Xue Nong Zou, Li Jin Zou, Zhi Yu Zhou
These components endowed COLLOSS® E with all the bone formation activities of osteoconductive, osteoinductive and osteogenic properties.
(b) Most mono-factors are only effective in very high concentrations.
Bioactivity.The ideal bone graft possesses the three properties of osteoconductivity, osteoinductivity, and osteogenicity [1].
Only autologous bone graft is qualified for all the three properties nowadays.
Although many factors have been verified to accelerate bone formation, how these factors do it and interact among them is still mysterious.
(b) Most mono-factors are only effective in very high concentrations.
Bioactivity.The ideal bone graft possesses the three properties of osteoconductivity, osteoinductivity, and osteogenicity [1].
Only autologous bone graft is qualified for all the three properties nowadays.
Although many factors have been verified to accelerate bone formation, how these factors do it and interact among them is still mysterious.