Search results

The results of the studies of structure, critical current density, trapped field and mechanical characteristics are discussed.
Recently (in 2001) the superconductive properties of MgB2 were examined.
The Vickers microhardness was estimated using a 1.96 N load and can give a notion of mechanical properties of the material as a whole.
The correlation between the amount of Mg-B (MgB2) inclusions and increase of jc is not so strict because several factors affect the jc.
The Ti addition slightly reduces the material microhardness, while Ta addition increases mechanical properties.

Iron and steel matrix composites reinforced with TiB2/TiC ceramic particulates have been the focus of intensive investigation due to their ease of fabrication, low costs and isotropic properties.
For this reason, MMCs with fresh, ultrafine and stable ceramic reinforcements can demonstrate outstanding mechanical properties [6].
The second theme is the relationship between microstructural and mechanical properties, notably weldability and the ductile brittle transition temperature of these steel matrix composite (TiB2-RSMCs) sheets recently invented and developed by the ARCELOR Research Group in France [1].
In this case, observing the evolution of applied force with time provided more detailed information about the mechanical properties of each zone of the steel matrix composite.
impact tensile properties of the steels under crash test.

Thus is explained the important differences between the mechanical properties of wood in parallel and perpendicular to the grain directions.
The mechanical properties of the softwood currently used for timber structures in Romania, with its different parallel to the grain, radial and tangential elasticity properties, aligned considering the structural elements longitudinal axes, are defined.
Regarding the mechanical properties of the material, in the analysis were defined only parallel to the grain wood`s elasticity modulus of 11.30 GPa and the shear modulus of 5.00 GPa.
The transversal cross-sections geometry and material properties were assigned to each structural element.
These are the major factors that lead to important differences between the external forces applied to the structure and, consequently the stresses that occur in the structural elements.

Analysis on Circumferential Clearance of Four-Ball-Pin Constant Velocity Joint Yang Hong-Xing1, a, Guo Chang-Ning1,b and Shi Bao-Shu3,c 1School of Mechanical Engineering,Shanghai Jiao Tong University, Shanghai 200240,China 2Zhejiang Zhong Da Transmission Co., Ltd, Jinhua 321025,China ayhxshine@sjtu.edu.cn, bchnguo@sjtu.edu.cn, cmyy968@sina.com Keywords: Four-Ball-Pin constant velocity joint, Tripod constant velocity joint, Circumferential clearance Abstract: By using Matlab, the circumferential clearance changing law with any swing angle and rotating angle of four-ball-pin CVJ was obtained, the results show that, under the same size specification and machining accuracy, four-ball-pin CVJ has a roughly similar vibration amplitude with traditional tripod CVJ, when the CVJ rotates one circle at any swing angle, there are four fluctuations of circumferential angle in four-ball-pin CVJ, but there six fluctuations in tripod CVJ, so the former one fluctuate less and has much more slight
Composed of two or one set of constant velocity universal joints, intermediate shaft, and other components, the mechanical part is usually used to transmit motion and torque.
Motion model Due to the factors such as design tolerances and machining errors etc, clearances exist among components of a CV.Joint after being assembled.if the circumferential clearance of the CVJ is too large, the internal components of the CV.Joint can generate shock, noise, thus this clearance can affect the reliability and lifetime of the CVJ severely.
The property of a CV Joint can therefore affects the stability and comfort of a car directly.The analysis on circumferential clearance of CVJ and influencing factors from the internal structure can be used to improve the product design and manufacture of craft, and to improve the comprehensive properties of future products as well.

Because of these, it is difficult to deformation in the initial stage of compressive, so its initial cushioning properties is poor.
So in this local stage the cushioning properties of RHP are better than HHP.
The height of RHP is little influence on its cushioning properties.
In contrast, the cell-wall length is an important factor to influence the compression properties, with the increasing of the cell-wall length, the critical load of RHP will reduce obviously.
In-depth study on the mechanical behavior, such as edgewise compressive strength, creasing and folding property, and dynamic cushioning property and so on, will be essential before widely applying the newly developed rhombic honeycomb paperboard.

Study on the Formability Rules with Precise Die Face for the Inner Clutch shell of Automobile Beyene Gezae Mebrahtu1,a, Cai Yujun2,b, and Yu Qiang3,c 1,2,3 Tianjin University of technology and education, School of Mechanical engineering, Tianjin, China agezae2020@gmail.com, bcyjal@126.com, cyuqiang95@yeah.net Keywords: Rule of precise, simulation, FEM, Wrinkle, sheet metal forming, die face Abstract.
Finally compute all simulation results with reference to the original part property and recommend the appropriate process flow to produce the part, the comparison with tryout results shows that the formality simulation of thick panel with precise die face is reliable and accurate.
Table 1- Main parts of the three processes Model for Die Punch Binder Draw 1st Flange 2nd Flange The material chosen for the analysis was Material-Type 36 in DAYNAFORM: QC mild steel which properties are consistent with the real one.
The following picture shows us the whole process flow for inner clutch shell Draw First Trim First flange Second trim Second flange Fig. 4 Process flow Numerical Results Wrinkling is affected by many factors, such as process parameters, contact conditions, mechanical properties and geometry of the blank.

Within the scope of this paper, the influence of contact area and surface pressure on the frictional properties during forming is studied.
State of the Art Major factors affecting friction include the normal stress along the tool and workpiece interface, the lubrication condition, the relative velocity, the temperature, the roughness, and the mechanical properties of the material and/or the tool.
A detailed investigation of these factors is demanding since the tool and workpiece interface in metal forming is usually under high pressure.
The amount of lubricants which can be stored in a micro dimple depends on geometric properties (width, depth, shape) of the indentation.
Results and Discussion In order to investigate the effect of contact area on friction properties, an experimental matrix is defined.

The research has shown that the most convenient microstructure variables in the austenitic crystals of polycrystalline sample, affecting the microcrack deviation, are microstructure, crystallography and the homogenous length of slip bands.
From the analyses, we have carried out, follows that in the physical model of plasticity of polycrystalline materials the major factors are the process parameters (amplitude, frequency, temperature) as well as the crystallography of slip, deformation twinning and crack formation.
In this regard, a scale factor should necessarily be taken into account, since for large bodies brittleness increases while for small ones it decreases.
Starting from the above considerations, the scale factor acquires a significant importance for thinning of samples (mainly of TEM samples), while in this case internal stresses relax faster.
Such kind of study and accumulation of statistical data, will definitely contribute to the design of alloys with the improved physical and mechanical properties.

The main synthesis parameters such as water to the geopolymer solid ratio, alkali to cementitious ratio and molarity of NaOH were varied to understand their individual effect on setting time and the mechanical properties of the resulting geopolymer.
The calcium oxide gives fly ash pozzolanic properties and, relatively shorter setting times.
Fresh and hardened properties of geopolymer concrete are affected by several factors such as alkaline liquid to fly ash ratio, NaOH concentration, the ratio of alkaline solutions, curing conditions, and admixtures [10].
Most of the reports [11,12,13] on the properties of geopolymer concrete were based on low-calcium fly ash.
[2] J.G.S.D. van Jaarsveld, Effect of the alkali metal activator on the properties of fly ash-based geopolymers, Ind.

It was concluded that the ageing of polymer dielectrics affected by electric microseconds impulses did not relate to volume charge accumulation in the polymers.
In the process of insulation use, the long-term influence of the operating voltage, as well as the number of other factors (temperature, mechanical loadings, environment, radiation and others) can result in its ageing.
The interconnection and interdependence of the influence of the ageing factors hinder the insulation ageing investigation.
A number of works points out the participation of macrostructure defects (cavities, where the partial discharges are developed) [3, 4], as well as the environmental factors [5].
Bonnet, Investigation on electrical properties of thermally aged PMMA by combined use of FTIR and impedance spectroscopies, J. of Alloys and Compounds, 469 (2009) 197–202