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On the basis of the research, the improvement of mechanical and tribological properties for friction pairs with addition of those elements was proven.
The adopted parameters for the studies of tribological properties were set based on numerous tests performed at the Faculty of Mechanical Engineering of the University of Zielona Gora.
Modifying the lubricant resulted in the improvement of its anti-wear properties. 4.
Unlu, Investigation of tribological and mechanical properties of metal bearings.
Atik, Evaluation of effect of alloy elements in copper based CuSn10 and CuZn30 bearings on tribological and mechanical properties.

Their effects were investigated in terms of the microstructure, using positron annihilation lifetime techniques and mechanical properties monitoring via Vickers hardness measurements.
Its strength is affected by the presence of Mg2Si in various forms.
These characteristics, as is well known, largely determine the mechanical, electrical and magnetic properties of metals [2, 3, 5, and 7].
The changes in mechanical properties were measured using the Vickers hardness method; the standard method for measuring the hardness of metals, particularly those with extremely hard surfaces. 3.
[18] ASTM Standard, B557M Tension Testing Wrought and Cast Aluminum and MagnesiumAlloy Products, (2002) [19] Cai, M., Field D.P. and Lorimer G.W., A Systematic Comparison of Static and Dynamic Ageing of Two Al-Mg-Si Alloys, Materials Science and Engineering A, 373, (2004) 65-71 [20] Chakrabarti, D.J. and Laughlin, D.E., Phase Relations and Precipitation in Al-Mg-Si Alloys with Cu Additions, Progress in Materials Science, 49 (2004) 389-410 [21] Dorward, R.C. and Bouvier, C., A Rationalization of Factors Affecting Strength, Ductility and Toughness of AA6061-Type Al-Mg-Si-(Cu) Alloys, Materials Science and Engineering A, 254 (1998) 33-44 [22] Hirth, S.M., Marshall, G.J., Court, S.A. and Lloyd, D.J., Effects of Si on the Aging Behavior and Formability of Aluminium Alloys Based on AA6016, Materials Science and Engineering A, 319- 321 (2001) 452-456 [23] M.

Residual stress theory.It is a theoretical and not consider shrinkage factor residual stress theory and consider shrinkage factors, amended residual stress theory.　
It combines the characteristics of rubber and thermoplastics, having a good appearance of texture, excellent abrasion resistance ,tensile properties and adhesion properties, as well as suitable for printer board.
Effect degree analysis of process parameters on the warpage The experiments studied on warpage impact factors of printer board with metal-insert,numerical simulation and theoretical analysis,.Effect degree of products warpage trend in different locations and process parameters are different.In order to get comprehensively the primary and secondary influence factors of warpage on the products,introduce dimensionless factor λ and influence coefficient η,as given below[8]: (4) where, and are the value and initial value of affecting factors respectively, and are the different positions and initial different positions warpage amounts respectively,unit mm.
Through the above analysis, each factors impact coefficient map of product warpage is shown in Fig. 9.
the four factors affecting products warpage, the melt temperature had the greatest influence, followed by the mold temperature and packing pressure, packing time minimal effects on products warping deformation.

This research aims to provide theoretical proof for the further study on the factors of stress relaxation under different conditions.
Some researchers have studied the viscoelasticity of wood: Fushitani [3, 4] studied the stress relaxation of swelling wood, and thought that temperature was one of important factors affected wood stress relaxation; Bonefied [5] studied the wood under tensile stress relaxation and Rawat [6] studied compression stress relaxation of wood; Backman and Lindberg [7] measured the dynamic viscoelasticity of Pinus sylvestris L. in radial direction and tangential direction.
So it plays a key role in rheological property [8].
Because of different materials and formative conditions, early and late wood must have different physical and mechanical properties.
Summary This research aims to provide theoretical proof for the further study on the factors of stress relaxation under different conditions.

Related works on LMD-p on Ti-6Al-4V show that raw materials, process parameters, building strategies and post-treatments directly affect the final part properties (microstructure, defects, mechanical properties).
Some authors showed the influence of the chosen deposition pattern on the mechanical properties [3,8].
These treatments, since they have an impact on microstructure, defects and internal stress, influence the mechanical properties of the AM part [10,11].
In general, they are used to increase the mechanical properties.
The dilution rate is directly related to the parameters and combination factors.

However, it is difficult to weld because it have lots of factors, which is limited to welding, such as the low melting point, the low evaporation point, the high chemical attraction with oxygen and the generation of metal compound.
Table 1 Chemical composition and mechanical properties of Mg alloys.
This occurs due to the mechanical deformation in TMAZ of FSW.
Table 3 Physical properties of FSWelded Mg Alloys Yield strength (MPa) Tensile strength (MPa) Elongation (%) AZ31B-H24 93 230 10.24 AZ61A-F 123 210 7.6 AZ91C-F 109 166 3.4 Figure 10 shows the fracture appearance of joints.
Because of more Mg17Al12 (β phase) intermetallic compounds, Mg alloy with high Al content showed poor mechanical properties.

A Study on Ductility of Lightweight Aggregate Concrete Shear Wall Weichao Chen1,2, a, Weijun Yang1, b, Yao Li1,c 1Changsha University of Science and Technology, Hunan Changsha 410076, China 2Hunan Construction Engineering Group Corporation, Hunan Changsha 410004, China awlrwc@163.com, bmgbyrh@163.com, c370324236@qq.com Key words: lightweight aggregate concrete, shear wall, ductility Abstract: Based on the properties of lightweight aggregate concrete, the yield curvature and the ultimate curvature are calculated by numerical method, and the relationship between curvature ductility ratio and displacement ductility ratios is established for lightweight aggregate concrete shear wall.
The major influencing factors for ductility of lightweight aggregate concrete shear wall include with or without constrain edge conponent, the characteristic value of stirrup of constrain edge conponent, the axial compression ratio and the height-width ratio and so on.
Introduction Although many experimental researches were conducted of seismic behavior on light weight concrete shear wall in recent years, the researches for the ductility design, the factors and the calculation method of ductility of light weight concrete shear wall were rarely reported.
(2) There are many factors can affecting the displacement ductility of light weight aggregate concrete shear wall,but the only effective way is to limit axial compression ratio and set constraint edge conponent
(3) According to the numerical calculate method on displacement ductility ratio of light weight aggregate concrete shear wall and the affecting factors, and the requirements of the code for seismic design of buildings, the limit value for the axial compressive ratio and the haracteristic value for hoop of constraint edge component of light weight aggregate concrete shear wall still need further research.

In all cases, it is helpful to established a theoretical link between the functional properties of the surface and its micro- physiognomy[2].
As a material removal process, there are two key factors in the grinding process to affect the surface performance: the geomorphology of the wheel and the chip formation process involved[3], which considers the interaction of the workpiece surface and the abrasive grains.
As the technology of SHSP grinding emerges, the angle of α has changed the contact area between the wheel and the cylindrical workpiece, which could be attained through analyzing the grinding parameters affecting it.
According to the application rang of SHSP grinding, the value of α is set to ±0.5°, which is the main factor to affect the contact area to be increased.
The surface quality has been improved in theory based on the number of cutting from effective particles in SHSP grinding while grinding in the same wheel speed and other factors compared to SHS grinding.

Introduction In sheet metal forming processes, the geometrical accuracy as well as the final mechanical properties of the finished part is influenced by diverse factors (Fig. 1).
The functional applications of these elements such as fixation, motion and load transmission require compliance with high geometrical accuracy as well as high precision regarding the final mechanical properties of the part.
Affecting the process stability, the machine properties need to be considered in the process layout, otherwise leading to non-compliance with demanded quality tolerances of the manufactured parts. 100 FZ FY FX DC04 0 4 8 12 16 20 24 28 32 36 punch stroke [mm] forming force [kN] 0 -100 -300 -400 -500 -600 -700 -800 -200 FZ FY FX DP600 0 4 8 12 16 20 24 28 32 36 Figure 4.
The defined force application allows an accurate determination of the machine properties.
To improve the computational accuracy of process modelling a suitable approach has been presented to take into account the machines properties.

Abstract: The performance of a tunnel is influenced by such factors as the size and shape of the opening, the in-situ stress and the deformation field and also properties of the rock mass.
The numerical results indicate that the mechanical index is different due to variant excavation plans and an optimized plan is determined based on the comprehensive analysis of the index gained from the simulation results.
This paper attempts to demonstrate how the excavation procedure affects the tunnel performance using flac3D.
However, the determination of the best excavation procedure should take consideration of many factors such as the horizontal displacement of straight walls, the uplift of the bottom and energy release rate.
Further research work should be done taking account of the other factors in order to make the most rational decision.