Search results

For solving the problem, various basic researches about the factors that influence cutting force in cutting procedures have been conducted, including tool geometry and cutting parameters .
Both of them affected the milling force extensively and were of considerable importance in orthopedic surgery.
Overheating would alter mechanical properties of living bone [8,9].
The meshes are assigned with the material and structural properties which define how the structure will react to certain loading conditions.
The reason of this phenomenon might be that shear angle increased with cutting speed increasing, plastic flow stress decreases; on the other hand, bone is sensitive to temperature, the temperature rise might change the mechanical properties.

Simulation and Optimization of a New Hydraulic Impactor Hongqiang Zhao1, 2, Peng Liu1,Minfei Shu1,Guochen Wen1 1School of Mechanical and Electrical Engineering, Central South University, Changsha, Hunan, 410083, China 2Sunward R&D Center, Xingsha Development Zone, Changsha, Hunan, 410100, China E-Mail: hewn123456@126.com Keywords: hydraulic impactor; dynamic mathematics numerical model; simulation; optimization.
This model facilitates accurate analysis of parameters affecting the property of impactor, thus providing a better design method for the optimization design of hydraulic impactor.
Its working progress complies with fluid motion and mechanical motion law, and is influenced and conditioned by a variety of factors.
According to the fluid motions and mechanical motion theory, the mathematical model can be built.
In order to analyze and solve problems conveniently, such appropriate hypotheses to the factors which are difficult to be fully considered but have little effect on the results of analysis are established: (1) Oil is incompressible and temperature is the same everywhere in the working progress; (2) The oil viscosity is not affected by the pressure; (3) All the components are absolute rigid body except the accumulator diaphragm; (4) The accumulator diaphragm’s mass is zero and it has no resistance in the state of deformation; (5) In most cases, the mass of oil is ignored and it can only be considered as lumped parameter when necessary; (6) The fuel delivery of oil pump is invariant when its delivery volume is constant; (7) The transfer time of pressure wave in the oil is ignored.

The influence of spray parameters on the particle in-flight properties and the properties of HVOF coating of WC-CoCr was examined by Zhao et a. [2].
The factors affecting the bond strength of high velocity oxy-fuel spray coating were studied by Wang et al. [3].
The influence of process parameters on molten particle speed and surface temperature and properties of HVOF coatings were investigated by Lib et al [4].
They indicated that stand-off distance, gun barrel length, and gas flow rate were the most influencing parameters on the coating wear properties.
The properties of HVOF NiAl nanostructured coatings were investigated by Hu et al. [6].

Fig. 1 Structure of a 600 MW Supercritical Boiler start-up separator Material properties.The metal materials used as boiler start-up separator of 600 MW supercritical unit are SA-336 F12, and some material properties are from the literature[5] by transfering units.
Table 1 Material properties of SA-336 F12 Temperature[oC] 20 100 200 300 400 500 600 Coefficient of linear expansion[10-6 oC-1] 9.7 10.7 11.8 12.8 13.5 14.0 14.4 Modulus of elasticity [105MPa] 2.09 2.03 1.97 1.89 1.82 1.74 1.65 Thermal conductivity [W/(m·oC)] 36.9 37.9 37.9 37.1 35.5 33.8 31.9 Density [t/m3] 7.83 Specific heat at constant pressure[kJ/(kg·oC)] 0.44 0.49 0.53 0.57 0.61 0.67 0.75 Model selection and network division.In the intersecting areas of start-up separator nozzles, the stress and stress-gradient are very high, and the stress concentration focus on the areas.
It studies the thermal stress, mechanical stress and the total stress.
Among them, the mechanical stress is the main factor.
(American Society of Mechanical Engineers, American 1998).

Experimental study Numerous factors influence welding quality indicators during RSW operations.
Fractional design cannot produce credible results when interactions among the factors exist.
With these limit values, three levels of setting were determined for each control factors.
The results revealed that it is possible to represent the evolution stages of the nugget formation and the most significant geometric features of the RD curve with a minimum of six points without significantly affecting the model performance.
Eagar: Measurement of dynamic electrical and mechanical properties of resistance spot welds, Welding Journal, 12 (1987) 66

Differences between the two beam designs (single vs. multiple web openings) can be significant in terms of distance between openings and structural performance due to other related factors.
The investigation of the said structural characteristics involved enlarging the web opening area ratio in the multi web openings and the steel tube’s width-thickness ratio (H/t), and using the web openings’ area ratio and location and the type of fiber that affect the structural performance as the main variables.
Mechanical properties of material To identify the properties of materials used in the manufacture of HPRWO, tensile strength testing was performed on the steel, and compressive strength testing on the concrete.
(2) In the case of providing the systems (web openings) at a location affected by the moments, it is expected that the yield strength of the HPRWO specimens will increase and the crack development be controlled as well
Park: A Study on the Structural Properties of RC Beams with Openings using Square Steel Tube According to Location and Area of Openings, Proceeding of Fall Annual Conference of the Architectural Institute of Korea (2010), p. 127-128 [5] S.

Temperature distribution and angular distortions obtained from the modeling closely matched with the experimental values.Zhengwei[ 5] studied the effect of the blow force of arc , heat transition in welding pool , heating radius of arc on temperature field and thermal cycle parameters in the SAW quasi-steady state by finite element model, the result showed that all factors mentioned above have great effect on temperature field but had little effect on weld thermal cycle.
Mathematical Formulation The temperature-dependent properties of Carbon-Manganese-Silicon steel SA738Gr.B was calculated by commercial software Jmatpro, the density and surface tension are plotted in Fig.1 and other physical properties are listed in Table 1 .
(a) Density (b) Surface tension Fig.1 Temperature-dependent properties of SA738Gr.B Table 1 Physical properties for SA738Gr.B used in this simulation.
As seen in Fig.3(a)-(d) the gravity, electromagnetic force, arc pressure, impact of droplets dramatically affect the weld transverse section, and shape the irregular weld pool surface profile.Weld cross-section is asymmetric and most partly of liquid heap up in the gravity direction, which is Y direction.
References [1] C.J.Bolton,P.J.E.Bischler and M.R.Wootton, Fracture toughness of weld metal samples removed from a decommissioned Magnox reactor pressure vessel, International Journal of Pressure Vessels and Piping,Vol.79(2002),685-692 [2] X.P.Zhang,L.Dorn, Investigation on the possibility of using the microshear test a surveillance method to estimate the mechanical properties and fracture toughness of nuclear pressure vessel steel,A508CL3,and its joints welded by narrow-gap submerged-arc welding, International Journal of Pressure Vessels and Piping,Vol76(1999),35-41 [3] S.P.Kumaresh Babu, S.Natarajan.

As shown in Fig.1,when the electromagnetic wave signal spreads in media, it will meets the interface with different dielectric properties and produces reflection, dispersion, attenuation and so on.
According to geological surveying data and tunnel construction, Karsts and developing Karsts water are revealed, and the volume of gushing water is greatly affected by these seasons.
(2) During excavation of the tunnel, there are overbreak and underbreak, and meanwhile tunnel supporting structure is not constructed in appropriate way and other unreasonable factors, as a result, there are some void areas between the lining and surrounding rock
Mechanical and construction of road construction machine, 2005, (10) : 8210
(in Chinese) [6] Qiunan Chen,Tunnel Engineering[M].Beijing:Mechanical industry publishing house,2007.8.

Many studies [1,2,5,7] have been published over the years for mechanical components, but by far, very limited information on the gear design and analysis has been revealed.
If the accuracy tolerance is acceptable, then we can claim that slope β is not affected by the loading conditions.
Thus, based on the test results, this function can be expressed by the following regressed equation: α=K1×R+K2 for the material properties tested
To further simplify and facilitate the life calculation process for different reversal loading condition (i.e. under different R-ratios), the normalization of the life degrading factor (DF) approach can be applied as shown by equation 15 Degrading Factor (DF)=α(at any R-ratio)/α1 (15) Applying equations 15, the following table (Table 4) show the relationships of the degrading factors (DF) under entire range of different R-ratios from uni-directional to fully reversal bending loads.
Dowling: Mean Stress Effects in Stress-Life and Strain-Life Fatigue, SAE 2004-01-2227 [2] AGMA 908-B89: Geometry Factors for Determining the pitting and Bending Strength of Involute Spur, Helical and Herringbone Gear teeth, AGMA Standard (1997) [3] ISO 6336-3: Calculation of Load Capacity of Spur and Helical Gears, ISO STD. (1996) [4] T.

The further development of PAEKs synthesis and properties, as well as creation of materials with new properties based thereon is still relevant.
All these factors were taken into account and used in various combinations in optimizing the preparation process of polyarylene ether ketones.
Structure and properties of heat resistant polymers.
Properties and application of special plastics.
Synthesis and properties.