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At present, the quality of resistance spot welded joints is mainly determined through a test of its mechanical properties.
Therefore, it has important engineering significance to comprehensively study the impact of different welding parameters on mechanical properties of resistance spot welded DP steel joints, find the optimal welding parameters, determine the most intuitive control factors of the mechanical properties, establish quality evaluation model.
Sun et al[11] (2007) studied the corresponding relationship between metallographic structure, mechanical properties and welding parameters of the 1.2 mm thick magnesium alloy resistance spot welded joints.
In fact, welding parameters includes welding current, welding time, welding pressure, welding environment, cooling environment, etc., each parameter change will affect the mechanical properties of joints, it is not limited to current changes, and current changes is not the only or direct cause of nugget change.
The researches mainly focused on effects of welding parameters on nugget size, mechanical properties (tensile-shear load, failure energy, failure modes, fatigue, etc.) and microscopic characteristics (structure, microstructure, micro hardness) of joints, and identifying the control factors of resistance spot welded joints.

Stiffness, carrying efficiency and fatigue are the important properties of the end anchor cable.
The influence of the end anchor cable stiffness on the mechanical properties of cable-stayed bridges.When the known expression (1) is substituted to the expression , expression (3) is obtained
Comparison of mechanical properties between CFRP and steel is showed in table 1.
The important factors on the fatigue property of the end anchor cable are detailed analyzed finally.
The side span la,main span lm,pylon height h,area of the end anchor cable A and collection degree q of live load are the important factors on the fatigue property of the end anchor cable.

Results and Discussion Discussion on influencing factors of synthetic reaction The effects of various factors on the experimental results were investigated by orthogonal experiment.
The greater the extreme difference R, the greater the influence of its factors on the experiment.
Therefore, the ratio of reactants is the main factor affecting the experimental results, while the reaction time is not.
It shows that the main factors affecting the experimental yield are reactant ratio and reaction temperature.
[3] Liang, B.; Wang, G.; Hong, X.; Long, J.; Tsubaki, N., Synthesis and properties of a new halogen-free flame-retardant epoxy resin curing agent.

However, several vital issues, such as the structure-properties relationship of aggregation-induced emission (AIE), still remain unclear, which impede the discovery of novel piezochromic luminescent materials with excellent properties.
Because the interaction plays a key role on luminescence properties, resulting in a little red shift because of excimer emission formation[10].
Therefore, Li et al. selected 2-(anthracen-9-yl)-4,5-diphenyl- 1H-imidazole (ADPI) as the model polymer, which showed a clearer relation of molecular packing and luminescent properties.
Many attempts were made for better understanding of their molecular stacking and luminescence properties, and people found that π-π interaction as well as hydrogen bonds are two principal factors affecting the emission wavelength; however, the deeper mechanism and physics are still need to be explored in the future as the guidance of discovering novel AIE materials.
Supramolecular Structures and Assembly and Luminescent Properties of Quinacridone Derivatives.

The pressure field, the velocity field, the particle tracking, the turbulence kinetic energy distribution and the flow field vorticity distribution of the seal cavity flow field were obtained by solving the three-dimensional N-S equation; and then the seal cavity medium temperature distribution was get by solving the energy equation, so the influencing factors that the flow and the heat transfer of the flow field make the temperature of the friction pair surface rising were analyzed, and the main factors affecting the temperature was found out.
In fact, the heat transfer of the fluid in the seal cavity is closely related to the fluid flow, the flow pattern, the velocity, the pressure and the temperature of the fluid directly affects to the temperature field of the friction pair.
Therefore, it is necessary to study the seal cavity flow field and the temperature field of the friction pair as a whole, simulate the fluid flow pattern, analysis the nfluencing law of the fluid dynamics properties to the temperature field of the friction pair, and find out the effective measures to control the temperature of the sealing rings of the friction pair.
The thermal oil pump belows mechanical seal is used as the researching object, and the of the seal cavity flow field was established, shown in Fig.1.
The physical properties of the specific medium and boundary conditions for the numerical computation is shown in Table.1., and the controling equations for numerical computation was select by using the PRESTO as pressure difference scheme.

The gears of a gear box were modeled and analyzed through Romax, and the effects of pressure angle on their lubrication properties were studied.
The lubrication condition of the tooth surface was an important factor that affected the performance and the bearing capacity of the gear transmission.
The safety factor increased 49% when the pressure angle increased from 20° to 25°.
The pressure viscosity property was considered by the Dawson Higginson formula, and the viscosity pressure coefficient index was 0.6 in the formula.
And the rolling velocity mainly affected the distribution of oil film thickness.

FATIGUE CRACK GROWTH BEHAVIOR OF A GAS PRESSURE WELDED PART OF RAIL STEEL UNDER MIXED MODE LOADING Chul-Su Kim 1,a and Jung-Kyu Kim 2,b 1 Department of Rolling Stocks Mechanical Engineering, Korea National Railroad College, Wolam -Dong, Uiwang-Si, Gyeonggi-Do, 437-763, Korea 2 School of Mechanical Engineering, Hanyang University, Seoul, 133-791, Korea a chalskim@paran.com, bkimj@hanyang.ac.kr Keywords: Comparative Stress Intensity Factor Range, Gas Pressure Welded Part, Rail Steel, Mixed Mode Loading, Transverse Crack Abstract.
In this study, the fatigue crack growth behavior under the mixed mode was discussed by using comparative stress intensity factor ranges proposed by Richard.
The mechanical properties of the base metal and the welded part of rail steel were summarized in Table 1.
Table 1 Mechanical properties Yield strength (MPa) Tensile strength (MPa) Elong ation (%) Fracture toughness CK (MPa) Base metal 481 887 14.5 46.6 Welded part 545 936 9.65 43.3 Heat affected zone SLT SLT Heat affected zone Fig. 1 Position and orientation of test specimens The FCG test using the CT specimen under mode I (tensile mode) was performed at different stress ratios R according to ASTM E647-95a.
max max min eff op V V V V V V K K K U K K K ∆ − = = ∆ − (1) where max VK and min VK are maximum and minimum comparative stress intensity factors, respectively, and op VK denotes comparative stress intensity factor which is calculated from the Pop.

Some influencing factors on damage will be discussed within the framework of continuum damage Mechanics(CDM).
The innercasing is made of GX12CrMoWVNbN alloy steel and its material properties are listed in Tab.1.
Mechanical properties and damage evolution parameters Mechanical properties of the innercasing Damage evolution parameters Temperature(℃) 100 200 300 400 500 600 Temperature(℃) 540 565 600 Conductivity (W/m K) 38.9 38.1 33.9 33.1 30.1 26.4 B(1030) 59.980 3.169 0.176 Specific heat(J/kg℃) 487.4 507.6 565.2 622.8 669.6 716.4 n 11.737 11.557 11.357 Expansion(10-6/℃) 11.49 12.03 12.43 12.80 13.23 13.32 σUTS(MPa) 555 530 500 Density(kg/m3) 7800 7780 7750 7720 7690 7660 α 11.24 Elastic modulus(109Pa) 215 205 198 189 181 168 U(KJ/mol.K) 380.8 Poisson’s ratio 0.281 0.281 0.284 0.294 0.275 0.298 Besides, the stresses in the innercasing are mainly induced by the uneven temperature distribution and the steam pressure differential during the turbine operation.
The main influencing factors on Damage.
Degradation of mechanical properties of cast Cr-Mo-V and Cr-W-V steam turbine casing after long-term service at elevated temperatures[J], Part I: tensile properties, brittle fracture strength and Charpy impact properties, Int.

Introduction Analyzing plastic deformation and failure processes of metal materials, the following factors are usually discussed: material structure, deformation velocity, temperature, etc.
However, the impact of surface layers on deformation process is taken into account very seldom, though they very often influence the mechanical properties, mechanisms of plastic deformation and failure [1-3].
This is beneficial from technological as well as economical point of view since a cheaper metal is used, whereas mechanical properties remain good [2].
Fatigue resistance is one of the most important mechanical properties.
The fractures of the samples have such specific properties.

The test result show that there are some correlations and trends between uniaxial compressive strength and point load strength, the shape size and lithology of rock specimens have important influence on the result of point load test, and the greain size, the mineral compositon and the structral compact are key factors.
Introduction The mechanical strength of rock is an important parameter for rock engineering designing, constructioning, its accuracy directly affects the security and stability of the construction and operation,As well as the economic rationality of construction[1-5].
By eye’ discerning, engineering geological properties of the rock sample is divided into roughly the same group.
From figure 2, although the rock sample homogeneous andregular shape were tested, but the related law of point load strength and saturatedcompressive strength is still not clear, the property of rock itself Plays a decisive role,the corresponding regression equation list: Rc = 18.68Is（50）+ 23.3 R2 = 0.6579 （7） Rc = 22.39Is（50） R2 = 0.6229 （8） Rc = 23.96 Is（50）0.9671 R2 = 0.6633 （9） From the fitting formula obtained by the above,we can find that the correlation coefficient of regression is not high, the quantitative description of Rc and Is (50) relationship is not precise enough.
But the shape and dimensions of the sample, lithology and structure factors directly affect the Rc and Is (50) the relationship, in which the particle size of the rock, mineral composition, the degree of its dense structure factors play a more dominant influence.