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The study of contact characteristics of ball screw will provide theoretical bases for improving transmission efficiency and working properties of ball screw.
(19) From the Eq. 19, it is deduced that the axial contact stiffness of ball screw is affected by factors such as load, design parameters and manufactured material properties, etc.
It could provide theoretical basis for optimal structure design of ball screw via analysis of these influencing factors.
In order to satisfy demand of actual utility, it is necessary to comprehensively consider the influence of material properties.
Zhang: China Mechanical Engineering Vol. 19 (2008), p. 1079-1083

It was established that the surface quality was significantly affected by a new factor – angle of indenter contact with the machined surface, which had a damping effect on the machine-fixture-tool-workpiece system.
Construction of simplex S3 from simplex S0 in the problem with two factors Thus, the essence of simplex experimental design can be expressed by the three simple rules: 1.
It is necessary to range the factors in order to adjust their controllability. 4.
Guryanova, Mechanical properties of steel and alloys subjected to plastic deformation.
Journal of Mechanical Engineering Science. 9 (1967)

It is known that a large number of factors influence the formation of adhesive contact and the most important of them are the processes of a consistent adhesive distribution on the surface of the substrate with the formation of chemical bonds, mechanical adhesions, local stresses and defects at the phase boundary.
For injection composites based on CF treated with graphene, an increase in mechanical properties of 20 % appears compared to untreated ones.
The structure and arrangement of the fiber in the matrix plays a crucial role in regulating the mechanical properties.
Carbon fiber fabric reinforced PPS laminates: Influence of temperature on mechanical properties and behavior, Adv.
Taleb, Carbon fiber fabric reinforced PPS laminates: Influence of temperature on mechanical properties and behavior, Polym.

Hood is an important part of the automobile, which directly affects the vehicle performance.
Connecting mode between sheet metals mainly used CWELD unit and RBE2 unit for simulating, the glue between inside and outside plate was simulated by RBE3[3].The hood’s quality is about 17.22kg, its properties are shown in Table 1: The hood assembly’s finite element model was shown in Fig.1 below: Table 1 Model's material and properties Material E(Mpa) μ ρ(t/mm3) Steel 2.10×105 0.3 7.8×10-9 Glue 14 0.35 1.1×10-9 Fig.1 The hood's finite element model Analysis of constrained mode.
If stiffness is insufficient, excessive deformation appears to closures’ local area, which affects the safety, sealing, thus affects the normal use of the vehicle [5].
Design variable S1 and S6~S8’s first order natural frequency sensitivity magnitude is 1 order natural frequency sensitivity, explain that they are the main factors influencing the hood assembly’s model frequency, meanwhile design variable S1 to S3 and S7 is the main factors influencing the bending stiffness; And design variable S1 ~ S7 has certain influence on torsional rigidity sensitivity, As far as lateral stiffness sensitivity design variables except S2, S3 have played a leading role in performance.
[6] Liu Linhua, Xin Yong: Based on sensitivity analysis of truck frame lightweight study [J], Journal of mechanical science and technology, 2011, 30 (10), p.1724-1727

Fatigue Properties of a T Type Welded Joint in a Small-sized Single Pass Boiler Header H.Yamakawa1, a, N.Yan 2, b, D.Yonekura 2 and R.Murakami2 1 Miura Co., Ltd., Japan 2 Dept. of Mech.
Chemical composition and mechanical properties of SS400 are shown in Table 1.
Table 1 Chemical composition and tesile properties of SS400.
It is clear that the weld penetration markedly affect the fatigue strength.
The stress concentration factor, Kt, at the toe of weldment was calculated from FEA results.

Ceramic particles show larger mechanical properties to unreinforced Al as matrix.
RHA addition results in healthier mechanical properties [5,6].
It is found that when developing Al- RHA (3,6 & 9 wt. %) MMC with 1% Mg as wetting agent by stir casting, its improves mechanical properties.
Srinivasa Rao, Effect of Rice Husk ash and Fly ash Reinforcements on Microstructure and Mechanical properties of Aluminium alloy (AlSi10Mg) Matrix Composites, Int.
Krishna, Production and Mechanical Properties of A356.2 /RHA Composites, Int.

This is one of the most successful and reliable methods to produce near net shape products exhibiting good mechanical properties.
Production of feed stock with non-dendritic and spherical structure is the critical factors in semisolid forming.
So the distances between α-Al rich phase and eutectic became smaller and thus it can affect on diffusion during reheating process.
The soaking time and temperature in semi- solid state are two important factors to control the grain growth and degree of globularity.
This factor is distance for diffusion.

Introduction The increasing use of aluminium alloys in the manufacturing of automotive parts has pushed car manufacturer to look for new processes to obtain better technological performances than the traditional castings (which usually imply defects, dendritic microstructure and poor mechanical properties) [1] and higher flexibility and lower costs compared to forging [2].
In case of axi-symmetric parts, flowforming has become an attractive solution, since the high localization of the strains allows significant reduction of the loads applied on the tooling, high mechanical properties of the deformed part, and excellent wall thickness distribution [3].At present the knowledge of this process mechanics still shows several gaps and standardized procedures aimed to the process design have not been developed yet, except for specific casesthat can be hardly widespread in industrial world, in which the choice of optimal process parameters remains an “art”[4].
This work is the follow-up of two previous studies on the same topic: in the first one [13] an analytical model for the roll-part contact area was proposed, while in the second one [14] the influence of heat treatment on microstructure and mechanical properties was experimentally investigated.
Gleeble 3800™ thermo-mechanical simulator was used to perform the hot compression tests suitable investigate the material mechanical characteristics.
On the other hand, the rotation speed n and the feed rate f can be considered as second-order factors, for a given fr value.

The influence of designing factors on product will be restrained in an allowable range by adjusting the design variant and its tolerance properly.
In terms of detailed design information of evaluating objects and confirmed evaluating targets, taking into consideration of uncertainties on evaluation information, the fluctuation of mass properties membership degree is used to indicate the fluctuation of design proposal, and thus may get a design proposal with better robustness.
The process of tolerance design is to choose the most suitable tolerance for each parameter, i.e. considering the influence of parameter fluctuation on the mass properties, discussing whether to adjust the tolerance of some parameters or not from the economic point of view.
Fig.2 Functional module of designing and analyzing phase Applications The controllable factors of helical gear: helical angle β, normal module mn, tooth width:b, The design variable will be:
(5) Where W1,W2 are weight factors, their values depend on the quantity and significance level of two separate target functions.

The influence of contact states on dynamic properties of combination samples is analyzed based on the dynamic stress-strain curves and accumulative strain curves.
The practice indicates that the contact state between the bedrock and the concrete of the bottom structure is one of the critical factors which affect the service performance of the tunnel bottom structure.
Their major physical and mechanical properties are listed in Table 1.
On the premise of keeping the original properties of the rock samples, which were cut into two different types of cylindrical specimens with 15×15 cm and 15×12.5 cm (diameter×height) respectively.
Y., etal.: Experimental Research on Dynamic Properties of Coalmining Wastes.