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The Development of Modern Mechanical Design For half a century or longer, those factors that influence the endurance boundary of composite material on the one hand and performance limit of composite structure on the other have been the subject of a great number of analytical investigations, validated by precise measurement of critical property data.
Dimensions must be consistent with the overall function including minimum weight and there are data bases for materials properties to which designers can refer, (e.g., The Cambridge Materials Selector).
Why then, despite this vast acquisition of mechanical property data over a century or longer, our ability to fully understand that longstanding problem of fracture of structural materials remains restricted?
The "top-down method" of design, as it is sometimes called, begins with a macroscopic engineering model, a procedure that depends only on knowledge of straightforward macroscopically measurable properties, like hardness or yield stress, which an engineer can handle.
This provides us with scope for optimisation, where composite material properties vary continuously with some internal parameter that relates to composite architecture in some way.

Materials and Methods Straightness of rails is one of the main indicators of their quality, affecting the stability and throughput of the railway.
Considering this issue, it is proposed to distinguish 6 main groups of parameters and factors, 2 groups of which characterize the entire cycle and the existing level of production of rails before their editing, and the remaining 4 groups of parameters refer directly to the correction of rails.
Factors affecting the straightness of finished rails: - statistical dispersion of straightness of rails before straightening; - statistical dispersion of values of mechanical properties, height and other geometric dimensions of the cross-section of rails before straightening; - main unchangeable parameters of rail equipment; - characteristics of the applied straightening technology; - parameters of machinery and technological equipment, which affect the stability of maintaining the technological mode of straightening; - automation of straightening process and control of straightness of finished rails.
On each individual rail, we will get different values of residual stress, different straightness and a general deflection, since before correcting for rail indicators, many factors, such as: 1.
All these factors have a direct effect on the straightness of the rails.

This Paper designs a mechanical device for the manipulator of the watermelon picking machine against the low mechanical degree of watermelon picking machine.
Design of the Mechanical Device of the Manipulator Design Principle.
According to the cylindrical supporting bar under the stress of 175.4N, the displacement constraint, material property, and stress, etc[4]. of the cylindrical supporting bar are set with Pro/E, the static analysis of the cylindrical supporting bar is newly conducted, and the analysis result is finally obtained from the result definition window.
The correction factor is selected to be k=1.1 and the pressure here is calculated to be F=(6/0.319/1.1)N=17.09N with the influence of the frictional force of influence.
What's more, the accuracy of spare parts processed according to related drawings meets requirements, the assembly accuracy of the shearing mechanism may affect the performance to some extent, and the its stability shall be yet to be improved.

The chemical composition and mechanical properties are shown in Table 1 and Table 2 separately.
Table 1 Chemical composition of the 35CrMo steel (Wt.%) C Cr Mo Mn Si P S 0.32-0.40 0.80-1.10 0.15-0.25 0.40-0.70 0.17-0.37 ≤0.035 ≤0.04 Table 2 Mechanical properties of the 35CrMo steel Tensile strength σb(MPa) 0.2%Yield strength σs(MPa) Elongation δ(%) Reduction of cross-section ψ(%) Hardness HB ≥980 ≥835 ≥12 ≥45 ≤229 The specimens were machined into cylinder with a 10mm in diameter and a 15mm in height, which surface was wet ground steeply with SiC paper followed by 360#, 600#, 800# and 1200#, until the surface is smooth and bright to the standards of experiments.
In the conditions of hydro-blasting perforation, many factors affect erosion performance of the material, for example: the flow rate, spray angle, erosion time, etc.
EXPERIMENTAL RESULTS AND ANALYSIS In the conditions of hydro-blasting perforation, many factors affect erosion performance of the material, for example: the flow rate, spray angle, erosion time, etc.
CONCLUSIONS The erosion effect of the solid-liquid mixed solution on 35CrMo steel is mainly reflecting as mechanical erosion wear, which contains 0.2% hydroxypropyl guar gum solution mixing quarts sand.

The rate of loading is a main sensitive parameter that affects both damage initiation and propagation, as they increased significantly with increasing loading rate.
Introduction Real life structural materials are exposed to different types of loadings leading to material deterioration and change in their structural/mechanical properties.
This progressive physical process of degradation in the mechanical properties with complete loss of stress carrying capacity is commonly referred to as damage.
Mechanical properties were obtained from the uniaxial tensile tests of steel, as shown in Fig. 2, and the hardening behavior was mimicked using Johnson cook model (See Eq. 3).
Results are compared and discussed in terms of the effect of loading rate on the damage level Fig. 4 Views of the neck section with contours showing equivalent plastic strain and mises stresses Effect of Strain Rate on Damage Briefly, the deformation of materials under load depends on factors, such as atomic structure, rate of loading, and temperature.

Recently, ternary Cr-X-N coatings, where X is one of the various alloying elements such as Ti, Si, Al, Ta, Nb, Ni, B and C, have been explored in order to further improve the various properties of CrN coatings [1].
Hardness is one of the most important material properties affecting resistance to wear.
Surface material properties for tribological applications can be described in terms of their measured hardness and elastic modulus (E) [6].
Factors Hardness (GPa) Types of Coatings 1 2 3 4 5 CrN 13.7606 14.9175 15.3766 11.5564 7.3052 CrC 5.8264 5.6372 5.3694 6.0361 5.6284 CrCN 12.9159 11.5862 9.4741 11.3593 12.1628 In this investigation, the factor that determined the observed hardness was the types of coatings that had been previously applied to the upper hooks.
Note that the coefficient of determination (R2) provided the proportion of the total variation in the response variable and it is explained by using the process factors that included in the model [7].

Influence of creep model on glass tempering process Peize Zhong1, a, Lizhong Wang2,b, Quanwei Liu3,c and Wanxiao Sun4,d 1234Xi'an Jiao Tong University, School of Mechanical Engineering, Xi'an, China apeizezhong@gmail.com,bwanglz@mail.xjtu.edu.cn cliuquanwei8@gmail.com,dsunwanxiao@stu.xjtu.edu.cn Keywords: creep model; glass tempering; equivalent specific heat method; residual stress Abstract.
Figure 3 Creeping property Usually, temperature T, stressand structure factor S are considered to be the three independent variables which affect the creep rate, that is [3]:
(1) The structure factor S means the factor of affecting the creep rate in material internal structure.
Rheological properties of Y-Si-Al-O-N glasses-elastic moduli，viscosity and creep[J].

Introduction The copper–based precipitation alloys Cu–Fe, Cu–Co and their ternary have been previously studied in terms of their mechanical properties and precipitation processes [1-6].
Thus, the present study aimed to investigate in detail how precipitate microstructure is correlated to magnetic properties in a Cu–Ni–Co nanogranular magnetic material.
Experimental We investigated the details of the precipitation phenomena and magnetic properties of a bulk Cu–10 at% Ni–5 at% Co alloy.
Fig.6 M–H hysteresis loops of the Cu–10 at% Ni–5 at% Co alloy isothermally aged at 1023 K Magnetic Properties of Cu–Ni–Co Specimens Containing Nanoscale Granular Magnetic Particles.
Thus, the annealing temperature was an important factor affecting the microstructure and magnetic properties.

But in the design of interface, the assumption is made that the shear is uniformly undertaken by shear stubs, neglecting the chemical cementation force, mechanical joining-up stress and effect of contract friction.
This assumption is uninfluential to the whole performance of the bridge, but has a major impact on the arrangement of shear stubs which is affected by the friction on the interface and the shear distribution of shear stubs in their group.
To study how friction on the interface affects the property of the joining section, three models are made in this paper.
Fig.7 Shear of stubs in middle column Fig.8 Shear of stubs in edge column Fig.7 and Fig.8 show the shear distribution of the stubs is identical in three models to the steel-concrete interface, and the stress of model 2 and 3 is a little smaller than the model 1 in which contract is neglected Conclusions The chemical cementation force and mechanical joining-up stress were not taken into account in this paper, because of the capability of FE soft and complex affected factors which are hard to determine without sufficient experimental data.
The consideration of contract to steel-concrete interface is negligible to Mechanical Behavior of steel and concrete box girder in the bridge. 4.

Blends will be endowed with the better properties from original components, such as mechanical properties and hydrophilic character, etc.
To compare the mechanical properties of NR and modified NR films, mechanical properties tests were operated according to GB7543-2006.
Good dispersion of the filler particles is a crucial factor to obtain admirable mechanical properties [29].
Mechanical properties and elongation at break of NR films modified by PMMA, PMMA-CPL and PMMA-CPL-SS.
Rheological, mechanical and morphological properties of thermoplastic vulcanizates based on NR-g-PMMA/PMMA blends, J.