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In the general atmosphere, the most important factor affecting concrete durability is chemical action.
（2）[2] Where: 𝑘𝑗 is the corner correction factor; 𝑘𝑐𝑜2 is the C02 concentration factor; 𝑘𝑝 is the casting surface correction factor; 𝑘𝑠 is working stress coefficient; T is temperature (℃{TTP}8451 ): RH is relative humidity (%).
The above two equations are both raised by Niu Di-Tao, on consideration of factors, (2) is more detailed and applicability better than (1).
Although fcuk is a mechanical indicator, and is not closely linked with the physical and chemical process of concrete carbonation, but the compressive strength is the comprehensive reflection of the water-cement ratio, admixtures, curing conditions, construction quality and other factors and easy to measure, therefore, it is an effective and practical method to predict the carbonation depth with fcuk
The mechanical properties of steel rust [1].

The combinations of materials have a significant influence on the sound absorption properties.
The two microphones transfer function method according to ISO 10534-2 standard was used to measure the materials sound absorption properties.
Seddeq (2009), Factors Influencing Acoustic Performance of Sound Absorptive Materials, Australian Journal of Basic and Applied Sciences, 3(4): 4610-4617
Umnova (2011), Acoustical Properties of Double Porosity Granular Materials, Journal of Acoustical Society of America, 130(5): 2765-2776
Swift (2001), The Effect of Consolidation on the Acoustic Properties of Loose Rubber Granulates, Applied Acoustics, 62(6): 665-690

Therefore a vertical additional force would be affected on the mine shaft liner and the vertical additional force would be the main factor to cause breakings on the mine shaft liner.
Mechanical potential erosion theory.
Mechanical erosion reduces the potential shear strength of the interface.
According to the change of rock property and structure, it can be divided into two sections.
Shaft in the operation period mainly is affected by the aquifer drainage.

Recent studies [1-4] have shown that metal matrix composite possesses better properties when compared to monolithic materials and its properties can be tailored according to the desired engineering application.
The particle size, volume/weight fraction and matrix alloy properties have a major influence on the wear characteristics of composites.
However, Purohit and Sagar [5] observed that reinforcement of more than 20 wt% have no significant improvement on the properties of the composites.
Results and Discussion Wear characteristics of MPS SiC aluminium matrix composite: The pin on disc tribo-system is widely used to study the wear properties of materials.
(a) Load: 24.5N Effect of variable speed and load on wear rate: The influence of varying speed and applied load are both considered as a major factor affecting wear rate.

Table 1 The characteristics of shaft in Cretaceous strata Serial number Name Unit Auxiliary shaft 1 Wellhead design elevation m 1385.5 2 Shaft depth m undecided 3 Shaft lining structure Double cast-in-place reinforced concrete 4 Freeze depth m 564 5 Net diameter m 10.1 6 Wall thickness m 1.65～1.95 The freezing pressure role in frozen wall is mainly affected by the deformation of the frozen wall,soil properties, formation depth,the frost heaving characteristics of thawed soil refreeze back of the wall,the temperature of frozen wall and the construction technology and other factors.
Conclusion The main factors affecting the freezing pressure of cretaceous strata is almost the same, that is mainly affected by the construction of dynamic load (blasting), stress release after rock excavation, frozen wall deformation, hydration heat of concrete and the iMPact of temperature beside the shaft, and gradually increased with depth.
The interaction between frozen wall and shaft is related to lithology, depth of layer and frost heave of the refreezing thawed soil, temperature beside the shaft, and construction technology and other factors.
Experimental research on the mechanical parameters of frozen pipes under low temperature [J].

And the split Hopkinson pressure bar (SHPB) has been widely used to determine the dynamic properties of these materials, such as metals, plastics, composites, concrete, and ceramics [1-5].
The stress states in specimen are affected by several factors, e.g., radial inertia effect, axial inertia effect and the friction constrain between the specimen and the pressure bars [11].
The mechanical properties of the bars are: E=200 GPa, ρ=7872 kg/m3.
The mechanical behaviors of specimen are the same as bar.

Introduction Cylinder is a die casting products, it exists many problems in production such as low yield, much defect and poor surface quality and so on, which will affect economic profitability and competitive capacity of enterprises seriously.
It improves the microstructure and mechanical properties and reduces the porosity and shrinks of the cast.
Fig.1 The casting 3D mould Fig.2 The finite element model In the process of die casting, there are many influence factors in liquid metal filling, the major ones being shot velocity, pressure, pouring temperature and preheated temperature of die.
Fig. 5 Cylinder production (a) position 1 in Fig.3 (b) position 2 in Fig.3 (c) position 3 in Fig.3 Fig. 6 Metallographic diagrams of three positions The microstructure and mechanical properties of the shell were observed.

Ahmed et al. (2007) studied how the compaction pressure affects the porosity of copper and showed the result that increasing of compaction pressure leads to decreasing on total porosity.
International Journal of Mechanical Sciences, (2008) 744-756 [2] D.
Mabuchi, Density dependence of the compressive properties of porous copper over a wide density range, Acta Materialia, (2007) 2291-2299
Processing and properties of highly porous 17-4PH stainless steel.
Shalabi, Correlation between factors controlling preparation of porous copper via sintering technique using experimental design.

The technique to asses and optimize the chosen factors to attain minimum surface roughness by integration response table and response graph, normal probability plot, interaction graphs, and analysis of variance (ANOVA) technique Palanikumar et al. [5].
They reported that, the material behaviour is not only inhomogeneous, but also dependent on fiber and matrix properties, and type of weave.
The material specification fiber, resin, TiO2 and mechanical properties of composites used in this work are given in Table 1 and Table 2.
The study of surface roughness characteristics of GFRP composites dependent on many factors, it is more influenced by the cutting parameters like cutting speed, feed, depth of cut, etc., for a given machine tool and work piece set-up.
The behavior of composites is heterogeneous and depends on the fiber and matrix properties, orientation of fibers, bond strength between fiber and matrix, and the type of weave.

The Discussion of Rotor Guide Channel Length of Vertical Shaft Impact Crushing Test Machine Wei Guo*,a, Fang Zhaob, Shijian Lic School of Mechanical Engineering, University of Jinan, Jinan250022, China agw420@126.com, bme_zhaof@ujn.edu.cn, clishijian_engineer@163.com Keywords: Testing machine; EDEM; Modeling and simulation; Rotor Abstract.
The result show that speed is important influence factors of granular acceleration and speed of throwing, but excessive speed will not only increase grain stress, but also can make particle fluctuations increased significantly, channel length and the starting position has a significantly influence on particle acceleration levels, the smaller of the channel’s initial distance, the better of the particle acceleration effect, particles thrown speed as the speed rises, the level of volatility is not always to rise.
In addition, its extensive work environment determines its acceleration process of particle has a certain ambiguity, for particle acceleration effect is good or bad will directly affect the production efficiency and product quality.
As a result, many crusher manufacturers and researchers study of particle acceleration effect given enough attention, they set off from the theory, the impact crushing properties of mineral particles were studied[2,3], aim is to understand the dynamic characteristics and predict impact angle and particle size on the result of impact, particle breakage is how to produce and broken form, determine the impact factors impact the results.
In order to improve particle acceleration effect and the rotor speed and other factors on the impact of speed thrown, thinning speed value, increasing 100,300,500,700 and 900r/min speed simulation.