Search results

The Effects of Different Defects on Vibration Properties of Single-walled Carbon Nanotubes Lijie Chen1,a, Qi Zhao1,b and Zunqun Gong1,c 1School of Physics and Mechanical & Electrical Engineering, Xiamen University, Xiamen 361005, China achenlijie@xmu.edu.cn, bzhaoqi19850827@163.com, cgzqhnn@163.com Keywords: Single-walled carbon nanotubes; Atom vacancy defects; Stone-Wales defects; Vibration properties; Finite element method Abstract.
The computational results show that the length, the diameter and the defect position of SWCNTs are three important factors affecting the vibration properties of SWCNTs.
Introduction Ever since the discovery of carbon nanotubes (CNTs) in 1991 [1], more and more studies are focused on their excellent mechanical properties.
Due to the restrictions of manufacturing, different defects, such as atom vacancy and Stone-Wales defects, exist inevitably in the CNTs, which affect their mechanical behaviors.
The wall thickness is 0.34 nm and the material properties are referred to [8].

Studying Mechanical Properties Specially Fatigue Behavior of (Polyether Ether Ketone)/Glass Fiber Composites in Aerospace Applications Prof.
Abstract: This work deals with studying the mechanical properties specially fatigue behavior for high performance composite materials of poly ether ether ketone (PEEK)/glass fiber, which are used in Aircraft Industry.
The tests show inhomogeneous results, so it is necessary to do many repetitions to get a more accurate estimate of fatigue life. [6[ Composite materials behavior subjected to fatigue load is very complex due to non-homogeneous and anisotropic properties, and it has been studied for a long time; however, composite materials design is still based on very long fatigue tests and high safety factors are used.
S-N curves of the composites generally depend on several factors]6, 11, 12 [: • Material and fiber volume fraction (Vf); • Matrix (resin); • Guidance plan; • Test variables: • Load type; • Average stress; • Frequency; • Environmental conditions.
Oğuzhan Yılmaz, Fatigue Properties Of Materials, http://www.gantep.edu.tr/~oyilmaz [13].

Fig. 3 Failure probability change for distribution parameters of mechanical properties (a) Yield strength (b) Fracture toughness.
The sensitivity factors of fracture toughness are very small.
Fig. 6 shows the influence of mechanical properties distributions on failure probability.
The weibull distribution of both yield strength and fracture toughness has the lowest Pf values when the mean value of mechanical properties is low.
Fig. 6 Failure probability change for different distributions of mechanical properties (a) Yield strength (b) Fracture toughness.

These phases are known to degrade the mechanical and corrosion properties of the weld metal [4].
However, the formation of these phases is influenced by a number of factors such as weld metal composition, ferrite content and its morphology, in addition to temperature and time of transformation [4].
The mechanical properties of δ-ferrite containing weld metals are generally controlled by the kinetics of δ-ferrite dissolution, as well as the nature of transformation products [7].
Therefore, transformation kinetics and its subsequent effects on mechanical properties has been the subject of many studies [5-8].
Tensile Properties.

Experimental Study of Biological Material Preparation Based on Optical and Mechanical Dynamics Junmei Wan1, a, Mingzhang Ao2 1Biological Engineering College, Wuhan Polytechnic, 430074, Wuhan, China 2School of Life Science and Technology, Huazhong University of Science and Technology, 430074, Wuhan, China a e-mail: junmei_wan@163.com Keywords: Electrochemical; Mechanical dynamics; Optical properties; Nanometer material; Tissue engineering; Implantable medical devices Abstract.
The main components of Konjac glucomannan are glucose and glucomannan that are byβ1-4 bond [ molar ratio is 1.6: (1~4) ] of high molecular weight non-ionic glucomannan, special glucose and mannose’s β -1-4chain structure isn’t affected by the human digestive enzymes, and does not generate heat.
According to the peculiar properties of konjac glucomannan, through the scientific experiment in the body of a rabbit to verify its unique immunological function, and then the human experiments after the effective experimental data statistics scientific analysis, finally the system can obtain the effect of konjac glucomannan on human immune system.
Purification and properties of konjac-oligosaccharidos [J].
[7] Xu Shiying, Qian He. konjac-oligosaccharidos chemical structure and rheological properties [J].

It gives more particularly decrease factors for the ultimate tensile strength, the characteristic yield stress and the elastic modulus with temperature up to 1200 °C.
The average results and the standard deviation are given in Table 1 for each studied case and for the three mechanical properties: ultimate tensile strength Rm, characteristic yield stress Rp0.2 and the elastic tensile modulus E (determined accordingly with [2]).
Obtained experimental mechanical properties for steel rebars Maximum temperature, in °C d, in mm Rm, in MPa Rp0.2, in MPa E, in GPa 20 12 590.5 +/- 0.9 535.0 +/- 3.4 195.5 +/- 5.7 40 12 587.6 +/- 3.8 534.5 +/- 3.6 211.5 +/- 20.7 100 12 572.2 +/- 0.7 518.1 +/- 1.6 229.8 +/- 9.8 140 12 573.1 +/- 0.5 518.2 +/- 2.3 217.1 +/- 21 20 16 573.2 +/- 0.7 504.5 +/- 2.0 197.4 +/- 8.7 140 16 551.7 +/- 2.9 482.5 +/- 6.2 191.4 +/- 6.0 Experimental investigations on the adherence between concrete and rebars State-of-the art.
It gives more particularly decrease factors for the ultimate tensile strength, the characteristic tensile stress and the elastic modulus with temperature up to 1200 °C.
Obtained experimental mechanical properties for prestressing wires Maximum temperature, in °C Rm, in MPa Rp0.1, in MPa E, in GPa 20 2110 +/- 12 1867 +/- 3 226.1 +/- 5.0 40 2095 +/- 11 1854 +/- 15 226.3 +/- 0.9 100 2048 +/- 3 1793 +/- 4 224.5 +/- 3.4 140 2015 +/- 15 1726 +/- 14 213.4 +/- 1.1 Experimental investigations on the relaxation of prestressing steel wires State-of-the art.

Influence Factors Analysis of CFG Piles Treatment.
By analyzing pile length, modulus and spacing of CFG piles composite foundations, we can find that highway soft ground subgrade settlements are affected by the following influence factors. 1.
The modulus of CFG pile, which is determined by the material properties of cement, fly ash and gravels, should be designed in the range of optimum values. 3.
Space between piles is the most significant influence factors of settlement control in CFG piles composite foundations.
In summary, pile spacing affects most among the influence factors in settlement control treated by CFG pile composite foundation.

Rock deformation and support pressure depend not only on the in-situ stress and rock properties, but also on the other factors, as the own attributes of support and mounting arrangements.
The mechanical properties of soft rock engineering depend on the clay mineral composed of soft rock.
The clay minerals are the main factors to affect the mechanical properties of soft rock while the variability of the clay mineral content is one of the factors leading to the variability of the physical and mechanical properties of soft rock.
Due to the critical load and the critical depth of softening are closely related to depth, density and layer thickness of rock, there also exists randomness in softening critical depth.Factors affecting the stability of surrounding rock of underground soft rock engineering are greater randomness and uncertainty than the general rock engineering.
The balance of the tunnel depends on the physical and mechanical properties of surrounding rock and the size of initial stress.

Therefore it is significant for the understanding of the tensile performance of the woven membrane materials, which is a main factor for the evaluation of the mechanical properties of the materials.
However, in this method, due to the existence of the sewn yarns, the tensile properties of the membrane materials obtained have been affected significantly.
Factors in the cruciform-shape bi-axial tensile tests Although the cruciform-shape bi-axial tensile tests have been applied mostly, there is no international standard about that.
Due to the inelastic property and the long expected service time of the flexible membrane materials, it is necessary to grasp the mechanical property after the application of the materials on the light weight structure for a long time.
The factors, such as the configurations and dimensions of the cruciform sample, the loading modes of the bi-axial stresses and the means for the measuring of the strains, which would affect the mechanical properties have been analyzed in detail.

Fairly complete review of different works dedicated to the influence of optical fibers on mechanical properties of polymeric composite materials, its usage from mechanical point of view, measuring of strains with the help of fiber Bragg gratings is given in [8].
Modeling of integral mechanical properties Multilayered plate of length l = 125 mm, width s = 45 mm, made from GFRP VPS-33 with glass fiber filler T-10-14 and epoxy matrix ENFB-2M is considered.
The values of effective elastic properties of composite material and mechanical properties of optical fiber are presented in Table 1.
One of the crucial factors affecting the integral characteristics is orientation of optical fibers under the action of external load.
[3] Roberts S.S.J., Davidson R., Mechanical Properties of Composite Materials Containing Embedded Fibre Optic Sensors, SPIE Fiber Optic Smart Structures and Skins. 4 (1991) 326-341