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China Journal of Highway. 2000, 13 (4) : 74 ~ 78(In Chinese) [4] LiuZhao, Meng Shaoping, etc.
Journal of Chang'an University (Natural Science Edition). 2007, 27 (3) : 47 ~ 51(In Chinese) [6] DiJin, Zhou Xuhong.
China Journal of Highway and Transport. 2007, 20 (4) : 48 ~ 52 [7] Li Yue, Zhu Hongping.
Journal of Guangzhou University (Natural Science Edition), 2002, 1 (3) :79 ~ 83(In Chinese) [9] YanHai, Fan Lichu.
China journal of Highway and Transport, 2004, 17 (2) : 46 ~ 49(In Chinese) [10] Wang Xinmin.

Williams [2] proposed a two-parameter approach for the isotropic linear elastic materials.
On the other hand, out-of-plane crack tip constraint is also known to have a significant influen- ce on the fracture behavior of materials, and work have been done to express this constraint along the 3D crack front by the out-of-plane -stress [1].
That is, the singularity as described in Eq. (1) occurs only near crack front points embedded entirely in material.
Acknowledgments This paper was supported by National Natural Science Foundation of China and by the 111 Project Nos.
Vol. 29 (1992), p.1597-1611 [14] Junhua Zhao, Wanlin Guo: International Journal of Fatigue.

Introduction At the present time, the metal bar is a common-used structural material in the manufacturing industry, and is widely used to make into various parts, such as gears, shafts, flanges, chain pins and so on.
High-quality cross-sections are obtained from different materials, which prove that the cropping method by means of the radial forging in precision cropping is feasible.
Acknowledgements The author wishes to express gratitude to the National Science and Technology Major Project (Approval No.2009ZX0414-074), the Hi-tech Research and Development Program of China(Approval No.2007AA04Z144) .
References [1] Chen JD, Wang YW, Yu DH, Zhang ZG (1992), Brittle Precision Cropping of Metal Materials.
Journal of Xi’An jiao Tong University. 2004, 38 (9): 947-950

Although the maximum working stress is less than the ultimate strength of the material, stress concentration in the area of local caused small micro crack initiation, with an increasing number of cycles, micro crack expanded gradually, finally to transient faults.
Maximum stress value of the piston rod with rounded corners was still less than the ultimate strength of materials, but the stress concentration at the fillet resulted in the fracture of rods.
Nonlinear finite element analysis of the piston rod under the impact load. edtied by Applied Mechanics and Materials(2013)
Nonlinear finite element analysis of the mechanical properties of the leaf spring. edtied by Mechanical Science and Technology (2008),
Mechanical properties of finite element analysis of concrete filled square steel. edtied by Journal of Wuhan University(2004)

Introduction With the continuous progress of science and technology, and with the continuous development of manufacturing industries, accuracy and surface quality of the mechanical parts are required increasingly high; various high hardness materials are used increasingly.
Workpiece mounting 2.3 The Main Technical Parameters (1) Grinding diameter: 50mm; (2) Grinding length: 120mm; (3) The diameter and width of grinding wheel are 400mm and 150mm respectively; (4) The diameter and width of guide wheel are 300mm and 150mm respectively; (5) The Vertical rotation angle of guide wheel: -～; (6) The speeds of guide wheel at work and amendments are 20~100r/min and 200r/min respectively; The speed of grinding Wheel: 1668r/min; (7) Dimensions of machine tool/ mm (L × W × H): 1920 × 1680 × 1868; (8) Centerless cylindrical grinding machine in this design can be used to process optical axis, the stepped shaft with shaft shoulder; precision IT7 the following; Ra1.6 ~ Ra0.4; materials: 45, 40 cr, ductile iron, and so on.
(2) Belt material: polyurethane
Journal of Ezhou University.2010,17(2):24-28

Adding Material and Movement.We determined the model material according to the actual situation,and then hydraulic mechanism and rack mechanism were added translational joints and motors were added revolute joints.The joints of manipulator is shown in Fig.3 Fig.2 The simplified model Fig.3 The joints of manipulator Driving Function.First of all,we added drives to translational joints of hydraulic mechanism and revolute joints of motors.We used step function to complete the simulation.The format of step function is step(x, x0, h0, x1, h1)[1].
(1) R1 and R2 are the synthetic curvature radius of meshing tooth surface. h1 and h2 are material parameters.h1 and h2 can be calculated by Eq.2
(3) We set the gear and rack material for steel in the simulation model.Poisson's ratio is 0.29,elasticity is 207000[pa].
Substitute each data into Eq.2, the material parameters of is: R1 can be described by Eq.4[3]
[3] D.Y.Dai:Journal of Shandong Institute of Mining,Vol.7(1988)No.1,p.45(In Chinese)

In this paper, the effect of uncertainty in material parameters on the randomness of the natural frequencies is presented using a new technique called Random Factor Method.
Numerical Examples Fig.1.The graph of rotor system model Fig.2.The graph of simplified calculation model for rotor system The simplified example of a single rotor system shows in Fig. 1, straddle supported rotor using symmetrical structure, m is the equivalent mass of the rotor, taking the rotating shaft as isotropic materials, the stiffness is k.
At the same time, takingthe stiffness of sliding bearing at equivalentstrut as anisotropy materials, along with the horizontal and vertical directions are ,,respectively.
Acknowledgements Supported by the National Natural Science Foundation of China (No. 51175071), the Fundamental Research Funds for the Central Universities (No.N120203001¸N130803001).
Journal of Sound and Vibration 190 (5):821-841. doi:10.1006/jsvi.1996.0095 [3] Zhang Y, Der Kiureghian A (1993) Dynamic response sensitivity of inelastic structures.

It changes the structure of natural environment due to human production and life, establishes material circulation and energy flow which take human and human’s environment as core.
Agricultural ecological environment is good, the mountain vegetables, the middle mountain medicinal materials, the low mountain animal husbandry, forming modern agriculture ecology natural.
Here referring to zero pollution, including traffic construction, housing construction, energy using and so on, they are all the pollution-free raw materials, it really becomes an ecological tourist area.
Acknowledgment This paper is supported by the Humanities and Social Sciences planning fund project of Ministry: Research on Ecological Security Pattern and Landscape Features of Mountain Town Background of Urbanization(12YJA760029) References [1] J.Cheng,L.Lu,X.LJin,J.F.Huang: Mountain Tourism Research and Enlightenment[J].Journal of Natural Resources, 2010 (01)
Advanced Materials Research,2011.

According to the basic premise of material strength theory, when the stress state in somewhere of drill hole wall meets a certain failure criteria, the place will firstly fracture in the failure mode determined by the failure criteria.
The flow rule in plastic flow area is as Eq.3 shows: (3) In the formulas, h and f mean material’s soft and shear dilatancy characteristic parameters; , mean respectively radial and circumferential plastic strain in flow area
Elastic modulus is the material stiffness measurement, and the representation of object deformation difficulty level; while Poisson's ratio is the ratio of transverse deformation and vertical deformation, and is another characterization parameter of material stiffness, and the larger of its value, the larger of expansion amount after material squeezed.
The development and utilization of coal bed methane (coal gas) "twelfth five-year" plan. (2012), p. 1-5 [2] Shen Baohong, Liu Jianzhong, Zhao Luzheng: submitted to Coal Science and Technology(2011) [3] T.K.Perkins L.R.Kern: submitted to JPT(1961) [4] J.Geertsma,J.Deklerk: submitted to JPT(1962) [5] R.J.Clifton&A.S.Abou-Sayed: submitted to SPE(1979) [6] Yan Shaohong, Ning Yu, Kang Lijun ,et al: submitted to Journal of China Coal Society(2000) [7] Li Wei, Yan Tie, et al: submitted to Chinese Journal of Rock Mechanics and Engineering(2009)
[8] Du Chunzhi, Mao Xianbiao, Bu Wankui: submitted to Journal of Mining & Safety Engineering(2008) [9] Chen Linsong.

It is a material parameter.
Acknowledgements This work is supported by the National Natural Science Foundation of China(50878077).
[2] Krajcinovic D.Fonseka G U.Continuous Damage Theory of Brittle Materials,J.Appl.Mech.1981,48:809-824
[4] Wang Xiangdong, Xu Daoyuan: Damage of Concrete Dams and Its Simulation Calculation, Key Engineering Materials,2005,Vol.302,624-629
[5] Qiu Ling, Xu Daoyuan: Study of Initial Damage and damage development of Concrete by compression test, Journal of Hefei University of Technology, 2001,24(6):1061-1065.