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Optimization of Measuring Points Based on the Grey System Theory for Spindle of Machining Center Changlong Zhao1, a, Xuesong Guan2,b 1 College of Mechanical Engineering, Changchun University，Changchun 130022, China; 2 College of Mechanical Science and Engineering, Jilin University, Changchun 130022, China azhao19790204@126.com, b308989007@qq.com, Keywords: Grey system; thermal error; measuring point optimize Abstract.
There is a reference sequence x0 = {x0 (k) | k = 1, 2, ... , m} and a comparative sequence xi = {xi (k) | i = 1, 2, ... , m}, before calculate the grey correlation coefficient, all of the series standardized data will be processed, this plan can facilitate the comparison in the future, and ensure a equivalence between the factors and the properties of sequence, and ensure the dimensionless and normalized.
Application on grey relational model of temperature field In spindle temperature measuring point of optimization process, introduced the grey relational analysis model, this model can analyze the size of the impact of multiple factors on the main behavior, namely thermal error affecting the spindle temperature measuring point of the most important of the measuring point position, with minimal number of measuring point response to the changes of the temperature field.
Through grey correlation analysis model we obtained the three main factors for the thermal error of spindle.
[6] Yang Jianguo, Deng Weiguo, Ren Yongqiang, Li Yuansheng, DouXiaolong, “Grouping Optimization modeling by Selecting of Temperature Variables for the Thermal Error Compensation on Machine Tools,” China Mechanical Engineering , March 2004, 15(6): 478-481

Thermal properties.
Swelling properties.
By controlling the swelling properties, mechanical strength of scaffold is also can be controlled.
De Vitta, Low back pain and some associated factors: is there any difference between genders?
Santerre, Characterization of a biodegradable electrospun polyurethane nanofiber scaffold: mechanical properties and cytotoxicity, Acta Biomater. 6 (2010) 3847-3855

In addition, the model can be completed with other external factors, for example the wind or snow action.
The CAD software is used to create the solid model, which contains information about the mass & inertia properties of the parts.
In fact, the optimization is made by reducing the angular field of the revolute axes, and the number of steps, without significantly affecting the incoming solar energy.
Petuya, Design of a solar tracking parallel mechanism with low energy consumption, Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 229(3) (2015) 566-579
Barbu, Virtual prototyping tools applied in mechanical engineering, Mecatronica 3 (2004) 9-12

However, multiple PWHT procedures tend to degrade the mechanical properties of steel and design standards have set limits on the length of time PWHT can be carried out before steel should be replaced.
To date, this has been best applied by the aerospace and nuclear industries [2], where the techniques of fracture mechanics have been used to enable safe design using low empirical safety factors.
The properties observed are the tensile properties, the impact transition temperature as determined using Charpy impact specimens and the reference temperature as determined by ASTM E1921.
Table 1 Minimum tensile properties for ASTM A106/B.
Table 3 Tensile properties of the four conditions.

However, the defects in the disk, such as heat induced hole, previous particle boundary (PPB), non-metallic inclusions, have been one of the important factors to perplex development and quality level of P/M superalloy.
Many factors affect the amplitude of echoes, in addition to the size of inclusions, the properties, orientation, surface roughness and shape will influence the echo height of inclusion.
Fig.12 Reaction zone between Al2O3-SiO2 inclusion and matrix (a)SEM of Al2O3-SiO2 inclusion (b)Surface scanning of Al2O3-SiO2 inclusion Fig.13 Crushing effect of extrusion on Al2O3-SiO2 inclusions Results of mechanical properties test.
Tin, Nickel-Based Superalloys for Advanced Turbine Engines, Chemistry, Microstructure and Properties, Propul Power. 22(2006) 361-365
Chen, Influence of Inclusion on the Stress Intensity Factors under Thermo Mechanical Loads in a P/M Superalloy, Appl.

As a case study, mechanical properties of Al3004 which has wide range application in high-velocity forming are measured and used in the model.
Hence, this factor must be determined accurately.
All measured properties of Al3004 are collected in Table 1.
However, it should be noticed that plastic properties of material is sensitive to strain rate, so updated material properties should be imported into model based on Eq.3.Velocity boundary conditions facilitate producing high strain rates.
D., “High velocity formability and factors affecting it”, Ph.D.

These characteristics have become important factors which will restrict the FTS system’s processing capacity and processing accuracy.  
In order to reduce load of high-frequency movement, and to improve dynamic performance, moving parts of this tool holder adopts hollow structure, whose structure is optimized for ensuring its stiffness not to be affected. 2.2 Technique system modeling The operating principle of mechanical parts and circuit part of FTS system is shown in Figure1(b).
The mechanical part is a typical spring-mass-damper system, whose transfer function Gm(s) is shown as follows: (1) where，K'=kp/(kp+k),,.
It can be obtained that 1) Amplitude attenuation and phase angle offset increase with input signal increasing. 2) In the state of low-frequency, FTS system’s displacement attenuation is similar to mechanical system’s displacement attenuation.
Design of diamond-turned holograms incorporating properties of the fabrication process.

Simulation of fiber orientation in dumbbell-shaped injection cavity Hong He1, a, Xiongbing Chen1,b 1College of Mechanical and Electrical Engineering, Beijing University of Chemical and Technology, Beijing China Engineering Research Center of the Ministry of Education for Polymer Processing Equipment, Beijing China a,bemail hehong@mail.buct.edu.cn Keywords: fiber orientation, dumbbell-shaped cavity, simulation, injection Abstract.
Understanding rules of the distribution of fiber is important to control the mechanical properties of composite material performance.
The calculation results verified demonstrated that the shape of injection cavity affected the fiber orientation.
In order to get the desired the mechanical properties of the final composite product, understanding rules of the distribution of fibers in the flow field of injection molding process is very important.
The Governing Equation For isotropic flow field of thickness concentration suspension, the interaction between fibers and fiber rotary motion were considered in fibers orientation control equation, Fokker Planck equation: (3) Among them; is differential operator; ωij is vortex tensor; is tensor of deformation rate; λ is fiber shape factor, is fiber rotational diffusion coefficient, Ci is interaction coefficient between fibers.

The modal analysis shows the bending and torsion deformations are the main factors influencing the dynamic performances of the beam when working frequencies are close to the first six natural frequencies; therefore, the selected spindle rotational speed should keep away from the natural frequencies of the beam when planning the cutting parameters.
Finite element model The three-dimensional (3-D) solid model of the beam was established by Solidworks software, whose overall size was 3905mm×1110mm×1000mm.Taken into account the efficiency of the subsequent analysis, some of small properties were simplified.
The material of the beam was HT300 and its physical properties were given in Table 1.
Table 1 Physical properties of beam Young modulus [GPa] Poisson ratio Density [kg/m3] 130 0.27 7200 The FE model in coordinate system is shown in Fig. 1.
(2) The modal analysis shows the bending and torsion deformations are the main factors influencing the dynamic performances of the beam when working frequencies are close to the first six natural frequencies; therefore, the selected spindle rotational speed should keep away from the natural frequencies of the beam when planning the cutting parameters.

The essence of the problem is not the methodology of calculation but knowledge of damping coefficients, the influence of different types of seabed, effects of waving and other factors in the model of detonation.
Stiffness matrix K reflects the material properties of the element and geometry.
The nature and mechanism of the explosion is determined by numerous parameters, which include: • material properties (physical, chemical stability, heat of combustion, etc
Folęga, The study of the dynamic properties of some structural components of harmonic drive, Journal of Vibroengineering, 15(4) (2013) 2096-2102
Węgrzyn, The influence of nickel and nitrogen on impact toughness properties of low alloy basic electrode steel deposits.