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Since fundamental frequency is one of the most important dynamic characteristics of PCB, previous papers studied some factors which would affect the PCB’s fundamental frequency.
Six primary factors which affect the PCB’s fundamental frequency were studied using orthogonal design and variance analysis.
Factors and Levels.
Table 3 Factors and levels Factors Levels 1 2 3 FRE[mm] 150 200 250 REE[mm] 165 220 275 THK[mm] 1 1.5 2 BCa SS SC CC LOb U C D STIFc V H E a See fig. 7(a).
Material properties are shown in tab 1 and FE model is shown in fig. 10.

The process of fatigue crack growth is generally random nature, due to many sources of variability, such as external loading, material properties and geometry conditions.
In this investigation, the fatigue crack growth tests were conducted for five compact tension (CT) specimens of the FSWed 7075-T651 aluminum alloys, base metal (BM), heat affected zones (HAZ) and weld metal (WM), especially three different constant stress intensity factor range (SIFR) controls.
FSW is concerned as one of the most important welding developments in over two decades, because of the advantages which avoids some of the defects seen in conventional fusion welds, and better mechanical properties including low residual stresses.
Regardless of how carefully they are generated, show significant scatter which depends on uncontrolled factors.
As is seen in the Figures, there is not negligible influence of material property, BM, WM and HAZ.

Numerical Analysis on Mechanical Property of Bolted Joint Lihua Yang1,2,a , Zhi Li1,b and Lie Yu1,c 1State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, China 2School of Aerospace, Xi’an Jiaotong University, 28 West Xianning Road, Xi’an 710049, Shaanxi, China ayanglihua_2@126.com, b312629258 @qq.com, cyulie@mail.xjtu.edu.cn Keywords: bolted joint, self-loosing, stress and strain, clamping force Abstract.
Its fatigue and self-loosing will affect the safety of the system.
In this paper, the finite element contact models are built to analyze the mechanical property of bolted joint numerically.
The friction coefficients of contact surfaces are all set to 0.09 and the normal contact stiffness factor is 0.1.
ASME Journal of Mechanical Design, Vol.129, No.1, p. 218-226. (2007)

Research on Influence of Ion-Assisted Deposition to the Optical and Mechanical Properties of SiO2 Film Duoshu Wang1,a, Chongtai Luo1, Tao Chen 1, Yuqing Xiong1, Jizhou Wang1 1 National Key Laboratory of Science and Technology on Surface Engineering, Lanzhou Institute of Physics, P.O.
The result shows that the ion energy, substrate temperature and evaporating rate are key factors that affect the abrasion resistance and transmission of the SiO2 film.
The combination character of these films with substrate is affected severely by depositing process and this lead to a limitation to these hard films in many application areas.
So, three experiments were carried out to study the character of SiO2 film affected by the three parameters.
The absorption can affect the application of SiO2 film seriously.

Grain size influences casting quality and mechanical properties such as yield strength, hardness and ductility.
In order to understand why these factors, i.e. the number density and potency of the inoculant particles, affect grain size we need to understand the role of constitutional supercooling (CS).
It has already been mentioned that temperature gradient is an important process factor but other factors such as interface growth velocity and cooling rate also affect the microstructural outcomes as shown in Fig.11.
Both of the above factors would increase the likelihood of nucleation as the layer grows.
It is also likely that other factors such as scan speed of the AM device will affect the parameters shown in Fig. 11.

S funnel-shaped specimen (GJB1997-94)is made of raw material bar (<22mm) to be suit for the test under corrosive environment, which can be found in Fig.1.The chemical composition and mechanical properties are shown in tables 1 and 2,respectively.
The shape of specimens (Kt=1and Kt=3) for low cycle fatigue test Table 1 The chemical composition of 7XXX Aluminum alloy bar Zn 5.9～6.9 Mg 2.0～2.7 Cu 1.9～2.5 Zr 0.08～0.15 Fe 0.15 Si 0.12 Mn 0.10 Cr 0.04 Ti 0.06 Al allowance Table 2 The mechanical properties of 7XXX Aluminum alloy bar E, Gpa 70.8 σb, Mpa 590.2 Ψ, % 17.92 Ec, Gpa 68.8 σpc0.2, Mpa 555.8 σc0.7,Mpa 578.4 Experiment.The fatigue tests staircase experiment were carried out under room and humid environment.
The humid environment affects the mean value of fatigue strength for pre-corroded 7XXX aluminum alloy with the corrosion-influence-factor of 0.973(Kt=1), 0.971(Kt=3).
The humid environment makes the dispersivity of fatigue life of pre-corroded 7XXX aluminum alloy greater and affect fatigue life eigenvalue and reliability life of 99.9% with the corrosion-influence-factor of 0.7339(Kt=1), 0.8603(Kt=3) and 0.1513(Kt=1), 0.2158(Kt=3), respectively.
Vol.50 No. 9(2008), P. 2588-2595 [8] XiangJin Si: Study on Low Cycle Fatigue Properties of A4 Aluminum Alloy Forging in Corrosive Environments(Nanchang university,Nanchang2007)

Analysis of the evolution of the mechanical properties (tensile and hardness) and the microstructure was done.
Strain per pass is the other major factor that affects grain refinement and homogeneity and the distribution of the mechanical properties.
Thus, the size of the grains and structural homogeneity are significantly affected by processing temperature and strains, affecting.
Fig. 9: A graph of ultimate strength and ductility versus die speed Conclusion From this study, it was found that the major factors affecting the MDF process were; strain per pass, and deformation temperature.
Chen et al., Effect of Temperature on the Mechanical Properties and Deformation Mechanism of a High Mn Steel With Composite Structure, Front.

Conventional and microwave heating performance of modified asphalt recycling test including the rutting test, the trabecular cold bending test, the Marshall immersion test, the freeze-thaw split test, and the splitting strength mechanical properties were test.
Introduction Asphalt pavement in the traffic load and heat, oxygen, light and water under the action of natural factors such as, chemical changes, the aging of asphalt on the road surface, mainly referring to the aging of asphalt pavement material aging and asphalt aggregate of refinement.
Rutting test can fully simulate driving wheels asphalt actual situation of the trial, you can by changing the temperature, load, specimen dimensions, molding conditions and other factors to simulate actual road conditions.
In view of this, this study measured by test mixture when the bending failure at -10 ℃ to evaluate the mechanical properties of asphalt mixture at low temperature cracking resistance.
Mechanical Properties of Asphalt Mixture This study measured by splitting test recycled asphalt mixture mechanical properties.

Effect of the technological additives on the properties of recycled polyolefins.
Polylactic acid: Synthesis, properties and applications.
The ternary blends of tps/pbat/pla films: A study on the morphological and mechanical properties.
I: Thermal, mechanical and morphological properties.
Processing of poly(lactic acid): Characterization of chemical structure, thermal stability and mechanical properties.

Therefore, in order to fully understand the material properties of concrete in different strain rate, it is a important and urgent task to establish a dynamic constitutive equation of concrete correctly.
Strain rate(s-1) 10-5 10-4 10-3 10-2 1 14 16 17 20 2 14 16 18 The formula of fit curve of Fig.3 is expressed as following: (1) 2.2 Dynamic elastic properties of concrete The elastic modulus of concrete reflects the stress-strain properties of concrete.
Conclusions Based on the experiment of typical dynamic mechanical behavior of concrete under uniaxial stress, the affecting factors of dynamic loading rate on the strength and elastic modulus are analyzed in this paper.
Experimental and Theoretical Study On the Dynamic Properties of Concrete [D].
Micromechanics: Overall Properties of Heterogeneous Materials [M].