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101.
The unsteady flow of a viscoelastic fluid with the fractional Maxwell model between two side walls perpendicular to a plate is investigated. Exact solutions for the velocity field are established by means of the Fourier and Laplace transforms. The similar solutions for Maxwell and Newtonian fluids can be obtained as limiting cases of our results. In the absence of side walls, all solutions that have been determined reduce to those corresponding to the motion over an infinite plate. 相似文献
102.
Straightness Measurement Using Laser Diode and CCD Camera 总被引:4,自引:0,他引:4
HAO Qun ZHAO Yang LI Dacheng CAO Mang 《Chinese Journal of Lasers》1999,8(3):215-220
1IntroductionInmanufactureandasembleofmodernmachinesandinstruments,anindispensablerequirementisthecontrolofformandpositionero... 相似文献
103.
G. Teters 《Mechanics of Composite Materials》2005,41(5):461-466
Multicriteria optimization of the structure and geometry of a laminated anisotropic composite plate subjected to the thermal
and biaxial action is considered. From known properties of the monolayer and the given values of variable structural parameters,
the thermoelastic properties of the layered composite are determined. The criteria to be optimized—the transverse critical
load and the longitudinal thermal stresses—depend on two variable design parameters of composite properties and temperature.
In the space of the optimization criteria, the domain of allowable solutions and the Pareto-optimal subdomain are found.
__________
Translated from Mekhanika Kompozitnykh Materialov, Vol. 41, No. 5, pp. 683–690, September–October, 2005. 相似文献
104.
Compromise optimization of a rectangular composite plate subjected to biaxial thermal loading and buckling under the action of shear 总被引:1,自引:1,他引:0
G. Teters 《Mechanics of Composite Materials》2008,44(4):325-330
The compromise optimization of the structure and geometry of a laminated anisotropic composite plate subjected to biaxial
thermal shear loading is considered. From the known properties of the monolayer and given values of a variable structural
parameter, the thermoelastic properties of the layered composite are determined. The optimization criteria — the critical
shear load and the longitudinal and transverse thermal stresses — depend on two variable design parameters of composite properties
and temperature. In the space of optimization criteria, the domain of allowable solutions and the Pareto-optimal subregion
are found.
__________
Translated from Mekhanika Kompozitnykh Materialov, Vol. 44, No. 4, pp. 471–478, July–August, 2008. 相似文献
105.
106.
A fourth-order variational inequality of the second kind arising in a plate frictional bending problem is considered. By using regularization method, the original problem can be formulated as a differentiable variational equation, and the corresponding discrete FEM variational equation is presented afterwards. Abstract error estimates and error estimates of the approximation are derived in terms of energy norm and L^2-norm. 相似文献
107.
CHEN Wanji 《中国科学G辑(英文版)》2006,49(2):213-227
Theoretically, the constant stress patch test is not rigorous. Also, either the patch test of non-zero constant shear for
Mindlin plate problem or non-zero strain gradient curvature of the microstructures cannot be performed. To improve the theory
of the patch test, in this paper, based on the variational principle with relaxed continuity requirement of nonconforming
element for homogeneous differential equations, the author proposed the individual element condition for passing the patch
test and the convergence condition of the element: besides passing the patch test, the element function should include the
rigid body modes and constant strain modes and satisfy the weak continuity condition, and no extra zero energy modes occur.
Moreover, the author further established a variational principle with relaxed continuity requirement of nonconforming element
for inhomogeneous differential equations, the enhanced patch test condition and the individual element condition. To assure
the convergence of the element that should pass the enhanced patch test, the element function should include the rigid body
modes and non-zero strain modes which satisfied the equilibrium equations, and no spurious zero energy modes occur and should
satisfy new weak continuity condition. The theory of the enhanced patch test proposed in this paper can be applied to both
homogeneous and inhomogeneous differential equations. Based on this theory, the patch test of the non-zero constant shear
stress for Mindlin plate and the C0–1 patch test of the non-zero constant curvature for the couple stress/strain gradient theory were established. 相似文献
108.
Lamb wave sensors array for nonviscous liquid sensing 总被引:1,自引:1,他引:0
The interdigital transducer (IDT) can excite Lamb wave in a piezoelectric plate loading with a liquid layer, and the phase
velocity of Lamb wave is associated with the properties of the liquid layer. In this paper, the concept of effective permittivity
is introduced to study the Lamb wave’s potential application in liquid sensing. Considering the measuring of ideal nonviscous
liquid, the sensors array is designed to sense the density and the dielectric constant of the liquid layer simultaneously.
Using LiNbO3 as piezoelectric material, in order to improve the sensors array sensitivity and the electro-mechanical coupling coefficient,
the optimized results including plate thicknesses and cut orientations are presented by numerical simulation. These studies
show that the Lamb wave sensors array can be potential in liquid sensing. 相似文献
109.
John Walton 《Surface and interface analysis : SIA》2007,39(4):337-342
Localised corrosion on a microchannel plate has been studied using X‐ray photoelectron spectromicroscopy. Curve fitting to the spectra at each pixel in the image data set reveals the presence of sodium and carbonate species at the corrosion sites, which optical microscopy suggests originated as droplets. It is proposed that aerosol contamination of the alkali enriched microchannel plate during removal of particulate material using a stream of compressed gas was responsible for the initiation of corrosion. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
110.
横观各向同性饱和地基上中厚圆板的非轴对称振动 总被引:1,自引:0,他引:1
研究横观各向同性饱和土地基上中厚弹性圆板的非轴对称振动问题。基于横观各向同性饱和介质Biot波动方程的一般解,按混合边值问题建立了饱和地基与弹性中厚圆板非轴对称动力相互作用的对偶积分方程,并将对偶积分方程转化为易于计算的第二类Fredholm积分方程;采用数值方法求解该积分方程。数值算例结果表明,当h/a>0.05时,饱和半空间体上中厚度圆板在不同频率下的振动特性与相应频率下的刚性板的振动特性基本相同,当h/a<0.05时,板中心的位移将随h/a的减小而增大。 相似文献