小型平板蒸汽腔的实验研究

平板蒸汽腔的加工工艺一直都有待改进,其工艺的质量直接影响着工作性能.本文基于平板蒸汽腔的工作原理,设计、加工了一种小型平板蒸汽腔,并进行了实验研究.文中介绍了其工作原理,加工工艺以及实验结果.结果表明:该小型平板蒸汽腔具有较好的工作性能,其厚度为5 mm,当输入热流为22.1 W时,平板蒸汽腔的热阻低至0.01°C/W...     

改进型分形波带片的焦深特性研究

提出了一种具有增大焦深特性的改进型分形波带片(FZP).分析并推导了改进型分形波带片基于优化参数w的周期公式;计算了改进型分形波带片在菲涅耳近似下的衍射光场分布以及对应的横向光场分布特性因子,包括分辨率因子(G),施特雷尔比(S)以及旁瓣强度因子(M);同时分析了在不同的径向坐标r和r2下的改进型分形波带片的焦深特性,...     

Crystal structure of aluminum sulfate hexadecahydrate and its morphology

A single‐crystal structure of aluminum sulfate hexadecahydrate (Al₂(SO₄)₃·16H₂O) was captured with a polarizing microscope. The structure was similar to a hexagonal plate and consistent with the predicted morphology derived from the modified AE model. An octagonal plate morphology was first obtained in a vacuum but was transformed into hexagonal plate‐like when the effect of the solvent with two disappearing {1 1 0} and {1 0 −1} faces was considered.     

Multicriteria optimization of a rectangular composite plate subjected to longitudinal thermal stresses and buckling in shear loading

The multicriteria optimization of the structure and geometry of a laminated anisotropic composite plate subjected to thermal and shear loading is considered. From the known properties of the monolayer and given values of variable structural parameters, the thermoelastic properties of the layered composite are determined. The optimization criteria — the critical shear load and the longitudinal 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. 43, No. 1, pp. 85–92, January–February, 2007.     

The construction of plane elastomechanics and Mindlin plate elements of B-spline wavelet on the interval

Based on two-dimensional tensor product B-spline wavelet on the interval (BSWI), a class of C0 type plate elements is constructed to solve plane elastomechanics and moderately thick plate problems. Instead of traditional polynomial interpolation, the scaling functions of two-dimensional tensor product BSWI are employed to form the shape functions and construct BSWI elements. Unlike the process of direct wavelets adding in the previous work, the elemental displacement field represented by the coefficients of wavelets expansions is transformed into edges and internal modes via the constructed transformation matrix in this paper. The method combines the versatility of the conventional finite element method (FEM) with the accuracy of B-spline functions approximation and various basis functions for structural analysis. Some numerical examples are studied to demonstrate the proposed method and the numerical results presented are in good agreement with the closed-form or traditional FEM solutions.     

Detachment of a Beam Glued to a Rigid Plate

The contact problem of detachment of an elastic beam glued to a rigid plate is considered. A mathematical model is proposed and theoretical results are compared with experimental data.     

Physically nonlinear problems of stress concentration in members,structures, and buildings

Results from studies of stress concentration in physically nonlinear elastic structural members are reviewed __________ Translated from Prikladnaya Mekhanika, Vol. 43, No. 1, pp. 93–99, January 2007.     

Hydromagnetic flow at an oscillating plate

Uniformly valid solutions are obtained for the hydromagnetic flow at a moving plate and at an oscillating plate. In each case, two different representations for the solution are presented. On one representation a half order fractional operator is used, whereas the other representation did not rely on fractional operator. Solutions for special cases of the oscillating plate are calculated for finite times. Furthermore, the effects of the nondimensional numbers M (the magnetic parameter), Re (the suction Reynolds number) on the flow are compared with the existing results and are discussed.     

Reply to Comments on “Non-Darcian Forced Convection Flow of Viscous Dissipating Fluid over a Flat Plate Embedded in a Porous Medium”

In this note, we reply to the comments by Rees and Magyari (2007) on our article (Aydin and Kaya 2007). They mainly stated that the thermal boundary conditions we defined at the edge of the boundary layer were incompatible with the energy equation. This is questionable and therefore we will discuss it below. They disclosed that our results were in error. However, this is quite misleading. Scientifically, they cannot reach such a conclusion without comparing our results with what they thought to be correct. In fact, this misleading and unproven statement will be shown not to be correct in the following.     

New boundary element formulas for the biharmonic equation

We propose two new boundary integral equation formulas for the biharmonic equation with the Dirichlet boundary data that arises from plate bending problems in ℝ². Two boundary conditions, u and ∂u/∂n, usually yield a 2 × 2 non-symmetric matrix system of integral equations. Our new formulas yield scalar integral equations that can be handled more efficiently for theoretical and numerical purposes. In this paper we supply complete ellipticity and solvability analyses of our new formulas. Numerical experiments for simple Galerkin methods are also provided. This revised version was published online in June 2006 with corrections to the Cover Date.