应用数学和力学

1996 Vol. 17, No. 3

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On the Mechanism of Turbulent Coherent Structure(Ⅱ)──A Physical Model of Coherent Structure for the Rough Boundary Layer

Liu Yulu, Cai Shutang

1996, 17(3): 189-195.

Abstract(2045) PDF(526)

Abstract:
In this paper,the differences of turbulent coherent structure beween the smooth and rough boundary lavers are analysed.Based on the discussing the transient properties from the smooth wall tothe rough wall,the physicalmodel of coherent structure for the rough boundary layer are established.The width of slwly-moving turbulent spot and the bursting time are obtained,which are in agreement with experimental results.

Dynamic Response of Laminated orthotropic Spherical ShellsIncluding Transverse Shear Deformation and Rotatory Inertia

Yang Yiqian, Ma Hezhong, Wang Junkui

1996, 17(3): 197-203.

Abstract(2092) PDF(453)

Abstract:
In this paper.the equations of motion of axisymmetrically laminated cylindrical orthotropic spherical shells are derived.Theeffects of transverse shear deformation and rotatory inertia are considered.On this basis,the dynamic response of spherical shells under axisymmetric dynamic load is calculated using the finite difference method The effects of material parameters.structural parameters and transverse shear dgformation are discussed.

Weakly Non-Linear Analysis on identification of Vortex, Sound & Heat and Their Interactions in Shear Flow

Ju Hongbin, Zhong Fangyuan

1996, 17(3): 205-211.

Abstract(1841) PDF(466)

Abstract:
The identification of vortex,vortex,sound and heat motions and the interactions among them are discussed by means of velocity vector split and perturbation method in this paper.Especially the shear.flow is considered.All the obtained weakly non-linear equarions have clear physics concept.Basing on the analysis.the interaction between first order sound and vortex.and the creation of the secnd order vortex are studied and some.experiment phenomena of airfoil.flow control by sound are explained.

The Proplems of Nonliear Bending for Orthotropic Rectangular Plate with Four Clamped Edges

Huang Jiayin, Qin Shengli

1996, 17(3): 213-238.

Abstract(2002) PDF(446)

Abstract:
In this paper,under the non-uniformtransverse load,the problems of nonlinear bending for orthotropic rectangular plate are studied by using"the method of twovariable"^[1] and "the method of mixing perturbation"^[2].The uniformly valid asymptotic solutions of Nth-order for ε₁ and Mth-order for ε₂ for ortholropic rectangular plale with four clamped edges are oblained.

Numerical Simulation of Flow of Highly Viscoelastic Flow in Three-Dimensional Varying Thick Slit Channel

Yang Boyuan, Li Yong

1996, 17(3): 239-246.

Abstract(2072) PDF(479)

Abstract:
The distributive law of flow rate is studiedfor highly viscoelastic flow in threedimensional slit channel with varying thickness by using Finite Block Element Method(FBM).As an example.the influence of restrictive block on.flow rate is obtained in fish channel of the plate extruding die and the results of numerical simulation are in concordance withthe approximatical analytical solution.It is proved that FBM can be considered as an important toolfor CAD/CAM.

Elastic-Plastic Constitutive Models Based on the Multiplication Processes of Deformed Grains

He Zongyan

1996, 17(3): 247-258.

Abstract(2259) PDF(548)

Abstract:
According to the characteristics of micro-deformation of polycrystalline metal,the author divides grains intothree kinds and proposes a new conceplion of deformed grains.multiplication,from which some explicit elastic-Plastic constitutive equations can be deduced and some experimental results can be explained quantitativelv,It shows that the macro-yield,rate-correlativity work hardening and other phenomena are all closely related to the kinetic process of grains deformation.

Mathematical Model of a Junction between Linear Elastomer and Thin Plate

Nie Yufeng, Nie Tiejun, Feng Jianhu

1996, 17(3): 259-264.

Abstract(1707) PDF(417)

Abstract:
In this paper,a kind ofjunction problem between linear elastomer elastomer and thin plateis changed.through a well scaling.into an equivalent problem which is studied easily.Then,using an idea of disturbance we have studied the convergence of the displacement vector.field under the action of body.force,which is depending on the thickness of the plate.At last,the variational equations of the limit are obtained.

Two Points Boundary Value Problems in Banach Spaces

Wang Zhihua, Zhang Fengxiang

1996, 17(3): 265-269.

Abstract(2146) PDF(486)

Abstract:
The present paper is concerned with botmdary value problem.for differential inclusions of second order in separable Banach spaces,an existence resuh is proved under weaker conditions and some existence theorems.for nonlinear second order systems can be deduced.form this paper's theorems.

Stability Study of an Unsteady Oscillation Flow

Wang Famin, Zhao Lie, Yu Xin

1996, 17(3): 271-282.

Abstract(1673) PDF(441)

Abstract:
In ihis paper.an instability problem of an unsteady oscillationo flow is studied.In particultar,the phase.function of the disturbance wave.system is soived by using the charocteristic theory of partial differential equation and an expansion of Orysommerfeid eigenvalue problem.instead of using the disturbance model which is given previously The.flow considered is a combination of plane Poiseuille.flow with aflow oscillating periodically and its instability is found for a special initial value of a developing wave due to continuous oscillationg source.

Radar Echo Delay in the(Ω,A_μν)-Field Theory

Hong Tumjudy

1996, 17(3): 283-286.

Abstract(1729) PDF(368)

Abstract:
The present work aims to consider the.fourth test of general relativity theory by Shapiro.using radar echo delay in Yu's(Ω,A_μν)-field theory.