GENERALIZED REYNOLDS EQUATION AND VARIATIONAL INEQUALITY IN LUBRICATION THEORY

This paper has derived generalized Reynolds equationin lubrication theorg in terms of tensor analgsis and S-coordinate system, and has provided corresponding varia-tional inequality. The curved effect of flow of lubri-cant fluid is considered. and the influence of intrinsicproperties of surfaces of axis and axle sleeve on floware counted.     

VARIATIONAL PRINCIPLE AND GENERALIZED VARIATIONAL PRINCIPLE IN HYDRODYNAMICS OF A CLASS OF NON－NEWTONIAN FLUID

ＶＡＲＩＡＴＩＯＮＡＬＰＲＩＮＣＩＰＬＥＡＮＤＧＥＮＥＲＡＬＩＺＥＤＶＡＲＩＡＴＩＯＮＡＬＰＲＩＮＣＩＰＬＥＩＮＨＹＤＲＯＤＹＮＡＭＩＣＳＯＦＡＣＬＡＳＳＯＦＮＯＮ－ＮＥＷＴＯＮＩＡＮＦＬＵＩＤＳｈｅｎＭｉｎ（沈敏）,ＳｕｎＱｉ－ｒｅｎ（孙其仁）（Ｓ...     

EXTENDED VARIATIONAL PRINCIPLE IN NONLINEAR THEORY OF ELASTICITY

From the extended energy functional, a unified variational principle and an extended variational principle are given and proved in this paper. It is about the non-conservative, abrupt and divided domains static (or kinetic) system and by using the undetermined energy functional, we can immediately deduce various variational principles.     

GURTIN VARIATIONAL PRINCIPLE AND FINITE ELEMENT SIMULATION FOR DYNAMICAL PROBLEMS OF FLUID-SATURATED POROUS MEDIA

Based on the theory of porous media,a general Gurtin variational principle for theinitial boundary value problem of dynamical response of fluid-saturated elastic porous media isdeveloped by assuming infinitesimal deformation and incompressible constituents of the solid andfluid phase.The finite element formulation based on this variational principle is also derived.Asthe functional of the variational principle is a spatial integral of the convolution formulation,thegeneral finite element discretization in space results in symmetrical differential-integral equationsin the time domain.In some situations,the differential-integral equations can be reduced to sym-metrical differential equations and,as a numerical example,it is employed to analyze the reflectionof one-dimensional longitudinal wave in a fluid-saturated porous solid.The numerical results canprovide further understanding of the wave propagation in porous media.     

SOME FURTHER GENERALIZATIONS OF KY FAN’S MINIMAX INEQUALITY AND ITS APPLICATIONS TO VARIATIONAL INEQUALITIES

The purpose of this paper is to introduce the concept of generalized KKM mapping andto obtain some general version of the famous KKM theorem and Ky Fan’s minimaxinequality.As applications,we utilize the results presented in this paper to study the saddlepoint problem and the existence problem of solutions for a class of quasi-variationalinequalities.The results obtained in this paper extend and improve some recent results of[1-6].     

ON VARIOUS VARIATIONAL PRINCIPLES IN NONLINEAR THEORY OF ELASTICITY

In the present paper functionals for the various possiblemain variational principles in the nonlinear theory of e-lasticity are derived from the“full energy principle” andseveral of them are not found yet in the literatures avail-able. Through the derivation of this paper we suggest aconjecture on the nonexistence of the eleventh and thesixth classes for the variational principles in Table 6.1of H. C. Hu’s monograph [1].     

VARIATIONAL PRINCIPLES AND GENERALIZED VARIATIONAL PRINCIPLES IN HYDRODYNAMICS OF VISCOUS FLUIDS

In this paper, the variational principles of hgdrodynamic problems for the incompressibleand compressible viscous fluids are established. These principles are principles of maximum power losses. Their generalized variational principles are also discussed on the basis of Lagrangian multiplier methods.     

DUAL CHARACTERS OF INTERACTION BETWEEN PARTICLES AND FLUID

The unique characteristics of gas-solids two-phase flow and fluidization in terms of the flow structures and the apparent behavior of particles and fluid-particle interactions are closely linked to physical properties of the particles, operating conditions and bed configurations. Fluidized beds behave quite differently when solid properties, gas velocities or vessel geometries are vaded. An understanding of hydrodynamic changes and how they, in turn, influence the transfer and reaction characteristics of chemical and thermal operations by variations in gas-solid contact, residence time, solid circulation and mixing and gas distribution is very important for the proper design and scale-up of fluidized bed reactors. In this paper, rather than attempting a comprehensive survey, we concentrate on examining some important positive and negative impacts of particle sizes, bubbles, clusters and column walls on the physical and chemical aspects of chemical reactor performance from the engineering application point of view with the aim of forming an adequate concept for guiding the design of multiphase fluidized bed chemical reactors.     

A SEMI－ANALYTICAL AND SEMI－NUMERICAL METHOD FOR SOLVING 2－D SOUND－STRUCTURE INTERACTION PROBLEMS

Based on the transfer matrix method and the virtual source simulation technique,this paper proposes a novel semi-analytical and semi-numerical method for solving 2-D sound-structure interaction problems under a harmonic excitation. Within any integration segment,as long as its length is small enough, along the circumferential curvilinear coordinate, the nonhomogeneous matrix differential equation of an elastic ring of complex geometrical shape can be rewritten in terms of the homogeneous one by the method of extended homogeneous capacity proposed in this paper. For the exterior fluid domain, the multi-circular virtual source simulation technique is adopted. The source density distributed on each virtual circular curve may be ex-panded as the Fourier‘‘s series. Combining with the inverse fast Fourier transformation, a higher accuracy and efficiency method for solving 2-D exterior Helmholtz‘s problems is presented in this paper. In the aspect of solution to the coupling equations, the state vectors of elastic ring induced by the given harmonic excitation and generalized forces of coefficients of the Fourier series can be obtained respectively by using a high precision integration scheme combined with the method of extended homogeneous capacity put forward in this paper. According to the superposition principle and compatibility conditions at the interface between the elastic ring and fluid, the algebraic equation of system can be directly constructed by using the least square approximation. Examples of acoustic radiation from two typical fluid-loaded elastic rings under a harmonic concentrated force are presented. Numerical results show that the method proposed is more efficient than the mixed FE-BE method in common use.     

APPLICATION OF ARTIFICIAL NEURAL NETWORK TO INVERSE PROBLEMS OF ESTIMATING INNER ETCH OF ELASTOPLASTIC PIPE UNDER PRESSURE

To determine a variation of pipe's inner geometric shape as due to etch,the three-lay-ered feedforward artificial neural network is used in the inverse analysis through observing the elasto-plastic strains of the outer wall under the working inner pressure.Becausc of different kinds of innerwall radii and eccentricity,several groups of strains calculated with computational mechanics are usedfor the network to do learning.Numerical calculation demonstrates that this method is effective and theestimated inner wall geometric parameters have high precision.     

接触问题的互补变分原理及非线性互补模型

给出了接触问题的互补虚功原理,互补能量原理及变分不等式等变分提法,并讨论了三类提法的关系。其此建立了有限维非线性互补模型并给出解的存在唯一性定理。文中还阐明了有,无摩擦接触问题之间以及二维和三维有摩擦接触问题之间的本质区别。     

Strong convergence theorem for a generalized equilibrium problem and a κ-strict pseudocontraction in Hilbert spaces

The main purpose of this paper is to study a new iterative algorithm for finding a common element of the set of solutions for a generalized equilibrium problem and the set of fixed points for a κ-strict pseudocontractive mapping in the Hilbert space.The presented results extend and improve the corresponding results reported in the literature.     

正交各向异性摩擦接触分析的一个二阶锥线性互补法

建立了用于各向异性摩擦接触分析的一个新型互补模型:二阶锥线性互补模型.通过与弹翅性力学的类比,并引入\"线性二阶锥互补\"的概念,将正交各向异性摩擦接触定律表达为一个二阶锥线性互补模型.在此基础上,在参变量变分原理的框架下,建立了正交各向异性摩擦接触问题的有限元列式.由于避免了对摩擦锥的显式线性化,使得该文模型的变量个数较线性互补模型小很多,而解的精度又高很多.文末通过算例,说明了方法对于正交各向异性摩擦接触分析的有效性.     

CrMnFeCoNi纳米晶温度相关的拉伸行为研究

摘要：高熵合金是一种由多种主元元素组成的新型合金。实验研究表明等原子比CrMnFeCoNi高熵合金在低温下具有比室温更高的拉伸强度和断裂韧性。本文针对这一现象,利用分子动力学模拟对平均晶粒尺寸为6 nm的CrMnFeCoNi纳米晶在300、200和77 K下分别进行拉伸模拟。模拟研究揭示了纳米尺度CrMnFeCoNi高熵合金力学行为的温度效应和强韧机理。微结构演化分析表明：低温下,塑性变形阶段,滑移系开动的较少,位错滑移所受的阻力越大,屈服强度和抗拉强度越大;模型破坏时,孔洞缺陷形核较慢,更多孔洞缺陷演化成断口,更多的断口分摊拉伸应变,使得高熵合金纳米晶的低温韧性更好。     

非线性结构分析中三维过渡等参单元及其应力平滑方法

给出了三维四、六、八节点过渡等参元的单元模型,推导了相应的应力平滑公式,编制了计算程序,并通过弹塑性问题和接触问题例题考核,结果良好。     

一类Signorini问题的边界变分不等式

本文讨论了一类简化的Signorini问题.首先将原问题和一个边值问题建立联系,其次将原问题的解分解为不带不等边界条件的变分方程的解和一个变分不等式的解,然后利用边值问题的边界积分方程将变分不等式等价地化解为边界变分不等式.这样原求区域上的第一类椭圆变分不等式问题化解为求一个区域上的变分方程和一个边界变分不等式.最后说明了边界变分不等式解的存在唯一性.文末计算了柱面和半无限刚性基础的摩擦接触问题.结论表明文中方法具有较好的精度.     

工程力学中的互补问题:模型

对互补问题在非线性力学中的一些应用情况给出了较概括的介绍,重点放在了静态接触问题、弹塑性问题以及结构优化问题的互补模型上。将力学问题写成互补模型的好处主要有两点：一是使力学问题有更自然、更精确的数学描述;二是可以考虑用互补问题的有效和强健的数值算法来求解。     

摩擦接触问题的数学规划解法

采用Ｋｌａｒｂｒｉｎｇ等［１］提出的广义摩擦定律，将摩擦接触问题化成一涉及导数的（混合型）参数线性互补问题，并根据Ｋａｎｅｋｏ［２］方法推广得到求解这类问题的算法。典型例题的计算说明该法简单可行。