The solution of large deflection problem of thin circular plate by the method of composite expansion

In this paper, the method of composite expansion in perturbation theory is used for the solution of large deflection problem of thin circular plate. In this method. the outer field solution and the inner boundary layer solution are combined together to satisfy all the boundary conditions. In this paper, Hencky’s membrane solution is used for the first approximation in outer field solution, and then the second approximate solution is obtained. The inner boundary layer solution is found on the bases of boundary layer coondinate. In this paper, the reciprocal ratio of maximum deflection and thickness of the plate is used as the small parameter. The results of this paper improves quite a bit in comparison with the results obtained in 1948 by Chien Wei-zang.     

The singular perturbation method applied to the nonlinear stability problem of a shallow spherical shell (II)

In this paper we consider the nonlinear stability of a thin elastic circular shallow spherical shell under the action of uniform normal pressure with a clamped edge. When the geometrical parameter k is large, the uniformly valid asymptotic solutions are obtained by means of the singular perturbation method. In addition, we give the analytic formula for determining the centre deflection and the critical load, and the stability curve is also derived. This paper is a continuation of the author’s previous paper[11].     

构造几何不敏感四边形膜元的广义协调方法

许多有限元模型在规则网格下具有很高的精度，但当网格畸变程度增大时，其计算精度也随之迅速下降．如何构造出对网格畸变不敏感的单元，长期以来是人们十分关注的课题．本文应用作者早期提出的广义协调方法，构造出具有平面内旋转自由度的任意四边形膜元．该单元不仅列式简洁，而且具有对网格畸变极不敏感的优异性能，为构造对网格畸变不敏感的优质单元提供了一个通用方法     

Double-layered piezo-thermoelastic hollow cylinder under some coupled loadings

In the present paper, a long thick-walled piezo-thermoelastic hollow cylinder with double layers is studied. The effects of temperature on the performance of the cylinder are obtained. Based on the theory of elasticity, the exact solutions of the cylinder under some coupled loadings are found. In the present paper, differences of a piezoelectric parameter between the two layers is taken into account. For comparison, numerical results have been carried out for both double-layered and graded cylinders. At the end of the present paper some discussions are addressed.     

变质量、变阻尼、变刚度结构系统的动力响应

本文首次提出了变质量、变阻尼、变刚度结构系统的动力响应问题,并根据抓斗卸船机的工作过程导出了结构系统的动力方程及解法。最后给出了工程实际算例。     

Die nichtisotherme,laminare, stationäre Spaltströmung einer Newtonschen Flüssigkeit

In the present paper a nonisothermal laminar steady flow of a Newtonian fluid in a flat gap is considered. It is assumed that both the dynamic viscosity and thermal conductivity vary with temperature. For solving the differential equations (momentum and energy principles) governing the problem in consideration two approximate methods are applied, i.e. the “Gauss' principle of least constraint” and the “method of optimal linearization”. In the case when only the dynamic viscosity varies with temperature the results obtained in this paper are compared to the results achieved in paper [9] by using the approximate method of Slezkin and Targ.     

The optimal control of delay control systems with restricted state right endpoint

I.'Introducti0nInthecontroltheory,theresoIutionofoptimalcontrolpr0blems,especiallythePontryaginmaximumprinciple,hasaffordedveryusefuIto0lsfortheadvanceofmodernscienceandthepracticalsystemssuchasthesystemsofmechanica1,economicadministrational,industrialand…     

Numerical simulation of shape memory alloys structures using interior-point methods

This paper is concerned with the numerical simulation of quasi-static evolutions in shape memory alloys structures. In micromechanical models of shape memory alloys, the phase transformation is described by an internal variable representing the volume fractions of the different variants of martensite. In contrast with the framework of standard plasticity, that internal variable is physically constrained to satisfy a set of inequalities at each point. From a structural simulation point of view, handling such local constraints in the evolution problem is not obvious. Robustness and computational time are particularly sensitive issues. In this paper is proposed a new approach which essentially consists in reformulating the non-linear incremental problem as a linear complementarity problem. That approach notably calls for an easy implementation in FEM codes. Comparison with some experimental and numerical results from literature shows the relevancy of the proposed approach.     

Precise control for vibration of rigid–flexible mechanical arm

In the present paper, based on the nonlinear dynamic equation of spacial flexible mechanical arm with dual-link bar, the method of linear quadratic control is used to eliminate the remain vibration of mechanical arm. In the process of computation, the traditional differential algorithm is replaced by the time integration method. Because of taking the more precise time-intervals in the given time-interval and avoiding a lot of computational difficulties, the method of this paper has the characteristics of high precision and unconditional stable. For a typical structure, the precise control law is obtained and the advantages of the algorithm in this paper are shown.     

A linearized and unified yield criterion of metals and its application

ＡＬＩＮＥＡＲＩＺＥＤＡＮＤＵＮＩＦＩＥＤＹＩＥＬＤＣＲＩＴＥＲＩＯＮＯＦＭＥＴＡＬＳＡＮＤＩＴＳＡＰＰＬＩＣＡＴＩＯＮＸｉｏｎｇＨｕｉ－ｅｒ（熊慧而）（ＤｅｐａｒｔｍｅｎｔｏｆＥｎｇｉｎｅｅｒｉｎｇＭｅｃｈａｎｉｃｓ,ＨｕｎａｎＵｎｉｖｅｒｓｉｔｙ...     

一个解剖基人体下肢的生物动力模型--第三部分:肌肉效应

本将人体下肢的肌肉根据其解剖特征，分为５个肌群，并在由本第一部分所建立的基本的解剖基模型的基础上，计入其对人体下肢动力运动的效应。本所建立的５个肌群，则主要代表着膝关节处的运动和稳定肌。最后，作为应用，研究了一个献中的特例。     

Impact of liquid sloshing on the behaviour of vehicles carrying liquid cargo

The purpose of this paper is to study the stability and the behaviour of the dynamics of tank vehicles carrying liquid fuel cargo. Liquid forces and moments due to liquid sloshing is one of the most serious problems strongly related to the instability of tank vehicles. In this paper, a simplified analytical model of liquid sloshing is developed using the Navier–Stokes equations. Simulation results obtained using the full complex Navier–Stokes equations modulated with numerical commercial software are compared to the simplified analytical model. The comparison highlights the validity assumptions used on the analytical model. The results show a good correlation under single or double lane change and turning manoeuvres. In the second part for this paper, a full dynamic vehicle is coupled with the analytical liquid model. This simulation result is compared to a rigid vehicle cargo.     

AN EXACT ELEMENT METHOD FOR THE BENDING OF NONHOMOGENEOUS REISSNER’S PLATE

In this paper,based on the step reduction method and exact analytic method,a new method,the exact element method for constructing finite element,is presented.Since the new method doesn’t need variational principle,it can be applied to solve non-positive and positive definite partial differential equations with arbitrary variable coefficients.By this method,a triangle noncompatible element with15 degrees of freedom is derived to solve the bending of nonhomogenous Reissner’s plate.Because the displacement parameters at the nodal point only contain deflection and rotation angle.it is convenient to deal with arbitrary boundary conditions.In this paper,the convergence of displacement and stress resultants is proved.The element obtained by the present method can be used for thin and thick plates as well,Four numerical examples are given at the end of this paper,which indicates that we can obtain satisfactory results and have higher numerical precision.     

Response of a non-linear system with strong damping to multifrequency excitations

Summary In this paper, a new asymptotic calculation method is presented for a class of nonlinear nonautonomous vibration systems with multiple external periodic interferences. Simple calculation formulae of an asymptotic solution for resonance and off-resonance vibration are derived. The paper is concerned with a vibration system representing a class of nonlinear oscillators. Consequently, the calculation of a class of nonlinear oscillators is routinized. Two different Duffing equations are verified which shows that the results are completely in accordance with the solutions of references [3, 4, 6]. The derivation of solutions of Duffing equations becomes easier and simpler. In addition, some errors in reference [6] are pointed out.     

埋入压电元件的自适应层合板形状控制的数值分析

把压电元件埋入复合材料层合板中，层合板就变成压电自适应层合板，它除了具有承载能力外，还具有检测、动作、变形等功能。本文用有限元法对压电自适应层合板进行了分析，压电元件的驱动效应被等效为力学载荷。计算过程因此得到了简化，所得算例１的计算结果得到了实验结果的验证。在此基础上，利用非线性规划方法，对结构形状的最优控制进行了分析，并给出了算例２的分析结果。     

求解接触问题的一种新的实验误差法

提出了一种带松弛因子的UZAW算法求解实验误差法中给定状态下的位移和接触力满足的等式方程，并证明了该算法是R超线性收敛的。整个区域被划分为多个子区域，不同子区域位移场的求解是独立的。还提出了一种带参数的以不完全因子分解为基础的预条件子共轭梯度法求解不同子区域位移场，该算法在块体规模较大时更加有效。     

Elasto-plastic approach for paper cockling phenomenon: On the importance of moisture gradient

Cockling of paper is a common problem occurring in the production, storage and end-use of paper. It is usually induced by a moisture content change. In many cases, cockling is an irreversible phenomenon; i.e. the initial shape is not obtained although the initial moisture content is restored. This kind of moisture content change occurs in copying machines and in the printing process, for example. In this paper, we present a continuum mechanical model, which is used to study the irreversible cockling of paper. In the model, paper is treated as an orthotropic elasto-plastic material and the model takes into account the small-scale variation of fibre orientation. The model is used to show the importance of the through-thickness moisture gradient on the cockling phenomenon during a cyclic moisture content change. The results suggest that the moisture gradient is a crucial factor for the irreversible cockling.     

爆炸载荷作用下地下圆形结构动态分析

应用有限元方法分析了在爆炸载荷作用下地下圆形结构与土介质的动力相互作用问题。结构与土介质均假定为弹塑性，并用Ｍｉｓｅｓ屈服准则描述，而且考虑其几何非线性的影响。文中使用了人为阻尼边界和模型几何尺寸限制条件，从而大大提高了计算精度。文中还对几种解进行了比较和讨论     

An elasticity solution for axisymmetric problem of finite circular cylinder

In this paper,the complete double-series in the closed region expressing the double-variable functions and their partial derivatives are derived by the H-transformation and Stockes’transformation.Using the double-series,a series solution for the axisymmetric boundary value problem of the elastic circular cylinder with finite length is presented.In a numerical example,the cylinder subjected to the axisymmetric tra(?)s with various loaded regions is investigated and the distributions of the displacements and stresses are obtained.It is possible to solve the axisymmetric boundary value problems in the cylinderical coordinates for other scientific fields by use of the method presented in this paper.     

STOCHASTICITY NEAR RESONANCES IN A KIND OF NEAR-INTEGRABLE HAMILTONIAN SYSTEMS BASED ON SMALE HORSESHOES

In this paper, a method is developed to detect the appearance of stochasticity in a kind of near-integrable Hamiltonian system with two time-scales. One is fast and the other slow. The stochasticity is showed to be chaos in the sense of Smale horseshoes actually.A stochastic web is discovered in our example, by use of the results obtained in this paper.