On the fundamental sloshing frequency in the ice-fishing problemSur la fréquence de ballottement principale dans le problème de la glace avec trous pour pêcher

The sloshing problem is considered in a half-space covered by a rigid dock with apertures. The dependence of the fundamental sloshing frequency on the shape of the free surface region is studied. It is proved that the inequality holds between the fundamental eigenvalues corresponding to two different regions if some conditions are fulfilled. These conditions are verified for particular classes of regions of a fixed area in order to demonstrate that the disk yields the maximum of the fundamental eigenvalue for each of these classes. On the other hand, examples of regions are constructed for which the fundamental eigenfrequency is larger than that for the circular aperture of the same area and even as large as one wishes. To cite this article: V. Kozlov, N. Kuznetsov, C. R. Mecanique 330 (2002) 723–728.     

分析力学初值问题的一种变分原理形式

明确了分析力学初值问题的控制方程，按照广义力和广义位移之间的对应关系，将 各控制方程卷乘上相应的虚量，代数相加，进而在 原空间中建立了分析力学初值问题的一种变分原理形式，即建立了分析力学初值问题的卷积 型变分原理和卷积型广义变分原理. 推导了分析力学初值问题卷积型变分原理和卷积型广义 变分原理的驻值条件. 在建立分析力学初值问题的一种变分原理形式的同时, 将变积方法推广为卷变积方法.     

流向强迫振荡圆柱绕流的涡脱落模态分析

通过求解采用ALE方法描述的运动坐标系Navier-Stokes方程组，分析均匀来流下雷诺 数为150的静止和流向振荡的圆柱绕流. 主要研究了强迫振荡频率和较大振幅比 (A/D=0.3-1.2)对圆柱升力、阻力变化特性以及涡脱落模态的影响. 研究表 明，流向振荡圆柱绕流存在多种涡脱落模态，如对称S以及反对称A-I, A-III, A-IV等多种形式；比较研究结果，拓展了各模态下对应的锁定区域，并将其分为5个 子区；A-I模态中圆柱受力较以前所知更复杂；通过分析计算结果，发现最大加速度 比Af_{c}^{2}/Df_{s0}^{2}可能是涡脱落模态(尤其是对称S模态)最有效的控制参数.     

APPROXIMATE FORMULASOF IMPACT FORCE FOR NORMAL IMPACT OF A FINITE ELASTIC BEAM OF ELASTIC FOUNDATION BY A FINITE ROD

ＲｅｎＷｅｎｍｉｎ（任文敏）；ＨｕａｎｇＪｉａｎｍｉｎ（黄剑敏）；ＣｈｅｎＷｅｎ（陈文）（ＲｅｃｅｉｖｅｄＤｅｃ．２５，１９９４；ＣｏｍｍｕｎｉｃａｔｅｄｂｙＹａｎｇＧｕｉｔｏｎｇ）ＡＰＰＲＯＸＩＭＡＴＥＦＯＲＭＵＬＡＳＯＦＩＭＰＡＣＴＦＯＲＣＥＦＯ...     

Analytical dynamics of continuous medium and its application

综述了国内和国外学者研究连续介质分析动力学问题的进展,阐明了本文主要论述将Lagrange方程应用于连续介质动力学的问题.论文采用Lagrange-Hamilton体系,分别论述了非保守非线性弹性动力学、不可压缩黏性流体动力学、黏弹性动力学、热弹性动力学、刚--弹耦合动力学和刚--液耦合动力学的Lagrange方程及其应用.论述了应用Lagrange方程建立有限元计算模型的问题. 最后,展望了将Lagrange方程应用于连续介质动力学问题的研究前景.     

A Variational Principle for the Revised Goodman–Cowin Theory with Internal Length

In the present study a variational principle is proposed for the revised Goodman–Cowin theory with internal length for cohesionless granular materials (Fang et al. in Continuum Mech Thermodyn in press). The balance equations of the internal variables employed in the theory in equilibrium states, the equilibrium expressions of the constitutive variables and the corresponding natural boundary conditions are derived by use of the proposed variational principle for both cases of compressible and incompressible grains. It is demonstrated that the derived results coincide with those obtained by use of the thermodynamic analysis. The current work serves as a supplementary variational verification of the constitutive theory proposed in Fang et al. (in Continuum Mech Thermodyn in press).     

THE EXACT SOLITARY WAVE SOLUTIONS FOR THE KLEIN-GORDON-SCHR(O)DINGER EQUATIONS

The solitary wave solutions for the Klein-Gordon-Schrodinger Equations were obtained by using the homogeaeous balance principle. The form of the solutions is more generalized than the result that has been proved by pure theoretical and qualitative method in literature;namely, the form of solutions in literature is a particular case of result of the present paper.     

非半单分叉的Normal Form计算

在文［１］基础上，提出一种仅知道派生线性系统零实部特征值时求解非线性系统非半单分叉ＮｏｒｍａｌＦｏｒｍ的方法．通过适当的分类，将要求解的线性代数方程组分为若干相互独立的方程组．将所求系数向量按字典序列排列后，各独立方程组的系数矩阵是上三角矩阵．在非共振情形，各系数向量可按反字典序列递推求出．在共振情形，根据文中的二个定理，巧妙地由一简单的常数矩阵的最大秩子矩阵，定位其系数矩阵的满秩子矩阵，解决了这类方程组的降维简化．通过消元法，把简化后的方程化成类似于半单分叉ＮｏｒｍａｌＦｏｒｍ求解过程中方程的形式，其解法也类似．该方法非常易于在计算机代数软件平台上程序化．     

浓悬浮体的屈服应力和最大填充率

对剪切稀化的浓悬浮体，假设在剪切状态下结构参数变化的速率服从一级动力学关系，在此基础上导出浓悬浮体最大填充率与剪应力、屈服应力与填充率之间关系的数学模型．用硅粉－甘油水溶液及可可粉－可可脂两种悬浮体的实验确认了模型对工业微米级颗粒悬浮体的适用性     

A nonlocal theory for brittle fracture

In this paper, a nonlocal theory of fracture for brittle materials has been systematically developed, which is composed of the nonlocal elastic stress fields of Griffith cracks of mode-I, II and III, the asymptotic forms of the stress fields at the neighborhood of the crack tips, and the maximum tensile stress criterion for brittle fracture. As an application of the theory, the fracture criteria of cracks of mode-I, II, III and mixed mode I–II, I–III are given in detail and compared with some experimental data and the theoretical results of minimum strain energy density factor.