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.     

非线性粘弹性拟静态问题与非线性弹性静力问题对应原理

本文应用多重单边拉氏变换导出了非线性粘弹性拟静态问题与非线性弹性静力问题的对应关系,从而把过去认为只有线性条件下存在的粘弹性——弹性对应原理拓展到了非线性范畴     

剪切弯曲下短深梁位移数值计算精度的研究

分析了短深梁位移的基本解，评述了有限元解法中关于高次分布力简化为节点力的问题。使用虚功原理和位移线性插值推导了满足二次分布力作用的精确节点力分配公式。通过矩形截面悬臂梁自由终端受集中载荷的算例，阐明了提高短深梁位移计算精度的途径。     

硅微陀螺梳齿驱动的面内失准分析

静电梳齿微驱动器因其结构简单、功耗低、灵敏度高、受温度影响小，成为硅微陀螺仪的主要驱动方式。静电梳齿微驱动器通常由活动梳齿和固定梳齿组成。理想情况下，活动梳齿平行地位于两固定梳齿中心位置。但由于加工误差、驱动结构不对称、扰动等因素，使得活动梳齿相对固定梳齿发生偏转。该文应用能量法及虚功原理，建立了梳齿之间的力与力矩平衡方程。得出了非理想情况下，偏离距离和转角的解析表达式，并分析得出了梳齿间的临界电压。经过数值仿真发现，梳齿面内既偏转又转动时的临界电压小于只发生偏转或转动时的临界电压。     

高分子材料湿度含量对其力学性能的影响的实验研究

本文从实验的角度对湿度因素影响下的高分子聚合物材料的力学性能进行了研究。选用了尼龙6材料进行了一系列的有关湿度实验，通过不同含湿率下与时间相关的材料性能实验首次从实验上证明高分子聚合物材料存在湿度-时间等效性。即对材料力学性能而言延长作用时间与增加材料含湿率与等效的，并且具体给出了尼龙6材料的湿度-时间等效关系。如该材料在不同含湿率下的广义曲线，本文工作为进一步研究湿度因素影响下的材料性能提供了实验依据。     

Fixed Final Time Optimal Control via Simple Cell Mapping

A cell mapping strategy based on Bellman'sPrinciple of optimality (BP) is proposed to solve the fixed final time optimalcontrol of strongly nonlinear systems with state and control bounds. Thefixed final time problem is transformed into a fixed final time-fixed finalstate optimal control problem by reversing the time. This transformationallows to solve the problem in the framework of the BP. Backward searchingalgorithms within the cell mapping context are used to obtain the solution ofthe new problem. This approach reduces considerably the computational effortrequired for the original problem when it is solved by a forward searchingapproach. The vibration control problem of damped and undamped variablestiffness oscillators with bounded stiffness tuning range is studied todemonstrate the effectiveness of the approach. A numerical study on theconvergence of the method is also presented.     

热压电变分原理

热释电介的许多传感器及机敏结构或中的关键材料，本文系统地讨论了在基础理论和数值计算中极具重要地位的各类变分原理，包括准静态变分原理、动态变分原理和关于固有频率的变分原理。最后建立了关于静态压电要板的变分原理，并由此导出了各向异性压电板的控制方程及边界条件。     

Preliminary report on the energy balance for nonlinear oscillations

In this paper, a reliable technique for calculating angular frequencies of nonlinear oscillators is developed. The new algorithm offers a promising approach by constructing a Hamiltonian for the nonlinear oscillator. Some illustrative examples are given.     

大挠度弯曲直梁混合变量最小势能原理的应用

应用大挠度弯曲直梁混合变量最小势能原理,求解均载两端固定大挠度柱面弯曲板条的轴向挠度分布和轴向弯矩分布．实例计算表明:该方法简单实用、精度高,是一种计算大挠度柱面弯曲板条变形的有效方法．     

粘弹性随机分析的虚功原理及随机有限元

利用增量法处理粘弹性本构关系中的遗传积分，将粘弹性材料的随机性、结构几何形状的随机性、外载荷的随机性引入虚功方程，应用摄动方法，研究了粘弹性随机分析的虚功原理和粘弹性随机有限元。研究发现，尽管粘弹性本构关系具有时间相依性，其随机摄动格式并不存在“长期项”的影响，算例表明，应用该方法进行粘弹性结构的随机模拟，计算效率较高、精度较高。