剪切变形

By using of the first order shear deformation shell theory, the strain-displacement relationships were presented.

采用Hamilton原理、压电理论和层合板壳的一阶剪切变形板壳理论，推导了压电层合板壳系统的运动方程。

The equations of buckled equilibrium were derived based on the displacement field of the first order shear-deformation theory.

用一阶剪切变形理论的位移场推导出5个屈曲平衡方程。

By using virtue work principle and first order shear plate theory,the finite element formulations of piezoelectric sensors and actuators arederived.

给出了采用虚功原理及一阶剪切变形理论导出的压电传感和作动有限元方程。

By using o f the first order shear deformation shell theory, the strain-displacement relat ionships were presented.

采用Hamilton原理、压电理论和层合板壳的一阶剪切变形板壳理论，推导了压电层合板壳系统的运动方程。

A first order shear deformation theory of piezoelectric shell was proposed, which is based on Hamilton's principal, linear piezoelectricity theory and first order shear deformation laminated shell theory.

提出了一种压电层合板壳的一阶剪切变形理论。

The series solution of lateral free vibration of variable cross--section cantilever beam, when shear flexibility is taken into account, is given in the dissertation.

对上述截面变化规律的弯曲悬臂杆，当考虑剪切变形时，其自由振动微分方程为变系数的四阶微分方程。

This paper mainly consists of three parts:(1) Based on the Reddy's higher-order shear deformation plate theory and general von Kármán-type equations, put forward the governing equations of pre- and post-buckled vibration of several hybrid FGM plate forms which have not been studied adequately, triumphantly applying the perturbation technique combined with Galerkin method into equations solving, and get the comparatively simple result forms with complicated deduction at last;(2) As a new type of materials, piezoelectric fiber reinforced composite actuators were applied to optimal vibration control, interrelated informatons be depicted in this paper;(3) During the investigative cource, some factors not been considered adequently in other researches were discussed fully in the postbuckled vibration analysis, such as the temperature-dependent material coefficients, heat conduction and nonlinear vibration characteristic etc.

本文的研究工作主要包括：(1)基于Reddy高阶剪切变形板理论和广义Kármán型方程，给出了几类现有研究成果较少或没有彻底解决的FGM混合板结构的屈曲前和屈曲后振动特性研究的控制方程，成功将摄动-Galerkin混合法应用于求解过程，并给出了各控制方程相对直观且易于计算的解析解形式；(2)单向压电纤维增强复合材料(Piezoelectric Fiber Reinforced Composite，简称PFRC)是一种新型压电材料，本文将其应用到了结构振动控制研究当中，发现通过压电纤维体积含量的选择可以实现混合板结构的优化振动控制；(3)围绕几种有代表性的FGM混合板结构，讨论其屈曲后的振动特性，在分析中同时考虑热传导，材料物性参数的温度相关性，以及机/热/电荷载耦合效应对非线性振动特性的影响，最后给出了大量数值计算结果。

The main research contents are stated asfollow: 1. Simplified analysis method of space grids structuresDouble-layer space grids have been assumed as sandwich plate, and are analyzed bythe nontraditional theory of plate with consideration of shear deformation and threegeneralized displacements. Using the theory of energy variation, simplified methodsfor bending, stability and vibration analysis of double-layer space grids have been putforward based upon the idea of split rigidity. The formulas for calculating internalforces, displacements, critical load and natural frequency have been given out. Set thestable cables and bearing cables in hyperbolic paraboloid cable nets are all replaced bytruss-cable to form truss-cable nets structures. Natural vibration analysis method fortruss-cable nets structures has been put forward using the energy variation method andRayleigh method.

主要内容包括： 1、空间网格结构静动力简化分析方法把网架结构简化为夹层板，采用考虑剪切变形的具有三个广义位移的平板弯曲理论进行分析，基于分解刚度思想利用能量变分原理提出了网架结构弯曲、稳定与振动分析的简化计算方法，给出了位移、内力、屈曲临界荷载和固有频率的计算公式；将双曲抛物面索网中的稳定索与承重索均用劲性索代替形成劲性索网结构，基于能量变分法和Rayleigh法给出了劲性索网结构固有振动分析的简化计算公式。

A considered shear deformation affect, exactitude multi-segment bar member s stiffness matrix was deduced by structural mechanics principle.

利用结构力学原理推导得出了考虑剪切变形影响的精确多分段杆单元模型的单元刚度矩阵。

Accurately considering the axial extension and first order transverse shearing deformation, the geo metrically nonlinear governing equations for functionally graded Timoshenko beam subjected to mechanical as well as thermal loads were established. In the analysis it was assumed that the material properties of the beam vary continuously as a power function of the thickness.

在精确考虑轴线伸长和墓于－阶横向剪切变形理论的基础上建立了功能梯度Timoshenko梁受热－机载荷作用时的几何非线性控制方程，其中功能梯度梁的材料性质采用了沿厚度方向按照幂函数连续变化的形式。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。