点支承四边自由各向异性平行四边形板自由振动、屈曲和弯曲分析

一个精确的重富立叶级数解析解用于分析四边形自由的点支横观各向异性平行四边形板的自由振动、屈曲和弯曲。解析解用叠加法得到,此解收敛迅速。与现有结果的比较证实了由本法得到的解析解的精确性。文后用图表给出高精度的自由振动、屈曲和弯曲计算结果。     

PATH INTEGRAL SOLUTION OF NONLINEAR DYNAMIC BEHAVIOR OF STRUCTURE UNDER WIND EXCITATION

IntroductionThe dynamic behavior of the nonlinear structure under wind excitation has beenobserved very complicated.Taking guyed masts as an example,only a few collapsingaccidents occurred under extreme atmospheric conditions[1],many took place under mild…     

随机振动数值仿真中基础激励的自动反馈识别

利用ANSYS的APDL(ANSYS Parametric Design Language)语言的强大功能,结合工程实际问题,实现了随机振动试验数值仿真计算中基础输入功率谱的自动反馈识别．反馈过程中使用多个表格来存储基础输入谱,突破了基础输入谱只能用50个以内的数据点来描述的限制,故可以一次性完成基础输入谱的反馈识别,大大提高计算效率与精度．     

FLEXURAL WAVE PROPAGATION IN NARROW MINDLIN''''S PLATE

Appling Mindlin's theory of thick plates and Hamilton system to propagation of elastic waves under free boundary condition, a solution of the problem was given. Dispersion equations of propagation mode of strip plates were deduced from eigenfunction expansion method. It was compared with the dispersion relation that was gained through solution of thick plate theory proposed by Mindlin. Based on the two kinds of theories, the dispersion curves show great difference in the region of short waves, and the cutoff frequencies are higher in Hamiltonian systems. However, the dispersion curves are almost the same in the region of long waves.     

三线性滞回系统的稳态响应

提出了一种三线性滞回阻尼模型。用Krylov-Bogoliubov缓变系灵敏法研究了正弦型激励下单自由度三线性滞回系统的稳态响应。当本文的三线性模型退化为双线性模型时。本文结果与Caughey的结果是一致的。研究结果还发现。这种系统的稳态解总是稳定的，没有振幅的跳跃现象发生。但在激振力力幅达到一定值时能够发生无界响应。此外还发现，稳态振动达到峰值振幅时滞回面积（即最大滞回面积）对峰值振幅的比值和激振力力幅成正比。这个结论与双非线性滞回系统的相应结论是一致的。     

固支圆板安定性的实验研究

本文利用机动法求解固支圆板在循环集中力作用下的安定问题,得到了安定载荷的理论解;利用激光全息的实验方法研究固支圆板的塑性累积现象,测得了安定载荷的上下限,并对实验结果进行了分析研究.     

Behavior of a Cylindrical Drop under Multi-Frequency Vibration

The behavior of an inviscid-fluid drop surrounded by a different fluid under the action of multi-frequency vibration is investigated. The second-order effects in the vibration amplitude are studied. A superharmonic resonance is registered. The stability of the forced oscillations with respect to small perturbations is studied. The condition of the onset of parametric resonance is found. An average drop shape is investigated. The two-frequency case is considered as a particular case of multi-frequency vibration.__________Translated from Izvestiya Rossiiskoi Academii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, 2005, pp. 18–28.Original Russian Text Copyright © 2005 by Alabuzhev and Lyubimov.     

多自由度分段光滑非线性系统的近似解——中华文物龙洗的自激振动

建立了由于摩擦引起的两个弹性体之间自激振动的数学模型.利用平均法求出了由干摩擦引起的多自由度分段光滑非线性动力系统的近似解析解,分析了搓动速度、振动频率与振幅的关系曲线,相位角与搓动速度的关系曲线,分析结果与数值解基本吻合.为研究多自由度分段光滑非线性系统提供了一种有效的近似解析分析方法.     

THEORETICAL AND EXPERIMENTALRESEARCH ON DYNAMIC BEHAVIOR OF GUYED MASTS UNDER WIND LOAD

I. INTRODUCTION Wind-induced vibration is the critical factor for the safety of guyed masts. Many dynamic modelshave been proposed in the literature[1 , 2]. However, there are obvious de?ciencies in many of theseprevious works owing to the poor cabl…