基于Hamilton原理的双跨转子系统建模和转子动态特性分析

研究目的：研究双盘双跨转子/轴承/汽封系统在非线性油膜力和非线性汽封力共同作用下的动力学特性,分析了转子转速、密封力、油膜力和联轴器刚度等因素对转子稳定性的影响。创新要点：采用Hamilton原理和有限元方法建立双盘双跨转子/轴承/汽封系统模型,使得双跨多节点的转子系统数值求解更加容易。研究分析转子转速、非线性密封力、非线性油膜力和联轴器刚度等因素对转子稳定性的影响,为大型转子系统的设计提供理论基础。研究方法：采用Hamilton原理和有限元方法建立双盘双跨转子/轴承/汽封系统模型（图1和2）。应用四阶Runge-Kutta法进行数值求解,并采用轴承处、圆盘处的分岔图、时程图、庞加莱映射图、频率图和相轨迹图等来分析转子系统的动态特性。重要结论：1.通过数值计算分析,转子的转速、非线性汽封力、非线性油膜力和联轴器的刚度对双跨转子的稳定性有重要的影响作用。2.随着转速的上升,双跨转子系统从最初的稳定运动,到三倍周期运动,到准周期运动和多倍周期运动交替出现,运动特性相比单跨转子系统要更为复杂。     

Lagrange方程与Hamilton正则方程应用方法的比较

用Lagrange方程与Hamilton正则方程求出同一力学体系的运动规律．分别总结了它们的应用方法，从而比较了两种方法的异同．     

哈密尔顿方程的多种行波解

利用变形映射的方法，得到了一类哈密尔顿方程的丰富的行波解，包括孤子解、三角幂函数解、椭圆函数解。     

The Hamilton System and Hamilton Type Generalized Variational Principle for the Laminated Composite Plates and Shells

lintroductionTileHamilton'systemwasfirstestablishedinthegeometricaloptics,andwasappliedtothetheoreticalmechanicslater.ItsbasicideaistotransformtheEuclidspacetothesymplecticgeometryspaceforcomputing,thatistosay,theLagrangeequationsarechangedintotheHamilton…     

Think it over

This section of Resonance presents thought-provoking questions, and discusses answers a few months later. Readers are invited to send new questions, solutions to old ones and comments, to ‘Think It Over’, Resonance, Indian Academy of Sciences, Bangalore 560 080. Items illustrating ideas and concepts will generally be chosen.     

边q≥C_(p-1)~2+1的(p,q)图的泛圈性

该文给出了n阶(p,q)图当q≥Cp2-1 1时G为泛圈图的充要条件.     

一个有趣的力学模型的守恒量的求解

从一个有趣的力学模型的运动微分方程出发,首先得到了系统的运动积分常数（即微分方程的首次积分）,从而得到系统的Lagrange函数和Hamihon函数,再根据Hamilton函数的形式,由Poisson括号的性质推出了系统的三个守恒量,并对三个守恒量相应的物理意义作了合理的解释。     

搜索问题的分组策略与路径设计

根据搜索宽度和整分搜索区域原则进行人数分组,再根据区域分配的均衡原则确定任务分配,最后把每个方格中心看作图中的点,将搜索问题转化为一个近似的哈密尔顿问题,设计出一条从起点处出发集结于一边中点的“一笔画”路径,而该路径的搜索效率达到95％,即得到的是误差很小的近似最优解。     

Hamilton群上的Cayley图的Hamilton路

本文考虑Ｌｏｖａｓｚ猜想的特殊情形：Ｈａｍｉｌｔｏｎ群上的Ｃａｙｌｅｙ图。证明了有限Ｈａｍｉｌｔｏｎ群Ｆ上连通的Ｃａｙｌｅｙ图Ｇ（Ｆ,Ｓ）具有以任意顶点为起点的Ｈａｍｉｌｔｏｎ路。     

Temporary migration and the institutionalization of strategy

This paper analyzes temporary migration, migration undertaken as a sojourn. Stressing migrant motivation, this paper shows that the institutionalization of intention, or what is here termed strategy, is an important aspect of all migrations. Using this perspective to distinguish between permanent and temporary migration, the author then analyzes the structural patterns and institutionalized sequence common to most temporary migrations. Four aspects of the sequence are discussed: (1) The structural conditions in societies in which temporary migration is most common, (2) Recruitment patterns and network formation linking home and host societies, (3) Patterns of settlement in host societies, and (4) Patternsof return migration. For each aspect, the paper shows that the institutionalization of motives is an important level of migration often left unanalyzed by theorists using social-psychological or macro-level push-pull theories of migration.