Transient Responses of Flexible Non—uniform Spinning Shaft with Nonlinear and Asymmetric Supports

In this paper ,a hybrid approach was developed to investigate the transient responses of a multi-span non-uniform flexble spinning shaft with nonlinear and asymmetric supports.The non-uniform spinning shaft with variable parmeters was modeled as a Bernoulli-Euler beam column with sectional constant cross-section properties by the finite element method.The supporting stiffness behavior of the nonlinear supports was described as a piecewise-linear and asymmetric model.The equations of motion in the matrix form of a multi-span non-uniform spinning shaft with nonlinear and asymmetric supports were formulated using Hamilton‘s principle and the assumed mode method.As an example,a spinning rocket with many variable stiffness supports was numerically simulated by the direct integration method.The transient response and dynamic behavior of this rotate-dynamic system are analyzed.     

NTM方法在非线性贝叶斯动态模型中的应用

将NTM方法应用于非线性贝叶斯动态模型，给出了它的递推公式以及随机变量的数字特征的计算，与蒙特卡洛方法相比提高了效率和精度.     

非线性常差分方程守恒量的计算

给出了计算非线性常差分方程守恒量的一种方法,利用此方法可计算出非线性振动方程差分格式的守恒量．     

形变映射方法和非线性WBK方程的研究

拓展了形变映射方法，以非线性WBK水波方程为例，获得系统丰富的解析解，包括孤波解，周期波解，雅可比椭圆函数解和其他精确解．     

用拉压不同模量理论计算支座移动引起的超静定结构内力

For statically indeterminate structure, the internal force will be changed with the translation of the supports, because the internal force is related to the absolute value of the stiffness EI. When the tension is different with the compression modulus, EI is the function of internal force and is not constant any more that is different from classic mechanics. In the other words, it is a nonlinear problem to calculate the internal force. The expression for neutral axis of the statically indeterminate structure was derived in the paper. The iterative program for nonlinear internal force was compiled. One case study was presented to illustrate the difference between the results using the different modulus theory and the single modulus theory as in classical mechanics. Finally, some reasonable suggestions were made for the different modulus structures.     

汇率干预中的多点自由边值问题的数值计算方法

1IntroductionIt is i mportant for the economic development of acountry to maintain the stabilization of exchange rate,so the intervention of exchange rate has become thetopic of the main concerns of the economic and math-ematical circles[1-5].To maintain the stabilization ofexchange rate,many countries use target zone re-gi mes,that is,the central banks intervene in the for-eign exchange market such that the exchange ratestays within the interval[a,b].There are fixed costand cost proportional …     

几何刚度矩阵的推导和应用

以虚功原理为基础有限元进行梁柱的分析，应用很少，主要是于在计算中，荷载很小时，计算结果就不收敛了。因而也就很难应用于工程分析中。以虚功原理为基础推导得出了几何刚度矩阵，分析了计算不收敛的原因，得出结论：不考虑节点力因位移产生的不平衡力对几何刚度矩阵的影响，是计算结果不收敛的主要原因。算例说明了当考虑了这个影响以后，计算结果和文献给出的计算结果符合良好。     

间接干预的物价的微分方程模型

在已有物价模型的基础上,结合中国特殊的不成熟的市场经济环境,对原模型进行修改和补充,把货币供给量对物价的影响加进去形成了新的间接干预物价的微分方程模型.首先利用非线性微分方程相关理论讨论了模型的稳定性和分支等数学特征,然后通过数值模拟进一步分析验证,最后介绍了模型结果在经济意义下对物价分析的解释和应用.     

基于Matlab GUI的薄膜干涉仿真

为动态反映薄膜干涉图样随波长和干涉装置的几何参数的改变而产生的变化,利用Matlab图形用户界面的设计和开发功能,结合真实的可见光谱,制作了劈尖干涉、牛顿环干涉以及迈克尔逊干涉的交互式图形仿真界面.仿真结果图形细致逼真,使该过程的物理规律直观形象,有助于学生理解这几种典型薄膜干涉过程中的物理规律.     

一阶中立型非线性微分方程解的振动性

本文首先给出了一阶具有正负系数的中立型微分不等式解的振动准则，然后应用该准则研究了一阶中立型非线性微分方程，获得其解振动的判别准则．