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 The purpose of this paper is to provide a theoretical model of tidat strain ror practical application. This model consists of two parts, i.e., body tidal strain as a consequence of the attraction by the sun and the moon and loading tidal strain caused by the action of ocean tides. For the former, in order to save computation time, we start from Wahr's tidal model, but make a few simplications, so that the components of strain tensor can be obtained from the tidegenerating potential directly. As to the latter,... The purpose of this paper is to provide a theoretical model of tidat strain ror practical application. This model consists of two parts, i.e., body tidal strain as a consequence of the attraction by the sun and the moon and loading tidal strain caused by the action of ocean tides. For the former, in order to save computation time, we start from Wahr's tidal model, but make a few simplications, so that the components of strain tensor can be obtained from the tidegenerating potential directly. As to the latter, the effects of four main ocean tides, i.e., M2, S2, O1, K1, are taken into consideration. The eotidal maps used are Schwiderski's global maps associated with the local maps of China Sea.  本文的目的是建立一潮汐应变的理论模型,以供使用。模型由两方面组成,即日月引力导致的体潮应变及海洋负荷作用产生的负荷潮汐应变。前者,我们从 wahr 的潮汐模型出发,进行适当简化,从引潮位直接算出各应变分量,以提高计算速度;后者,我们使用了 M_2,S_2,O_1及 K_1四个主要海洋潮波的迭加,海图采用了 Schwiderski 的大洋图并顾及我国的局部潮图。  This paper mainly deals with the single grazing impact phenomenon of the rubimpactrotor system by using the method of Poincare map analysis. As we know, rubimpacts of rotorsystems are always suddenly occurring and hardly predictable. The recent research indicates thatthe rubimpacts are intimately related to a phenomenon called grazing impact, which is in facta critical rubimpact when the rotor touches the stator with very low radial velocity that nearlyequals 0. of cause, it is quit difficult to set up a... This paper mainly deals with the single grazing impact phenomenon of the rubimpactrotor system by using the method of Poincare map analysis. As we know, rubimpacts of rotorsystems are always suddenly occurring and hardly predictable. The recent research indicates thatthe rubimpacts are intimately related to a phenomenon called grazing impact, which is in facta critical rubimpact when the rotor touches the stator with very low radial velocity that nearlyequals 0. of cause, it is quit difficult to set up a theoretical system for the general case of rubimpact, which includes the single impact, the multiple impacts and the wholly whirling.impact.But it is somehow an easily thing to investigate the motions of the rotor system with the singleimpact since the rotor touches the stator only once a period. Now, a certain trajectory (grazingorbit) is chosen and a local map is constructed near the trajectory. Then the local dynamicalbehavior can be obtained by study of the map. Because of the discontinuity of stickness in the rubimpact rotor system, the flow in the phasespace is not smooth and even discontinuous. Those common measures for the smooth dynamicalsystems, such as the method of central manifold and linearizing of the system ill the neighborhoodof the fixed point, become invalid. However, enlightened by the significant work of S. W. Shawand A. B. Nordmark, the method concerned in the nonsmooth dynamic system of single degreeof freedom is successfully applied to the rubimpact rotor of two degrees of freedom in this paper.And some special dealments including the theory of limits for sequences and singular analysis areused to determine the stability of the fixed point of the Poincare map, and also the attracted regionis found for the fixed point.A further study gives the interesting result of the grazing bifurcation for the nonsmoothdynamical system. It is turned out that the appearance of grazing impact causes the uncertaintyto the motion of the rotor system and changes its stability. It may be the stable periodic motionbefore the grazing impact, but if the grazing impact occurs, the stability of the motion can beeither stable or unstable. Soon after that, chaos will follow it. The essence of this phenomenonis just because of the nonsmooth characteristic of the system. That is, the grabing bifurcationcauses the square root singularity in the impact map whiCh makes the Jacobian of the map nosense as rotor touches the stator with zero radial velocity. When the motion of the rotor systemis near the grazing impact, it experiences stable periodic motions, grazing bifurcation to irregularrubimpact motions with the variation of the system parameters.  通过建立转子系统碰摩的Ｐｏｉｎｃａｒｅ映射，将对非光滑碰摩系统的研究转化为对Ｐｏｉｎｃａｒｅ映射的分析．文中主要对转子碰摩当中一类特殊的运动形式──单点碰摩下的擦边现象进行了详细研究．从序列的极限理论出发分析了该映射的周期不动点的稳定性及其吸引域：得到了转子系统在接近擦边运动时解随系统参数变化的分岔情形．  Based on the Volterra expansion of nonlinear dynamical system functions and the deterministic and nonlinear characterization of the chaotic signals,an adaptive higher\order nonlinear Fourier infrared(HONFIR)filter is proposed to make prediction of chaotic time series.The time domain orthogonal algorithm is taken to update filter's coefficients.A higher\order nonlinear adaptive filtering scheme is suggested in order to track current chaotic trajectory by using preceding predictive error for adjustign filter... Based on the Volterra expansion of nonlinear dynamical system functions and the deterministic and nonlinear characterization of the chaotic signals,an adaptive higher\order nonlinear Fourier infrared(HONFIR)filter is proposed to make prediction of chaotic time series.The time domain orthogonal algorithm is taken to update filter's coefficients.A higher\order nonlinear adaptive filtering scheme is suggested in order to track current chaotic trajectory by using preceding predictive error for adjustign filter parameters rather than approximating global or local map of chaotic series.Experimental results show that:(1)this adaptive HONFIR filter can be successfully used to predict hyperchaotic time series;(2)the prediction capacities of the HONFIR filter is related to its nonlinear function,but not determined by the HONFIR filter's degree of nonlinearity;(3)the adaptive prediction performance of the HONFIR filter is not confined by the Takens embedding dimension;(4)the proposed HONFIR filter can have some anti\noise ability.  根据混沌序列产生的确定性和非线性机制 ,基于Volterra级数展式和混沌序列高阶奇异谱特征 ,提出了一种高阶非线性傅里叶红外 (HONFIR)滤波预测模型用于混沌时间序列的自适应预测 .其自适应算法采用时域正交算法来自适应地跟踪混沌的运动轨迹 ,而不是重构混沌系统的全局或局部运动轨迹 .实验研究表明 :(1)这种HONFIR自适应滤波器能够有效地预测一些超混沌序列 .(2 )预测混沌序列的性能与预测模型的非线性拟合能力有关 ,但并非非线性程度越高 ,预测性能就越好 .(3)当HONFIR滤波器对混沌序列的非线性拟合精度高时 ,其自适应预测的性能与其输入维数的关系不受Takens嵌入定理的约束 .(4)HONFIR自适应滤波器具有一定的抗噪能力 .   << 更多相关文摘 



