数值稳定性

Based on investigating the short and intermittent structural plane, surrounding rockmass of the huge underground powerhouse in Three Gorge has been divided into five statistical similar areas according to its characteristic of rockmass structure by applying structure plane network simulation. Distributed characteristic of structural plane has been studied and based on it mechanics macrocharacteristic has been studied:(1) It is the first time that based on the result of structural plane network simulation rockmass quality of every structure area has been studied with applying blurred information optimum seeking technique and be compared with and RQD method. The result indicated that it has better effect to evaluate rock quality with blurred information optimum seeking technique.(2) It is the first time that the interrelated relationship of the result of in-suit rockmass deformation test and fractal characteristic of structure on test point has been applied to determine rockmass deformation parameter. The question of evaluating deformation parameters of engineering rockmass has been solved.(3) Anisotropy strength parameters have been determined by applying shear zones simulating method. The result indicated that there are different strength parameters in every structural area, after comparing the result of Fast Lagranian Analysis in continua number simulation method with that of method of weighted mean according to continuity. The result indicated that when a suitable reduction coefficient is been considered rockmass strength parameters can be simply and fast determined with method of weighted mean according to continuity where there is not enough test result.(4) Damage characteristic has been studied based on analysis fractal characteristic of structural plane network by applying fractal-damage coupling method. It is the first time that the concept of damage degree has been set up to evaluate rockmass quality according to the biggest principal damage.

通过对短小、断续性结构面统计特征的研究，将地下厂房区划分为五个岩体结构统计均质区，应用结构面网络模拟技术研究了各个岩体结构均质区结构面的发育分布特征，并以此为基础对岩体宏观力学特性进行了深入研究：(1)首次通过在结构面网络模拟计算结果的基础上，应用模糊信息优化技术研究了厂房区各个岩体结构分区的岩体质量并与岩体基本质量指标研究法、岩体质量指标RQD值研究法作了对比，结果表明以结构面网络模拟结果为基础，应用模糊信息优化技术进行岩体质量评价能够取得很好的效果，解决了工程岩体质量的定量评价问题；(2)首次通过对已有的现场大型岩体变形试验结果的分析及相应试验点岩体结构分形特征的研究，建立了结构面分布的分形维数和岩体变形指标间的相关关系，并首次应用这种相关关系根据结构面网络模拟及分形维数计算结果确定了缺少试验结果的地下厂房各工程部位的岩体变形指标而且应用于围岩稳定性计算，解决了工程岩体宏观变形参数的评价问题；(3)应用在结构面模拟网络图上模拟岩体剪切破坏带的方法，得出了岩体在不同方向上的强度参数，结果表明岩体的强度特性与结构面的发育方向和程度有着明显的关系，各个岩体结构均质区具有不同的强度参数；同时还通过应用拉格朗日差分法对岩体强度指标的数值分析并与按连通率加权平均计算法对比表明，按连通率加权平均计算法在考虑合理的折减系数情况下，可以简单快速地对缺少现场大型试验结果的具体工程部位实现岩体强度指标的估计，通过以上研究解决了工程岩体抗剪强度参数的评价问题；(4)通过结构面网络分形维数的研究，应用分形损伤耦合分析方法，研究了厂房区岩体的损伤特征，并首次引入"损伤度"的概念，建立了应用最大主损伤评价岩体质量的指标体系。

The basic idea was to discrete the structure and find the load function according to the energy criterion of buckling and the principle of random displacement method. As the critical load is the minimum of the load function, a problem of frame buckling can be transformed into an optimization problem. Therefore, the critical load can be found through solving the optimization problem.

先将结构离散为一个有限自由度系统；然后根据有限自由度系统平衡稳定性的能量准则和随机位移法的基本原理，建立符合能量准则的载荷函数，该函数不为零的最小值即为临界载荷，由此将稳定问题转化为无约束的多维优化问题；最后应用遗传算法求出相应于最优解的目标函数值。

The main content of this paper is to research dynamic behavior and stability of nonlinear rotorbearing system, study the numerical methods that is used to this kind of system, solve oil film forces and its Jacobian matrix at any moment, in order to offer basis for project design.

本文主要研究非线性转子—轴承系统的动力学行为和稳定性，研究用于该类系统非线性动力特性的数值方法，求解任一时刻轴承油膜力及其雅可比矩阵，为工程设计提供依据。

Differential Quadrature Method, one of numerical methods of solving boundary problem of differential equation is introduced in this paper. By using DQM, the dynamic stability of pipes conveying fluid and rectangular plates under the action of non-conservative force is studied. The main research work is as follows.

本文首先介绍了求解微分方程边值问题的一种数值方法—微分求积法，然后采用微分求积法分别对输流管道和非保守矩形薄板的稳定性问题进行了分析研究，具体有如下三方面的研究内容。

The coupling between the pressure and the velocity of numerical model was solved successfully when the SIMPLE scheme and non-interlaced grid system were applied.

本文对各气动方程的离散、计算边界条件、气动控制参数、计算方法、数值解的稳定性和收敛性等诸问题进行了探讨，提出了相应的处理办法。

Numerical analysis to Lorenz dynamical system indicates that the method converges quickly and steadly for arbitrary nonzero initial state.

对以Lorenz动力系统为主的数值计算，验证了该算法的快速性及其稳定性。

We also refer to the center manifold theorem and normal form theory, and list two calculation formulas which reflect the stability with Hop bifurcating periodic sollution, bifurcating direction.Thus provide a basis for numerical simulation calculation.

我们还用中心流形定理和规范型理论给出了确定Hopf分支周期解的稳定性，分支方向的计算公式，为数值模拟计算提供了依据。

Unfortunately, due to lack of time, the numerical error and stability analysis which is the key to developing accurate and robust algorithms are only treated superficially in the MIT undergraduate curriculum.

不幸的是，由于时间不足够，数值误差和稳定性分析是开发准确可靠的算法的关键，而它们只是很浅显地在麻省理工学院的本科课程涉及到。

Finally, a numerical example is given to show the effectiveness of the algorithm.

最后给出一个数值例子验证了这个算法的有效性和稳定性。

In this thesis we are interested in the stability of numerical methods of delaydifferential equations.

在研究泛函微分方程的数值方法时，稳定性是最重要的课题之一。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。