阻尼法

Because the central difference method is conditional stable, the critical time step and damping were estimated by model analysis, which can guarantee the computation stability. In this paper, the mesh method was used to described the tool surface.

由于中心差分法的计算是有条件稳定，作者对确定系统临界时间步长和阻尼系数的方法进行了研究，采用模态分析理论估计临界时间步长和阻尼，保证了计算的稳定性。

In this dissertation, dynamic phasor method based on the critical damping adjustment is developed to eliminate the numerical oscillation caused by the changes of the network configuration.

分析了基于梯形法的动态相量仿真的数值振荡问题，结合现有的算法和动态相量法的特点，讨论了基于临界阻尼调整法的动态相量法。

Using this method,we discussed for generalized Burger equation with variable coefficients and linear danping,obtained its symmetry group,simliar reduced equations,infinitesimal generator and Lie algebras;In chapter 6,using the Exp-function method,the generalized solutions of combined KdV-mKdV equation with variable coefficients are discussed.

首先介绍了Lie群分析法的基本思想，其次用Lie群分析法得到了带线性阻尼项的变系数广义Burgers方程的无穷小变换、无穷小算子的李代数结构，并具体求出了带线性阻尼项的变系数广义Burger方程的群不变解和约化方程。

ABSTRACT:The half-power bandwidth method is the commonly used method at home and abroad, the authors discover that factors, such as the sampling frequency, the frequency resolution, the ratio of the sampling frequency to the signal frequency, the analyzed width and the damping ratio, make the estimated damping ratio fluctuate vastly. Mostly the result is incredible except for some conditions, the error is sometime amazing, which is not acceptable.

半功率带宽法是国内外常用的测试阻尼的方法，笔者发现半功率带宽法由于受到信号处理中的①采样频率SF②频率分辨率△f③采样频率与信号频率之比K ④采样分析的长度T和⑤阻尼比D的大小等因素的影响使得测得的阻尼比值波动很大，除少数状态是可信的外，多数状态是不稳定的，有时误差惊人，得到的测试数据不能使用，易导致错误的结论。

The operating case of current liquid dampers, in which have been used in engineering, has been investigated by analyzing the distribution of oil kinetics parameters such as pressures and flow velocities based on finite element method for design of constructer of the new MR fluid damper and its characteristic simulation.

通过分析目前工程中的轿车液力阻尼器工作原理，采用有限元法对阻尼器内部流体的工作状态进行了分析；探讨了油液在工作过程中的压力、流速及其流场分布的动力学特征，为流体阻尼器结构设计及其阻尼特性的数值模拟分析提供了理论依据。

Compared with reinforced concrete floor, steel deck possess the advantage of thin wall, light in mass, but owing to smallness of damp, weakness of dissipation of energy, comfort possibly dissatisfies applicability required. Therefore, this paper first calculates and analyses dynamic property of new style steel deck; according to single footfall curve, ascertaining hominine walking excitation; utilizing time-history analytical method, calculating peak acceleration response of floor slab under excitation, and analyzing peak acceleration response proceeding from different board stride, different damping ratio as well as different profile.

相对于钢筋混凝土楼板而言，虽然钢承板具有壁薄、质轻的优势，但由于阻尼小、耗能差，其舒适度可能会不满足适用性的要求，为此本文首先计算和分析了新型钢承板的动力特性；根据单步落足曲线确定了人的行走激励；利用时程分析法，计算了楼板在行走激励下的最大加速度响应，并对不同板跨、不同阻尼比以及不同板型下的最大加速度响应进行了分析，结果表明这三种因素，尤其阻尼比和板型对于加速度响应的影响较大。

In this paper, the dynamic characteristics of a beam with viscous damping layers are studied. For convenience to analyze by transfer matrix method, the concept of equivalent dissipated energy is utilized to transform the damping layers to be uniformly soloed into the beam body without changing thesis damping effect.

中文摘要本文是以梁含有黏滞阻尼作动态特性研究，为了方便作分析，本文利用传递矩阵法作分析，再以消散能等效原理，将阻尼均匀融入在主梁其不改变阻尼效益。

A model of self-controlled synchronous motor (including double armature winding synchronous motor) is developed which takes account of damper winding according to its actual structure. The damper winding is represented by two sets of loop on each axis based on multi-loop method and bar currents may be calculated.

本文首先建立了包括参数计算在内的自控式同步电动机（包括双电枢绕组自控式同步电动机）的数学模型，该模型采用多回路法处理阻尼绕组，便于计算阻尼条的电流，可以比较准确地分析阻尼绕组对电机运行性能的影响。

It effectively solves the problem of contact mechanics between burden granules. The dynamic data structure that is a linked list is built to save and delete the varying data in simulation calculation process. Therefore, the distinct element method simulation model of charging bell-less top blast furnace is established in view of the distinct element method model of blast furnace burden granular.

本文首先对离散单元法的基本原理和数值计算方法进行了系统研究，针对高炉炉料颗粒介质特点，对离散单元法进行了相应改进，建立了高炉炉料颗粒运动的离散单元法基本数学模型，推导出了相应的高炉炉料颗粒离散单元法数值计算基本参数的计算公式，例如阻尼、刚度、时步等，并确定了合理的数值模拟参数值。

Simulations of forced response of mistuned bladed disks with non-linear dry friction damping were performed.

摘要基于谐波平衡法，提出一种可用于分析含有非线性摩擦阻尼叶盘振动响应的多谐波法，对含有非线性干摩擦阻尼的失谐叶盘系统的受迫响应进行仿真计算。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。