Pall型摩擦阻尼支撑内力计算方法   总被引：3，自引：0，他引：3  

吴斌  张纪刚  欧进萍 《世界地震工程》2004,20(2):6-11

从Pall摩擦阻尼器四连杆机构的几何非线性变形特征出发，分析框架位移、支撑刚度、阻尼器摩擦力、阻尼器大小、支撑倾角、支撑屈曲力等对一种改进的Pall摩擦阻尼器-T形芯板摩擦阻尼器支撑的受力特点，拟合出可供设计人员使用的实用计算公式。  相似文献   

Nonlinear Dynamic Response of HDRB and Hybrid HDRB-Friction Sliders Base Isolation Systems     

Franco?Braga  Marco?Faggella  Rosario?Gigliotti  Michelangelo?LaterzaEmail author 《Bulletin of Earthquake Engineering》2005,3(3):333-353

The isolation systems are usually made of rubber bearings that are sometimes coupled in hybrid combination with frictional devices; this is the case of an in-site experimental campaign, performed on a base isolated apartment building in Rapolla (south of Italy). Several dropout tests at initial displacements up to 17cm allowed to obtain in-site information on the true dynamic response of the isolation system (building and isolators). The tests carried out allow a comparison between the free vibration responses of a building, isolated by using a 28 HDRB isolation system only, or an HDRB-Friction Sliders Hybrid one. The paper highlights the main differences of the response in the superstructure (the structure over the isolation system) obtained by using only HDRB isolation system, or the Hybrid one (HDRB and Friction Sliders in parallel system). Analysis and comparisons of experimental data, show the influence of nonlinearities on structural higher modes amplification, especially observed by using the higher nonlinear Hybrid isolation system. Tests results confirm that, in the case of a regular superstructure, like the Rapolla building, the isolation system nonlinearities influence the structural response.  相似文献   

非线性参数平差的一个新途径   总被引：10，自引：0，他引：10  

刘国林  郭金运 《测绘工程》1998,7(2):28-34

在分析顾及一阶偏导致的非线性参数平差的近似直接解法与迭代解法基础上,提出顾及到二阶偏导数的非线性参数平差的一种新的计算公式。由于非线性度量曲率立体阵的引入,使得平差计算公式表达简洁,而且便于非线性平差本质的分析。最终算例分析说明该方法的有效性及实用性。  相似文献   

一个考虑二氧化碳的非线性气侯模式   总被引：1，自引：0，他引：1  

郑祖光  刘莉红 《热带气象学报》2000,16(3)

建立一个包含年平均二氧化碳含量［ＣＯ_２］、下垫面温度、边界层气温以及云量的零维气候模式,用于研究ＣＯ_２对气候的影响。结果表明,该模式能模拟出现代气候态以及［ＣＯ_２］变化的趋势。进而用与该模式相应的现代气候平衡态的偏差方程,考察了在ＣＯ_２的作用下,气候系统由定常态到周期态再到混沌态的演变过程。  相似文献   

基于改进型前馈神经网络的流域产流预报模型的研究   总被引：4，自引：0，他引：4  

王栋  曹升乐 《水文》1999,(6):8-11

在分析流域产流机制、影响因素和现行产流计算方法的基础上,首次取前期影响雨量、主产流历时、全过程面平均雨量和４个代表雨强计７个因子作为神经网络输入,直接以流域产流深作为神经网络输出,并针对传统ＢＰ算法的固有缺陷,采用混合ＧＮ－ＢＦＧＳ算法训练网络。实例验证了所建模型及算法的有效性和可行性。还对神经网络隐层单位数等进行了初步研究。  相似文献   

局域积能振荡模型在地震研究中的应用   总被引：1，自引：0，他引：1  

郑熙铭  肖家鑫 《国际地震动态》1995,(12):10-14

采用非均匀介质中能量的非线性积累过程，模拟唐山７．８级和大同６．１级地震的前兆场演化，发现能量主要聚集在介质参数发生改变的地区，而且能量的增强呈现聚集－恢复－聚集的过程，说明地震孕育过程中出现的各种前兆特征，与地壳内能量的非线性聚集有关。  相似文献   

一类热流问题解的存在性     

管平  李刚 《南京气象学院学报》1997,20(2):199-204

热敏半导体器件中电位与温度满足的方程组，是一个椭圆－抛物耦合组，并带有混合边界条件。利用不动点定理可证明该问题解的存在性。  相似文献   

CONTOUR DYNAMICS FOR VORTEX MOTION INFLUENCED BY THE CORIOLIS FORCE^*          下载免费PDF全文

Luo Zhexian 《Acta Meteorologica Sinica》1994,8(1):60-71

The computational formulae are given for single-contour constant-value vortex motion influenced by the Coriolis force in the framework of contour dynamics,by which four numerical computations are performed,the result exhibiting their validity.  相似文献   

求解非线性有限元方程的弧长法及在工程稳定分析中的应用   总被引：1，自引：0，他引：1  

刘国明  卓家寿 《岩土力学》1993,14(4):57-67

本文讨论了求解非线性有限元方程弧长法的基本原理及具体实施,并应用于压杆及滑块的稳定性分析。由于弧长法具有确定并通过结构临界应力状态的临界荷载值,因此可以应用于工程稳定性分析。算例表明,弧长法确定的临界荷载值是令人满意的。  相似文献   

Numerical algorithm for the dynamic analysis of base-isolated structures with dry friction     

S. Dimova  V. Georgiev 《Natural Hazards》1992,6(1):71-86

This paper deals with the techniques for solving ordinary differential equations with essential nonlinearity arising from the representation of frictional force by the sign function of the relative velocity. This problem is connected with dynamic behavior studies of base-isolated structures with dry friction devices.Mathematical evidence is presented concerning the inaccuracies of the solution which are connected with the representation of the frictional force by the sign function. An approximation of this sign model is made on the basis of the appropriate linearization of a small part of the frictional force function. A numerical algorithm for the dynamic analysis of base-isolated structures with dry friction is proposed. Numerical tests are carried out for establishing the exactness of the proposed techniques. The obtained results prove the accuracy of the techniques.  相似文献