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1.
低硬度橡胶隔震支座各种相关性及老化徐变特性   总被引:4,自引:1,他引:4  
作者系统地对低硬度橡胶隔震支座的材料和力学性能进行了试验研究。研究使用的低硬度橡胶隔震支座分18种规格,总计近30个大直径隔震支座。研究内容涉及低硬度橡胶隔震支座的基本力学性能;温度、压力、剪切变形、老化和徐变等相关性;压缩界限,屈曲及极限剪切变形等界限性能以及橡胶材料性能和隔震工程应用等方面。本文主要介绍低硬度橡胶隔震支座的压力、剪切变形、温度对支座刚度、阻尼等力学性能的影响,同时还对隔震支座的老化及徐变特性进行了试验研究,确定低硬度橡胶使用60年后的力学性能变化率。文中同时提出了低硬度橡胶支座的温度修正方程,并提出了隔震结构地震反应分析时支座刚度和屈服荷载变化的取值范围。  相似文献   

2.
简要叙述运用P波初动资料确定地震震源机制(断层面解)的原理与方法,并以图解法为例,详细阐述相关的物理概念及求地震震源机制解的具体步骤,以适应具有不同专业背景(例如:地震学、地球物理学、地质学、大地测量学、工程地震学、灾害科学、管理科学)的不同读者(例如:学生、教师、管理人员)的不同需求(例如:了解、学习、应用).  相似文献   

3.
主要介绍各种地震定位方法,概述各种地震定位方法的基本原理,重点介绍Geiger的经典方法以及在此基础上建立的各种线性方法:单一地震事件定位法与多个地震事件定位法以及对每一种地震定位方法的应用情况,尤其是国内的应用情况做了总结;同时指出各种方法的特点,并进行相应的比较.  相似文献   

4.
本研究系统地对低硬度橡胶隔震支座的材料及力学性能进行了试验研究。研究用低硬度橡胶天然及铅芯橡胶隔震支座18种规格总计近30个大直径隔震支座。研究内容涉及低硬度橡胶隔震支座的基本力学性能,温度、压力、剪切变形、老化及徐变等相关性能,压缩界限、拉伸界限、极限剪切变形等界限性能和屈曲特性,以及橡胶材料性能和隔震工程应用等方面。本文主要介绍低硬度橡胶天然及铅芯隔震支座的压缩、拉伸、剪切等界限性能和屈曲应力与剪切应变的相关特性,文中提出了基于刚度因子建立的橡胶支座的界限压缩和界限拉伸应力评价方程,同时还给出了剪切变形状态下的屈曲应力评价方法。  相似文献   

5.
本文利用尺度分析理论详尽地论述了旋转海洋中各类运动的特性及其相应的控制方程组,指出现实海洋中可能存在五种大尺度运动,并讨论了存在于这种运动中流场和质量场的适应过程,针对不同类型的运动分别分析了升降流的性质以及层化和摩擦对升降流的影响,估计了地球旋转对海水可压缩性的影响以及非静力平衡在各类海洋运动中的作用。  相似文献   

6.
The paper presents the first three natural frequencies and the corresponding mode shapes for fixed-base multistorey buildings which can be idealized as an equivalent planar coupled shear wall connected in series to an equivalent frame. The coupled wall is modelled as a continuum of uniform properties and the frame as a uniform shear beam, the connection between the two elements being taken as continuous. Solutions are obtained by treating the structure as a lumped parameter system with twenty equidistant discrete masses having only translational inertia. The relevant flexibility matrix is, however, generated from the exact solution of the governing differential equation for the continuum subjected to point loading. The results are presented for various combinations of the three non-dimensional parameters which are sufficient to describe all the geometric and material properties of the system. The mode shapes are presented in terms of the first three normal modes of a uniform slender cantilever. The non-dimensional base shears required for the response spectrum analysis of buildings of the type under consideration are also given for the three modes and for the various combinations of the three non-dimensional parameters mentioned above. The use of the results is illustrated by an example.  相似文献   

7.
Examples of the development of monitoring systems are considered for the case of local historical natural–technical systems of various classification levels. The authors’ scheme of classification of local HNTSs is given. The classification is aimed to systematize the diverse data on various HNTSs to form a single interrelated system basing on common principal features. Monitoring systems of local HNTSs of the Borodino Battlefield, Old Ryazan City, and Rostov Kremlin are used as examples to demonstrate their relevancy for solving problems of the complex of protection measures.  相似文献   

8.
本文利用尺度分析理论详尽地论述了旋转海洋中各类运动的特性及其相应的控制方程组,指出现实海洋中可能存在五种大尺度运动,并讨论了存在于这种运动中流场和质量场的适应过程,针对不同类型的运动分别分析了升降流的性质以及层化和摩擦对升降流的影响,估计了地球旋转对海水可压缩性的影响以及非静力平衡在各类海洋运动中的作用。  相似文献   

9.
10.
声波在两种多孔介质界面上的反射和透射   总被引:11,自引:1,他引:11       下载免费PDF全文
本文导出了声波在两种多孔介质界面上反射、透射的一般计算公式.作为例子,数值计算了P1波入射于界面时,P1、P2和S波的反射、透射系数与声波频率、入射角等量之间的关系.结果表明,各种模式波的反射、透射系数与入射角、多孔介质性质有关,在Biot特征频率附近与频率有关,并用界面两侧的法向能流相等验证了结果的正确性.若把多孔介质当作均匀固体处理,将会得到显著不同的结果.  相似文献   

11.
Theoretical broadside resistivity profiles over an outcropping dyke of infinite depth extent with three Wenner configurations (namely Alpha, Beta and Gamma), Schlumberger, and two-electrode configurations of various electrode spacings and for various reflection factors are presented. The broadside profiles qualitatively indicate that the shape of the anomaly is invariant with the electrode configurations. The various electrode configurations can be arranged in decreasing order of magnitude of anomalies as Beta Wenner, Alpha Wenner, Schlumberger, Gamma Wenner, and two-electrode. The broadside Wenner profiles also show larger anomalies compared to those in inline profiles.  相似文献   

12.
本文导出了声波在两种多孔介质界面上反射、透射的一般计算公式.作为例子,数值计算了P1波入射于界面时,P1、P2和S波的反射、透射系数与声波频率、入射角等量之间的关系.结果表明,各种模式波的反射、透射系数与入射角、多孔介质性质有关,在Biot特征频率附近与频率有关,并用界面两侧的法向能流相等验证了结果的正确性.若把多孔介质当作均匀固体处理,将会得到显著不同的结果.  相似文献   

13.
Two models, one with two small islands in a relatively narrow channel between two larger land masses and the other with an island near an irregular coast, are investigated with a view to assessing the importance of small-scale features. The perturbation of a uniform alternating geomagnetic field of various frequencies is studied by a numerical technique in which the inhomogeneous models are represented by cells of different conductivity within a three-dimensional mesh. The results are presented as contour plots of the amplitudes of the various field components over the surface of the conducting region, as well as by selected profiles of the field component amplitudes and phases. The channeling of currents around the higher resistivity island structures is apparent in the results. The effects of the small-scale structure of the coastline are pronounced in the model, and indicate that considerable care needs to be taken in selecting sites for experiments and in interpreting the results.  相似文献   

14.
现有强震记录常规处理程度中采用的插值、积分、微分运算方法计算简单、省时,但在某些情况下,不能确保所要求的计算精度,针对这一问题,本文假定强震记录是理想的有限长记录并满足采定理,在此基础上提出了对强震记录进行“精确”插值,积分和微分运算以及权函数的概念,并推导建立了相应的计算公式,理论和算例分析表明:(1)本文算法中使用的插值,积分和微分运算权函数均具有不变和快速收敛的性质;(2)只需要少量的权系数,本文算法就能获得足够的计算精度;(3)选取足够多的权系数,本文算法能以任意精度副近真实的精确解序列,(4)本文算法可以成为强震数据处理和相关结构动力分析的基础。  相似文献   

15.
上游参数空间的激波连接   总被引:2,自引:1,他引:2       下载免费PDF全文
本文分析各类激波特别是中间激波的特性与上游阿尔文数、激波角和气压-磁压比的关系,阐明各类激波在上游参数空间的连接方式.主要结论是:当上游阿尔文波速大于声速时,慢激波和快激波可通过三种基本方式相互连接;当上游阿尔文波速小于声速时,激波连接只限于慢激波和中间激波之间.这些结论有助于进一步探讨混合激波的结构和演化规津.  相似文献   

16.
本文分析各类激波特别是中间激波的特性与上游阿尔文数、激波角和气压-磁压比的关系,阐明各类激波在上游参数空间的连接方式.主要结论是:当上游阿尔文波速大于声速时,慢激波和快激波可通过三种基本方式相互连接;当上游阿尔文波速小于声速时,激波连接只限于慢激波和中间激波之间.这些结论有助于进一步探讨混合激波的结构和演化规津.  相似文献   

17.
The linear magnetoconvection in the rotating uniformly as well as non-uniformly stratified horizontal layer with azimuthal magnetic field is investigated for the various mechanical and electrical boundary conditions and especially, for various values of Roberts number. The developed diffusive perturbations (modes) are strongly influenced not only by the mentioned properties of boundaries but also by complicated coupling of viscous, thermal and magnetic diffusive processes. The mean electromotive force produced by developed hydromagnetic instabilities is also investigated to determine the hydromagnetic processes which are appropriate for -effect. The presented paper is an unification of hitherto published results of the authors and gives a short survey of many developments of corresponding model by Soward (1979).  相似文献   

18.
Modal properties of tuned mass damper (TMD)-structure two-degree-of-freedom (2DOF) linear systems are studied employing a perturbation technique. Using the perturbation solutions, formulas relevant to designing the TMD for various types of loading are obtained; they are expressed as a function of mass ratio, tuning ratio, damping ratio of the TMD and damping ratio of the structure. Equivalent additional dampings of the structure due to the TMD are derived for random and harmonic forces. Matched expressions of equivalent damping, which are valid for detuned, i.e. non-optimal, conditions are also presented. The stability boundary of TMD-structure systems subject to linear self-excited forces is derived in a closed form. Using the perturbation solutions, procedures for optimizing the TMD parameters for various types of loading are explained and the optimal values are derived. The formulas obtained in this study can be used with good accuracy for mass ratios less than 0.02.  相似文献   

19.
The use of Schlumberger and dipole arrays for crustal-scale resistivity soundings is considered. Advantages and disadvantages of the two methods are described. The depth to which resistivity may be determined from field measurements is discussed as well as the determination from the sounding curves of various parameters associated with layered structure. The interpretation of experimental data using reference curves as well as two approaches used in computer assisted interpretation are discussed.  相似文献   

20.
Zinc remediation of aqueous streams is of special concern due to its highly toxic and persistent nature. Conventional treatment technologies for the removal of zinc are not economical and further generate huge quantity of toxic chemical sludge. Biosorption is emerging as a potential alternative to the existing conventional technologies for the removal of metal ions from aqueous solutions. Mechanisms involved in the biosorption process include chemisorption, complexation, adsorption–complexation on surface and pores, ion exchange, microprecipitation, heavy metal hydroxide condensation onto the bio surface, and surface adsorption. Biosorption largely depends on parameters such as pH, the initial metal ion concentration, biomass concentration, presence of various competitive metal ions in solution, and to a limited extent on temperature. Biosorption using biomass such as agricultural wastes, industrial residues, municipal solid waste, biosolids, food processing waste, aquatic plants, animal wastes, etc., is regarded as a cost‐effective technique for the treatment of high volume and low concentration complex wastewaters containing zinc metal. Very few reviews are available where readers can get an overview of the sorption capacities of agro based biomasses used for zinc remediation together with the traditional remediation methods. The purpose of this review article is to provide the scattered available information on various aspects of utilization of the agro based biomasses for zinc metal ions removal. An extensive table summarizes the sorption capacities of various adsorbents. These biosorbents can be modified using various methods for better efficiency and multiple reuses to enhance their applicability at industrial scale. We have incorporated most of the valuable available literature on zinc removal from waste water using agro based biomasses in this review.  相似文献   

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