Yin-bo QIAN Xian-mei RAO Rui-z     

hong WANG Ying-jian 《大地构造与成矿学》2007,(3)

the multiple phase screen method,could numerically simulate the turbulence effects,thermal blooming and their mutual effects for laser atmospheric propagation. Four types of propagation paths and ten kinds of optical turbulence profiles are also included into the program, which make it possible to simulate the propagating process and the atmospheric effects for laser beam with a circular or rectangular aperture under currently available conditions.Moreover,the beam propagating process can be visualized simultaneously by utilizing open graphics library (OpenGL).With the friendly user interface  相似文献   

地震作用下上部结构刚度改变对基桩受力的影响     

蒋晓东  李建光  杨小卫 《世界地震工程》2007,23(3):108-112

结合典型工程实例，采用在土体侧向边界节点处用弹簧并联阻尼器来进行模拟，在平面应变单元和桩体梁单元连接处用约束方程的方法进行节点耦合、满足连续条件，选择桩、土、荷载参数，用整体有限元方法进行桩－土－结构相互作用体系的地震反应分析。重点讨论了三种不同的上部结构刚度对桩基地震内力的影响，得到了在水平地震荷载作用下上部结构刚度的增大将增大桩基的内力及水平位移，且桩顶及桩身处于第一个软硬土层交界面处的截面的内力尤为突出等结论。关键词：上部结构刚度改变；桩－土－结构相互作用；弹性－阻尼边界；地震反应分析  相似文献   

钢管混凝土动力性能研究新进展   总被引：2，自引：0，他引：2  

卢辉 《世界地震工程》2007,23(4):119-128

简要介绍了国内外近年来在钢管混凝土包括钢管混凝土构件、钢管混凝土梁柱节点及钢管混凝土结构动力性能的部分研究工作。对研究成果在试验研究、计算方法和计算理论等方面进行回顾、分析和综合评述。并对钢管混凝土动力性能的进一步研究进行了展望。  相似文献   

Re‐shaping hysteretic behaviour—spectral analysis and design equations for semi‐active structures     

Geoffrey W. Rodgers  John B. Mander  J. Geoffrey Chase  Kerry J. Mulligan  Bruce L. Deam  Athol Carr 《地震工程与结构动力学》2007,36(1):77-100

Semi‐active dampers offer significant capability to reduce dynamic wind and seismic structural response. A novel resetable device with independent valve control laws that enables semi‐active re‐shaping of the overall structural hysteretic behaviour has been recently developed, and a one‐fifth scale prototype experimentally validated. This research statistically analyses three methods of re‐shaping structural hysteretic dynamics in a performance‐based seismic design context. Displacement, structural force, and total base‐shear response reduction factor spectra are obtained for suites of ground motions from the SAC project. Results indicate that the reduction factors are suite invariant. Resisting all motion adds damping in all four quadrants and showed 40–60% reductions in the structural force and displacement at the cost of a 20–60% increase in total base‐shear. Resisting only motion away from equilibrium adds damping in quadrants 1 and 3, and provides reductions of 20–40%, with a 20–50% increase in total base‐shear. However, only resisting motion towards equilibrium adds damping in quadrants 2 and 4 only, for which the structural responses and total base‐shear are reduced 20–40%. The spectral analysis results are used to create empirical reduction factor equations suitable for use in performance based design methods, creating an avenue for designing these devices into structural applications. Overall, the reductions in both response and base‐shear indicate the potential appeal of this semi‐active hysteresis sculpting approach for seismic retrofit applications—largely due to the reduction of the structural force and overturning demands on the foundation system. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Seismic behaviour of self‐centring braced frame buildings with reusable hysteretic damping brace     

Songye Zhu  Yunfeng Zhang 《地震工程与结构动力学》2007,36(10):1329-1346

This paper presents the seismic behaviour of a concentrically braced frame system with self‐centring capability, in which a special type of bracing element termed reusable hysteretic damping brace (RHDB) is used. The RHDB is a passive energy dissipation device with its core energy‐dissipating component made of superelastic Nitinol wires. Compared with conventional bracing in steel structures, RHDB has a few prominent performance characteristics: damage free under frequent and design basis earthquakes in earthquake prone areas; minimal residual drifts due to the self‐centring capability of RHDB frame; and ability to survive several strong earthquakes without the need for repair or replacement. This paper also includes a brief discussion of the RHDB's mechanical configuration and analytical model for RHDB. The seismic performance study of RHDB frame was carried out through a non‐linear time history analysis of 3‐storey and 6‐storey RHDB frame buildings subjected to two suites of 20 earthquake ground motions. The analysis results were compared with buckling‐restrained brace (BRB) frames. This study shows that RHDB frame has a potential to outperform BRB frames by eliminating the residual drift problem. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Performance of a real‐time pseudodynamic test system considering nonlinear structural response     

Rae‐Young Jung  P. Benson Shing  Eric Stauffer  Bradford Thoen 《地震工程与结构动力学》2007,36(12):1785-1809

This paper presents the implementation details of a real‐time pseudodynamic test system that adopts an implicit time integration scheme. The basic configuration of the system is presented. Physical tests were conducted to evaluate the performance of the system and validate a theoretical system model that incorporates the dynamics and nonlinearity of a test structure and servo‐hydraulic actuators, control algorithm, actuator delay compensation methods, and the flexibility of an actuator reaction system. The robustness and accuracy of the computational scheme under displacement control errors and severe structural softening are examined with numerical simulations using the model. Different delay compensation schemes have been implemented and compared. One of the schemes also compensates for the deformation of an actuator reaction system. It has been shown that the test method is able to attain a good performance in terms of numerical stability and accuracy. However, it has been shown that test results obtained with this method can underestimate the inelastic displacement drift when severe strain softening develops in a test structure. This can be attributed to the fact that the numerical damping effect introduced by convergence errors becomes more significant as a structure softens. In a real‐time test, a significant portion of the convergence errors is caused by the time delay in actuator response. Hence, a softening structure demands higher precision in displacement control. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Donald Ralph Bowes     

Bernard Elgey Leake 《Proceedings of the Geologists' Association. Geologists' Association》2007,118(1):5-10

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Assessment of the seismic non-linear behavior of ductile wall structures due to synthetic earthquakes     

Philippe Schwab  Pierino Lestuzzi 《Bulletin of Earthquake Engineering》2007,5(1):67-84

In this paper, different methods for generating synthetic earthquakes are compared in terms of related non-linear seismic response of ductile structures. The objective of the investigation is to formulate recommendations for the use of synthetic earthquakes for reliable seismic analysis. The comparison is focused on the accuracy of the reproduction of the characteristics of the structural non-linear response due to recorded earthquakes. First the investigations are carried out for non-linear single-degree-of-freedom systems. Later, the results are validated for a set of realistic buildings modelled as multi-degree-of-freedom systems. Various options of the classical stationary simulation procedure of SIMQKE and a non-stationary simulation procedure proposed by Sabetta and Pugliese are examined and compared. The adopted methodology uses a set of recorded earthquakes as a reference. Hundred synthetic accelerograms are generated for each examined simulation option with the condition that the related elastic responses are similar to those of the reference set. The non-linear single-degree-of-freedom systems are defined using six recognized hysteretic models and four levels of increasing non-linearity. The non-linear responses computed for the reference set and the studied simulation options are then statistically compared in terms of displacement ductility and energy. The results show that the implementation of the classical stationary procedure always leads to a significant underestimation of the ductility demand and a significant overestimation of the energy demand. By contrast, non-stationary time histories produce much better results. The results with the multi-degree-of-freedom systems are shown to confirm these conclusions.  相似文献   

Finite-difference Euler Deconvolution Algorithm Applied to the Interpretation of Magnetic Data from Northern Bulgaria     

Daniela?GerovskaEmail author  Petar?Stavrev  Marcos J.?Araúzo-Bravo 《Pure and Applied Geophysics》2005,162(3):591-608

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Experimental remolding on the caprock’s 3D strain field of the Indosinian-Yanshanian epoch in Tongling deposit concentrating area     

DENG Jun  HUANG Dinghua  WANG Qingfei  WAN Li  SUN Zhongshi  YANG Liqiang & GAO Bangfei . State Key Laboratory of Geological Processes  Mineral Resources  China University of Geosciences  Beijing  China  . Faculty of Earth Sciences  China University of Geosciences  Wuhan  China  . Department of Earth Sciences  Jilin University  Changchun  China 《中国科学D辑(英文版)》2005,(7)

~~Experimental remolding on the caprock’s 3D strain field of the Indosinian-Yanshanian epoch in Tongling deposit concentrating area1.Chang,Y.F.,Liu,X.P.,Wu,Y.C,The Cu,Fe Metallogenic Belt in the Middle-Lower Reaches of Yangtze River(in Chinese with English abstract),Beijing:Geological Publishing House,1991,1-379. 2.Yin,H.F.,Wu,S.B.,Du,Y.S.,South China is the part of multi-islands and multi-oceans system of Tethys,Earth Sciences(in Chinese),1999,24(1):1-12. 3.Wu,G G,Zha…  相似文献