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Roles of soil-structure interaction and damping in base-isolated structures built on numerous soil layers overlying a half-space

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Earthquake Engineering and Engineering Vibration 2016年第2期15卷 387-400页

作者： c.S.Tsai c.I.Hsueh H.c.Su Department of civil Engineering Feng Chia University Graduate Institute of civil & Hydraulic Engineering Feng Chia University Department of Water Resources Engineering and conservation Feng Chia University

This study examines the roles of soil-structure interaction （SSI）, higher modes, and damping in a base-isolated structure built on multiple layers of soil overlying a half space. closed-form solutions for the entire system, including a superstructure, seismic isolator, and numerous soil layers overlying a half-space, were obtained. The formulations obtained in this study simply in terms of well-known frequencies and mechanical impedance ratios can explicitly interpret the dynamic behavior of a base-isolated structure interacting with multiple soil layers overlying a half-space. The key factors influencing the performance of the isolation system are the damping ratio of the isolator and the ratio of the natural frequency of the fixed-base structure to that of the isolated structure by assuming that the superstructure moves as a rigid body. This study reveals that higher damping in the base isolator is unfavorable to higher mode responses that usually dominate the responses of the superstructure and that the damping mechanism plays an important role in transmitting energy in addition to absorbing energy. It is also concluded that it is possible to design a soft soil layer as an isolation system for isolating vibration energy.

关键词： base isolation seismic isolation soil-structure interaction closed- form solution higher-mode effects soilstratum passive control damping effects

Equivalent series system to model a multiple friction pendulum system with numerous sliding interfaces for seismic analyses

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Earthquake Engineering and Engineering Vibration 2014年第1期13卷 85-99页

作者： c.S.Tsai H.c.Su T.c.chiang Department of civil Engineering Feng Chia University Department of Water Resources Engineering and conservation Feng Chia University Earthquake Proof Systems Inc.

current structural analysis software programs offer few if any applicable device-specifi c hysteresis rules or nonlinear elements to simulate the precise mechanical behavior of a multiple friction pendulum system(MFPS) with numerous sliding *** on the concept of subsystems,an equivalent series system that adopts existing nonlinear elements with parameters systematically calculated and mathematically proven through rigorous derivations is *** aim is to simulate the characteristics of sliding motions for an MFPS isolation system with numerous concave sliding interfaces without prior knowledge of detailed information on the mobilized forces at various sliding *** MFPS with numerous concave sliding interfaces and one articulated or rigid slider located between these interfaces is divided into two subsystems: the fi rst represents the concave sliding interfaces above the slider,and the second represents those below the *** equivalent series system for the entire system is then obtained by connecting those for each subsystem in *** equivalent series system is validated by comparing numerical results for an MFPS with four sliding interfaces obtained from the proposed method with those from a previous study by Fenz and ***,these numerical results demonstrate that an MFPS isolator with numerous concave sliding interfaces,which may have any number of sliding interfaces,is a good isolation device to protect structures from earthquake damage through appropriate designs with controllable mechanisms.

关键词： seismic isolation base isolation earthquake engineering multiple friction pendulum system structural control mathematical modeling equivalent series system

Nonlinear dynamic analysis of multi-base seismically isolated structures with uplift potentialⅡ:verification examples

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Earthquake Engineering and Engineering Vibration 2010年第1期9卷 83-91页

作者： Panayiotis c.Roussis Panos c.Tsopelas Michael c.constantinou Department of civil and Environmental Engineering University of Cyprus Department of civil Engineering University of Thessaly Department of civil Structural and Environmental EngineeringUniversity at BuffaloState University of New York

The work presented in this paper serves as numerical verification of the analytical model developed in the companion paper for nonlinear dynamic analysis of multi-base seismically isolated structures. To this end, two numerical examples have been analyzed using the computational algorithm incorporated into program 3D-BASIS-ME-MB, developed on the basis of the newly-formulated analytical model. The first example concerns a seven-story model structure that was tested on the earthquake simulator at the University at Buflhlo and was also used as a verification example for program SAP2000. The second example concerns a two-tower, multi-story structure with a split-level seismic-isolation system. For purposes of verification, key results produced by 3D-BASIS-ME-MB are compared to experimental results, or results obtained from other structural/finite element programs. In both examples, the analyzed structure is excited under conditions of bearing uplift, thus yielding a case of much interest in verifying the capabilities of the developed analysis tool.

关键词： seismic isolation nonlinear dynamic analysis uplift verification multiple superstructures/bases

Nonlinear dynamic analysis of multi-base seismically isolated structures with uplift potential Ⅰ:formulation

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Earthquake Engineering and Engineering Vibration 2009年第3期8卷 421-431页

作者： Panos c.Tsopelas Panayiotis c.Roussis Michael c.constantinou Department of civil Engineering University of ThessalyVolosGreece Department of civil and Environmental Engineering University of CyprusNicosiaCyprus Department of civill Structural and Environmental EngineeringUniversity at BuffaloState University of New YorkBuffaloNYUSA

The complexity of modem seismically isolated structures requires the analysis of the structural, system and the isolation system in its entirety and the ability to capture potential discontinuous phenomena such as isolator uplift and their effects on the superstructures and the isolation hardware. In this paper, an analytical model is developed and a computational algorithm is formulated to analyze complex seismically isolated superstructures even when undergoing highly-nonlinear phenomena such as uplift. The computational model has the capability of modeling various types of isolation devices with strong nonlinearities, analyzing multiple superstructures （up to five separate superstructures） on multiple bases （up to five bases）, and capturing the effects of lateral loads on bearing axial forces, including bearing uplift. The model developed herein has been utilized to form the software platform 3D-BASIS-ME-MB, which provides the practicing engineering community with a versatile tool for analysis and design of complex structures with modem isolation systems.

关键词： friction-pendulum isolator, seismic isolation nonlinear dynamic analysis uplift multiple superstructures multiple bases

Bending waves of a rectangular piezoelectric laminated beam

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Acta Mechanica Sinica 2020年第5期36卷 1099-1108,I0003页

作者： c.P.Wei c.X.Xue Department of Mechanics School of ScienceNorth University of ChinaTaiyuan 030051China

A simple nonlinear model is proposed in this paper to study the bending wave in a rectangular piezoelectric laminated beam of infinite *** on the constitutive relations for transversely isotropic piezoelectric materials and isotropic elastic materials,combined with some electric conditions,we derive the bending wave equation in a long rectangular piezoelectric laminated beam by using energy *** nonlinearity considered is geometrically associated with the nonlinear normal strain in the longitudinal beam *** shock-wave solution,solitary-wave solution and other exact solutions of the bending wave equation are obtained by the extended F-expansion *** by using the reductive perturbation method we derive the nonlinear Schrodinger(NLS)equation,further more,the bright and dark solitons are *** those soliton solutions,and some parameters derived by the process of solving soliton solutions,some conclusions are drawn by numerical analysis with some fixed conditions.

关键词： Bending wave Rectangular piezoelectric laminated beam Extended F-expansion method Nonlinear Schrodingereruation

Demonstration of full-parallax three-dimensional holographic display on commercial 4 K flat-panel displayer

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chinese Optics Letters 2016年第1期14卷 26-30页

作者： Frank c. Fan Sam choi c. c. Jiang AFc Technology co. Ltd. Shenzhen 518104 China

A novel method for a full-parallax three-dimensional （3D） holographic display by means of a lens array and a holographic functional screen is proposed. The process of acquisition, coding, restoration, and display is described in detail. It provides an efficient way to transfer the two-dimensional redundant information for human vision to the identifiable 3D display for human eyes. A holo-video system based on a commercial 4 K fiat-panel displayer is demonstrated as the result.

关键词： Geometrical optics Holography

ZnO@Porous Media,Their PL and Laser Effect

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Journal of Materials Science & Technology 2008年第4期24卷 495-511页

作者： c.Bouvy Laboratory of Inorganic Materials chemistry The University of Namur(FUNDP)61 rue de BruxellesB-5000 NamurBelgium

Optoelectronic nanocomposites are a new class of materials, which exhibit very interesting and particular properties and attract a growing attention due to their potential applications in information storage and optoelectronic devices. Zinc oxide, ZnO, is one of the most interesting binary semiconductor （3.37 eV） with very important optical properties, which can be used in the fields such as short wavelength lasers, blue light emitting diodes, UV detectors, gas sensors, etc. This paper reviews the very recent progress in the prepa- ration of silica-based ZnO nanocomposites. After an introduction reviewing the theoretical background, the article will begin with a survey of the optical properties and the quantum size effect （QSE） of ZnO/SiO2 nanocomposites prepared by the inclusion of ZnO nanoclusters inside silica mesoporous materials. The second part will focus on one of the most interesting properties of ZnO/SiO2 nanocomposites, which is the random lasing effect after one- and two-photon excitation. The final part will deal with the introduction of ZnO nanoparticles inside microporous zeolites and the observation of QSE. For comparison, the photoluminescence （PL） and QSE properties of ZnS nanoparticles occluded in mesoporous media are also described. New potential applications will be discussed since short-wavelength devices are required by industry to design, for instance, new information storage supports and biolabelling devices.

关键词： ZnO nanoparticles Microporous and mesoporous materials Quantum size effect Random lasing effect

Phase Homogeneity and crystal Structure of Sb_(88)Te_(12) Synthesized by Melt-quench Method

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Acta Metallurgica Sinica(English Letters) 2013年第4期26卷 441-446页

作者： c.Rangasami Department of Physics Erode Sengunthar Engineering College

Phase homogeneity and crystal structure of SbsaTe12 alloy synthesized by melt-quench method have been analyzed using X-ray diffraction （XRD） and Raman spectroscopy. Rietveld refinement of crystal structure of Sb8sTe12 has revealed the formation of SbsTe3 and Sb phases respectively with 11R and A7 structures （space group is R3m）. Phase fractions of the phases SbsTe3 and Sb have been determined to be 44.44% and 55.56% respectively. Raman spectrum of SbssTe12 has showed a highest intensity peak at 156 cm-1 and another peak at 151.1 cm-1, which correspond to Alg modes of SbsTe3 and element Sb, respectively. Analysis of Raman spectrum has substantiated the results obtained from structure refinement regarding the presence of two different phases.

关键词： SbssTe12 alloy Melt-quench method XRD Rietveld refinement Raman spectroscopy Multiphase formation

POSITRON LIFETIME STUDY OF THERMALLY INDUcED MIcROSTRUcTURAL cHANGES IN NISTARI SILK FIBER

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chinese Journal of Polymer Science 2003年第3期21卷 325-332页

作者： c.Ranganathaiah Department of Studies in Physics University of Mysore Manasagangotri Mysore-570 006 India

Positron lifetime measurements have been made in natural polymer-Nistari silk fibers as a function of isochronalannealing temperature in the range of 27℃ to 280℃. The variations in the positron results indicate the structural changesoccurring in the Nistari silk fibers and determine the glass transition temperature as 170℃. Activation energies weremeasured separately for the crystalline and amorphous regions indicating the versatility of the technique. These values areclose to the N--H bond dissociation energy, suggesting N--H bond dissociation as the most probable process occurringduring thermal treatment As an extension of the positron results, the molecular weight of the Nistari silk fibers wasdetermined to be 10.7×10~5 based on free volume, which lies within the range suggested for the silk fibers. There seems to bean indication that cross-linking changes the spiral structure of cotton fibers to network type. However, this needs to be validated by other techniques.

关键词： Nistari silk fiber Positronium Free volume Molecular weight Activation energy