摘要:

AbstractA study on the dynamic response of a railway track is presented via a 3‐D formulation based on the frequency domain Boundary Element Method (BEM) and the Finite Element Method (FEM). The railway track consists of a group of surface, massive, rigid footings resting on a viscoelastic half‐space and connected by an overlaying rail structure. The BEM, employing the full‐space fundamental solutions and quadrilateral elements, is used for the simulation of the elastic half‐space while the FEM is used to model the rigid footings and the rail superstructure. The loading function consists of a set of externally applied, harmonic or transient loads. Frequency as well as transient, by way of FFT, results are presented for various modes of vibration. Various numerical studies assess the through‐the‐soil interaction of the adjacent footings, the influence of soil damping, the effect of the overlaying structure on the frequency content of the system, and the effective simulation of an infinitely long railway track by a tr

ISSN:0098-8847    

DOI:10.1002/eqe.4290240902

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe sensitivity of seismic energy dissipation to ground motion and system characteristics is assessed. It is found that peak ground acceleration, peak ground velocity to acceleration (V/A), dominant period of ground excitation and effective response duration are closely correlated with the energy dissipated by a SDOF system. Ductility ratio and damping ratio have no significant influence on the energy dissipation. An energy dissipation index is proposed for measuring the damage potential of earthquake ground motion records which includes the effects of basic excitation and response characteristics contributing to the seismic energy dissipation. The proposed index is compared with several intensity measures for the set of 94 ground motion records considered in the study.

ISSN:0098-8847    

DOI:10.1002/eqe.4290240903

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractA simple analytical procedure is developed for calculating the seismic energy dissipated by a linear SDOF system under an earthquake ground excitation. The ground excitation is specified by its pseudo‐velocity spectra and effective duration whereas the SDOF system is defined by its natural period of vibration and viscous damping ratio. However, the derived relationship for the energy dissipation demand under an earthquake excitation is sensitive neither to the viscous damping ratio nor the ductility ratio when the SDOF system undergoes inelastic response. Accordingly, the proposed relationship can be employed in an energy‐based seismic design procedure for determining the required energy dissipation capacity of a structural sys

ISSN:0098-8847    

DOI:10.1002/eqe.4290240904

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractIn this paper a general methodology for the analysis of large concrete dams subjected to seismic excitation is outlined. It is valid both for gravity dams (2D representation) and arch dams (3D representation). The method allows for non‐linear material behaviour of the dam, ‘transparent fictitious boundaries’ for dealing properly with in‐coming and out‐going seismic waves, and an efficient procedure to deal with dam‐soil‐fluid interaction. The mechanical behaviour of concrete is modelled using an isotropic damage model which allows for tension and compression damage, and exhibits stiffness recovery upon load reversals. Emphasis is placed in the treatment of fluid‐structure interaction, regarding both formulation and efficiency aspects. A gravity dam and an arch dam are analysed subjected to artificially generated earthquakes of different intensities, and the results are used to study the degree of (un)saf

ISSN:0098-8847    

DOI:10.1002/eqe.4290240905

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe concept of displacement‐based design is attractive for seismic design, primarily because it places the focus of design directly on displacement demand, and hence damage, rather than on force‐reduction or behaviour factors. A procedure is presented which extends the simple concept of displacement‐based design to complex multi‐degree‐of‐freedom (MDOF) bridge structures. The procedure is based on the assumption of a displaced shape for the structure, and the subsequent reduction of the system to an equivalent single‐degree‐of‐freedom (SDOF) system. The process is shown to work well for the design of a symmetrical bridge, while suffering some shortcomings when applied to a highly irregular bridge. The topic of design‐oriented displacement response spectra is als

ISSN:0098-8847    

DOI:10.1002/eqe.4290240906

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe evaluation of the dynamic response of non‐classically damped linear structures requires the solution of an eigenproblem with complex eigenvalues and modal shapes. Since in practice only a small number of complex modes are needed, the complex eigenvalue problem is solved in the modal subspace in which the generalized damping matrix is not uncoupled by classical real modes. It follows that the evaluation of the structural response requires in both cases the determination of complex modes by numerical techniques, which are not as robust as techniques currently used for the solution of the real eigenvalue problem, and the use of complex algebra. In the present paper an unconditionally stable step‐by‐step procedure is presented for the response of non‐classically damped structures in the modal subspace without using complex quantities. The method is based on the evaluation of the fundamental operator in approximated form of the numerical procedure. In addition, the method can be easily modified to incorporate the modal superposition pseudo‐static correct

ISSN:0098-8847    

DOI:10.1002/eqe.4290240907

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290240908

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290240909

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290240910

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290240911

出版商:John Wiley&Sons, Ltd    

年代:1995

数据来源: WILEY