摘要:

AbstractThe influence of insulating a structure with a soft first storey (horizontally elastic or elastoplastic or horizontally and vertically elastic) is investigated for horizontally propagating waves. A comprehensive parametric study for a simple structure excited by SH‐ and R‐waves is performed. A reactor building is examined for a horizontally propagating historic earthquake. Compared to a conventional structure, travelling‐wave effects become more important for R‐waves in a structure with a horizontal soft first storey. For SH‐waves, the opposit

ISSN:0098-8847    

DOI:10.1002/eqe.4290090102

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractThe efficiency of a transient dynamic plate bending solution procedure based on the use of Mindlin plate elements with a central difference time stepping scheme is improved by suitably modifying the rotatory inertia terms in the diagonalized mass matrix.

ISSN:0098-8847    

DOI:10.1002/eqe.4290090103

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractA novel method has been proposed for the finite element solution of the steady‐state scalar wave equation in three‐dimensions. In this the governing equation and the prescribed boundary conditions in the physical space are transformed into a spherical polar space in which the radial direction is logarithmically condensed; the physical problem domain is also mapped into the new space. The transformed equation is then solved in the mapped domain using conventional finite elements. Because physical dimensions of the problem are logarithmically condensed in the proposed spherical polar space, the method is particularly suitable for solving truly three‐dimensional problems in which the aspect ratio(s) is large or very large.A number of illustrative examples considered show that the proposed method is capable of a high degree of accuracy, achieved efficiently and economically. A hybrid scheme has also been proposed for dealing with awkward‐shaped

ISSN:0098-8847    

DOI:10.1002/eqe.4290090104

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractMost offshore platforms are supported on long and large‐diameter piles with variable wall‐thickness along the length, and soil properties varying with depth. The design and analyses of these piles are made by modelling the soil‐pile system with a beam‐on‐Winkler foundation. Therefore, evaluation of appropriate soil‐pile springs for use in such analyses is a matter of concern. Fundamental characteristics of dynamic lateral load‐deflection relationships for piles were studied analytically considering the soil‐pile‐structure interaction under seismic loading conditions. The soil layer was assumed homogeneous, linearly elastic with hysteretic type material damping, and overlying a rigid base. A superstructure with multi‐degrees of freedom was supported by a single vertical pile hinged at the rigid base.Parametric studies were carried out to identify the influence of the system parameters on the behaviour of the dynamic lateral load‐deflection relationships of piles. The lateral load‐deflection relationships vary considerably with depth and are influenced not only by the dynamic properties of soil but also by the structural properties of a pile and loading conditions. These lateral load‐deflection relationships can be used to define the soil‐pile springs for the seismic response analysis of a soil‐pile‐structure system, and the results can be extended to problems with soil profiles

ISSN:0098-8847    

DOI:10.1002/eqe.4290090105

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

摘要:

AbstractIn this paper seismically induced overturning effects in stiffened building frames are studied by examining the response of two structures: a 20‐storey ‘core wall’ reinforced concrete frame and a 10‐storey steel braced frame. The excitations utilized in the study are the 1971 Pacoima Dam S16E Record and the 1940 El Centro N‐S Record magnified by a factor of two. Non‐linear effects of the following types are considered: plastic hinging of beams and columns, yielding and/or buckling of bracing members and transient uplift of portions of the structures from the foundation. In particular, comparisions are made between response with unlimited base overturning capacity assumed and response with dead‐weight overturning resistance only. Providing dead‐weight overturning resistance only is shown to significantly reduce seismic load levels, with relatively little or no loss in drift control. Ductility demand in these stiffened frames is shown to be limited, when transient uplift is allowed, to the link beams connecting stiffened and unstiffened portions of

ISSN:0098-8847    

DOI:10.1002/eqe.4290090106

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290090107

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290090108

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290090110

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290090101

出版商:John Wiley&Sons, Ltd    

年代:1981

数据来源: WILEY