摘要:

AbstractA Laplace domain technique to calculate non‐linear foundation uplift effects is presented. Analysis in the Laplace domain permits the modelling of the building structure more precisely by using continuous mass models. Different damping models for every single finite element of the sturcture can easily be utilized via the correspondence principle. Moreover, it is possible to use the substructure method, which permits the modelling of the soil and the building structure separately by different methods. Using, e.g. the boundary element method for the soil, the damping mechanism caused by waves travelling away from the foundation (geometric damping effects) is implicitly included. The model can be condensed to the relevant degrees of freedom of the structure. Two illustrative numerical examples demonstrate the applicability of the method presente

ISSN:0098-8847    

DOI:10.1002/eqe.4290160602

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractTo calculate the generalized scattered motion in the region of a canyon of arbitrary shape in a horizontally layered half‐space, the indirect‐boundary‐element method in the frequency domain is applied. Fictitious distributed source loads acting on the line which will form the surface of the canyon are used. The corresponding Green's functions, which are determined by a transformation to the wave‐number domain, satisfy the conditions at the interfaces of the adjacent layers including those at the free surface. The discretization with boundary elements can thus be restricted to the line which will form the surface of the canyon. By formulating a weighted residual statement, the sum of the surface tractions composed of those of the free field and of the fictitious loads averaged over each boundary element are set equal to zero.Based on vast parametric studies addressing inclined body waves and surface waves for the out‐of‐plane and in‐plane cases, the amplification patterns within and adjacent to the canyon are studied and conclusio

ISSN:0098-8847    

DOI:10.1002/eqe.4290160603

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe application of spline functions in the analysis of structural dynamics is presented in this paper. The nodal points in time discretization for determining the spline curve can be separated into two classes: thepnodal points before the current time (including current time) and theqnodal points after the current time. On thepnodal points, the structural responses were calculated at previous time steps. Theqnodal points represent the unknown structural response at future time steps which should meet the requirement of dynamic equilibrium. By a trial and error procedure, at least 16 families of spline curves with different locations ofpandqnodal points can be found to meet the requirements of unconditional stability. The accuracy of each family is dependent on the order of the spline and the locations of the nodal points. The 16 families of spline curves supply a wide range of accuracy that can be selected easily. It can be shown that the well‐known Wilson‐method and the Houbolt method are special cases of the present spline approximati

ISSN:0098-8847    

DOI:10.1002/eqe.4290160604

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe dynamic substructure method in harmonic vibration is reformulated. A method to accelerate the convergence ofD−1with respect to the number of fixed interface modes is introduced. Comparison is made with the methods of Guyan and Irons, Ritz vector, substructure synthesis and dynamic substructure. A close relation among the methods is examined. The present method can predict more global modes than the number of degrees of freedom retained. It is the most economical in operation counts among the methods for systems having many identical substructure

ISSN:0098-8847    

DOI:10.1002/eqe.4290160605

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractAseismic base isolation is increasingly being utilized to protect structures and their contents against earthquakes. The R‐FBI (Resilient‐Friction Base Isolator) bearings provide a new isolation system. The equations of motions of elastic plane structures supported on R‐FBI bearings and a procedure for their solutions are presented. The responses of a five‐storey 1/3‐scaled frame model to both horizontal components and horizontal and vertical components of six different ground motion records for fixed base and isolated base are evaluated. To estimate the prototype response, the ground motion records are time scaled by The effects of initial base displacement and non‐symmetric friction caused by small differential settlements are also considered. It is concluded that R‐FBI reduces the acceleration response considerably without inducing large base displacements or leaving large residual

ISSN:0098-8847    

DOI:10.1002/eqe.4290160606

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractSemi‐explicit iterative algorithms for time integration of large‐scale non‐linear dynamic problems are presented. They use iteratively only forward substitution which allows for the vectorial computation with both consistent and lumped mass matrices. The stability and rate of convergence of the non‐linear iterative solutions can be improved using single or multiparameter acceleration procedures. Numerical results show the stability, accuracy and efficiency of the alg

ISSN:0098-8847    

DOI:10.1002/eqe.4290160607

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractA simple analytic model is developed to describe the stiffness of non‐skew monolithic highway bridge abutments for purposes of seismic bridge analysis. The model permits an evaluation of six equivalent discrete spring stiffnesses for three translational and three rotational degrees‐of‐freedom of the abutment and includes effects of the abutment walls, pile foundations and soil. These springs can be incorporated as boundary elements in a more detailed finite element analysis of the dynamic response of the bridge superstructure. A parametric study examines a range of abutment stiffnesses for 2, 4 and 6 lane highway bridges. Application of the model to a single span bridge indicates the importance of including abutment stiffness in the determination of bridge frequencies and mode shapes in the transverse and vertical direc

ISSN:0098-8847    

DOI:10.1002/eqe.4290160608

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractAn approximate non‐linear response spectrum method for the analysis of three‐dimensional structures is presented. The non‐linear effects are taken into account by employing an equivalent linearization criterion along with inelastic spectra and geometric stiffness matrices. The linearization procedure replaces the inelastic system by an equivalent linear syste on a member‐by‐member basis and accounts for the frequency shift and change in damping. Rational procedures combining modal and spatial response maxima for three‐dimensional structures subject to multi‐component respone spectra are also discussed. The modal response spectrum predictions compare favourably with those obtained from die time‐h

ISSN:0098-8847    

DOI:10.1002/eqe.4290160609

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractThe influence of the depth and material properties of a sedimentary deposit on earthquake ground motion is examie through theoretical modelling. The strong stratification of a typical deposit is represented by a number of homogene layers of dissipative viscoelastic material. The motion is assumed to be produced by a line source. The calculations carried out by means of a recently developed theoretical technique. The near surface low velocity layers are found to has a very strong amplification effect on the ground motion at some frequencies. The widely used one dimensional approae for site effect evaluation is shown to be valid for smaller epicentral distances only. The deamplification effect of mate dissipation is shown to be extremely important in most cases.

ISSN:0098-8847    

DOI:10.1002/eqe.4290160610

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY

摘要:

AbstractAn analysis procedure for seismic wave propagation effects on straight continuous buried pipelines is proposed. It shown that ground strain due to surface waves can be substantially larger than that due to body waves. An elastic model a buried pipeline surrounded by equivalent soil springs indicates that frictional slip between the pipeline and the surrounding soil springs is likely for high ground strains.A method for estimating ground strain due to surface waves, based on data from the 1971 San Fernando earthquake, reviewed. An analysis procedure, which utilizes frictional forces near the soil‐pipeline interface, is proposed for surfae wave effects on straight buried continuous pipelines. The proposed procedure is illustrated with an exampl

ISSN:0098-8847    

DOI:10.1002/eqe.4290160611

出版商:John Wiley&Sons, Ltd    

年代:1988

数据来源: WILEY