摘要:

AbstractEarthquake excitation not only has evident randomness but also has strong fuzziness owing to the uncertainties in the definition of earthquake intensity and site soil classification. In this paper, the seismic ground motion is simulated as a stationary filtered white noise with fuzzy parameters, an analytical procedure is proposed to analyse the fuzzy random vibration of multi‐degree‐of‐freedom (MDOF) hysteretic systems, and the covariance matrix of the fuzzy random responses is derived by the equivalent linearization technique. Finally, some numerical results for a two‐storey shear hysteretic frame are presented to demonstrate the validity and effectiveness of the procedure p

ISSN:0098-8847    

DOI:10.1002/eqe.4290150502

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThe accuracy of the new equations for long frame‐type structures, derived by Kerr and Zarembski, and extended recently by Kerr and Accorsi also to dynamic analyses, is investigated. At first, the natural frequencies of a tall frame‐type structure, with twenty floors, are determined using the new equations, and then they are compared with the corresponding results calculated using the finite element method and the common shear‐building analysis. The found agreement with the finite element analysis is close.To check further the accuracy of the new equations, small scale models are tested on a shake table. The natural frequencies recorded in the tests are then compared with those determined from the new equations, for a wide range of geometrical parameters. The agreement with the test data is good.The presented study indicates that the new equations are well suited for analyzing the dynamic response of tall frame‐type str

ISSN:0098-8847    

DOI:10.1002/eqe.4290150503

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractClosed‐form expressions are obtained to calculate the approximate complex eigenvalues and eigenvectors of a system composed of a non‐classically damped primary structure and a single degree of freedom oscillator. The expressions are obtained through a systematic second order perturbation analysis of a transformed eigenvalue problem of the combined system. The possibility of tuning between the structure and equipment is considered. The dynamic properties of the combined system are derived in terms of the complex eigenvalues and eigenvectors of the supporting structure and the frequency, mass and damping ratio of the equipment. Examples demonstrating the accuracy of the expressions for the eigenvalues and eigenvectors are presented. These eigenproperties are used for generation of floor response spectra for non‐classically damped structures to incorporate the dynamic interaction effects between the structure and equi

ISSN:0098-8847    

DOI:10.1002/eqe.4290150504

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractA numerical method of analysis is presented for the determination of the steady‐state vertical vibration of rigid foundations with arbitrary three‐dimensional geometries resting on the surface of a layered soil medium. The method utilizes the flexibility concept applied to steady‐state periodic problems and it is solved in the frequency domain. The accuracy of the method is verified by comparison with several published solutions for massless, smooth rigid rectangular foundations on a homogeneous, isotropic elastic half‐space. Parametric solutions are presented to study the dynamic behaviour of massless, smooth rigid rectangular foundations on a homogeneous, elastic

ISSN:0098-8847    

DOI:10.1002/eqe.4290150505

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper presents random vibrations of the Baltic drilling platform subjected to water waves and wind loads. The platform structure is discretized by the finite element method. Linear beam or truss elements can be used. The structure parameters (i.e. mass, damping and stiffness) are assumed as deterministic. Soil is modelled as an elastic half‐space that possesses deterministic or random parameters. Soil–structure interaction is idealized as a system of spring–dashpot elements connecting the structure and subsoil. The parameters of these elements can be random or deterministic. The sea surface is described by the one‐dimensional wave spectrum that was proposed by Striekalov and Massel24for inland seas. It is suitable for the Baltic Sea. The wind velocity is described by the well‐known Davenport spectrum. The water and wind loads are treated as stationary ergodic processes. Gaussian distributions and zero means of these processes are assumed. In addition to this, waves and wind loads are considered as independent. Such an assumption corresponds to the situation when the storm sea is fully developed. A frequency‐domain random‐vibration approach is utilized to obtain the dynamic response of the platform. The equations of motion of the problem were solved using modal reduction. The numerical calculations were made with a specially written computer program. From the results obtained, it is concluded that the wind influence on the response of the platform can be neglected. If random parameters are assumed for the subsoil, then the response of the system describes in a more realistic way the dynamic behaviour of the platform. The velocity coupling due to soil and hydrodynamical damping is negligible. This paper is a condensation of the author's Ph.D. thesis presented at the Technical University of Gdańs

ISSN:0098-8847    

DOI:10.1002/eqe.4290150506

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractAttention is first focused on the probability distributions of the exceedance rates of given earthquake magnitudes when the generation process is idealized as Poisson. But data on significant disturbances are always scarce. Local‐seismicity assessment is hence guided by information from tectonically similar areas, but ordinarily the guidance is intuitive. Bayesian statistics constitute the tool to do this rationally. Two more alternatives are presented and illustrated here. The approach is extended to a generating process that includes the Poisson as a special cas

ISSN:0098-8847    

DOI:10.1002/eqe.4290150507

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractIn the present study, the question of inelasticp–Δ effects is examined from the perspective of inelastic spectral ordinates. Inelastic acceleration response spectra are generated using a model which includes the effects of gravity; for each spectrum the ductility factor and the gravity load level (characterized by the stability coefficient) are held constant. Amplification spectra are generated by taking the ratio between spectra with and without gravity effects. The results are analysed statistically and a formula for the amplification factor as a function of the relevant parameters is obtained. Special care is taken to present a formulation that is simple and useful in the context of practical earthquake engineering design.Some currently usedp–Δ amplification factors are discussed in the light of the results obt

ISSN:0098-8847    

DOI:10.1002/eqe.4290150508

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290150509

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290150510

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290150511

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY