摘要:

AbstractActive tendon control of cable‐stayed bridges subject to a vertical sinusoidal force is experimentally and analytically studied. Emphasis is placed on the effects of linear and non‐linear internal resonances on the control (due to the presence of the cable vibration). A simple cable‐supported cantilever beam is used as a model. It is found that active tendon control is very effective in vertical girder motion with small cable vibration (girder dominated motion), whereas it is not effective in vertical girder motion with large cable vibration (cable dominated motion). Analytical prediction is very satisfactory except for the latter

ISSN:0098-8847    

DOI:10.1002/eqe.4290220202

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper attempts to study the response of light equipment items attached to a multi‐storey building that may be subjected to large torsional deformations during the earthquake excitation. To account for the effect of torsion and translation, each storey of the building is modelled as two degrees of freedom (DOFs), with one DOF for translation and the other for torsion. Perturbation techniques are employed to find closed‐form expressions for the modal properties of the combined system in terms of the properties of the individual subsystems. The interaction between the equipment and building is studied for both tuned and detuned modes of vibration. Modal synthesis results obtained using the present technique based on the complete quadratic combination (CQC) method are compared with solutions obtained by other meth

ISSN:0098-8847    

DOI:10.1002/eqe.4290220203

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThis paper deals with the identification of the parameters of a smoothed hysteretic model which was proposed by Bouc and Wen with emphasis on restoring force hysteresis. The problem of estimating the parameters of this system on the basis of input‐output data, possibly noise corrupted, is considered. Through the application of various simulated time histories from the hysteretic model, a three‐stage systematic method of system identification was proposed. Four different methods of identification are arranged and conducted in this three‐stage system identification. The first stage, a sequential regressional analysis is used to identify the equivalent linear system from which elastic or inelastic response can be identified. The identified parameters can be used in the stage when the system is in elastic response. In the second stage, both time domain least‐squares method and Gauss‐Newton method are applied. The convergence of the Gauss‐Newton method can be guaranteed if the identified results from least‐squares method are adopted as the initial values for Gauss‐Newton method. In the third stage, the extended Kalman filtering technique is needed to identify the noise‐corrupt data. Application of this algorithm to a SDOF non‐deteriorating

ISSN:0098-8847    

DOI:10.1002/eqe.4290220204

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractAn efficient, adaptive and robust algorithm is proposed to reduce the cost of large‐scale stationary and transient random vibration analysis of structures excited by multiple partially correlated nodal and or base excitations. The cost saving is accomplished by computing integrals selectively, and yet attempting to maintain a level of accuracy desired by the analyst. Recently, proposed closed‐form solutions for fully coherent propagating band‐limited white‐noise excitation are used to rank approximately the terms in the modal covariance matrix. Terms are then evaluated starting from the most important one, and the computations are terminated in such a way that the accuracy level requested by the user is satisfied in an approximate sense. Two variations of the algorithm are proposed: the first one is more robust and is preferred, and is recommended when computing a relatively small number (hundreds) of response quantities; the second one is more efficient when computing a very large number (thousands) of response quantities. Both variations are adaptive, and consider the closeness, damping and participation of all modes explicitly, while the first method also considers the mode shapes. The efficiency and accuracy of the algorithm is investigated by using it to compute the stationary and transient seismic response of the Golden Gate suspension

ISSN:0098-8847    

DOI:10.1002/eqe.4290220205

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

摘要:

AbstractThe seismic motion in sediment‐filled valleys due to incident SH‐waves has been studied exhaustively. However, the response of such geologic structures to incident SV‐ and P‐waves has not been studied as thoroughly. The response of a 2‐D model of the valley of Caracas, Venezuela—a NS cross‐section through the Palos Grandes district—to incident plane SV‐ and P‐waves is investigated using thediscrete wave number boundary element method.It is observed that the differences in the predictions of the 1‐D and 2‐D models are more pronounced for SV‐waves than for SH‐waves, especially when SV‐waves are incident at (or near) the critical angle ic. The valley responds very strongly to the horizontally propagating P‐wave (SP‐wave) which is induced when SV‐waves, incident at the critical angle, interact with the free surface of the half‐space. However, the SP‐wave, being a wave diffracted at a boundary, is likely to be sensitive to impedance contrasts, to the presence of other interfaces in the medium, and to the topography surrounding the valley. These aspects of

ISSN:0098-8847    

DOI:10.1002/eqe.4290220206

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290220207

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY

ISSN:0098-8847    

DOI:10.1002/eqe.4290220201

出版商:John Wiley&Sons, Ltd    

年代:1993

数据来源: WILEY