摘要:

AbstractA non‐parametric identification technique is presented for chain‐like multidegree‐of‐freedom non‐linear dynamic systems. The method uses information about the state variables of non‐linear systems to express the system characteristics in terms of two‐dimensional orthogonal functions. The technique is applied to a model of a steel frame that has been extensively investigated both analytically and experimentally. The method can be used with deterministic or random excitation to identify dynamic systems with arbitrary non‐linearities, including those with hysteretic characteristics. It is also shown that the method is easy to implement and needs much less computer time and storage requirements compared to the Wiener‐kernel approach. The method is shown to have low sensitivity to the effects of additive noise in the

ISSN:0098-8847    

DOI:10.1002/eqe.4290100102

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractIn previous studies of train‐bridge interactions, impact percentages for member forces have been obtained by use of a pin‐connected truss model and for both member forces and moments by use of a rigid joint truss model. The purpose of this study is three‐fold: (a) to investigate if improved results can be obtained by use of semirigid connections at the ends of the floor beams and stringers; (b) to develop partial bridge models, for studying impacts and the range of forces and moments in members subjected to fatigue; (c) to employ a partial bridge model to study the influences of various factors on the impact factors and stress ranges of the various members and connections of the truss bridge. Descriptions of the bridge and vehicle models and the associated equations of motion are briefly stated, and results from the various bridge models are com

ISSN:0098-8847    

DOI:10.1002/eqe.4290100103

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractA procedure is described to compute the lateral and rotational floor response spectra of an asymmetric reactor building structure without a time history analysis. The spectral values obtained by filtering the prescribed ground motion first through the structure and the resulting lateral‐rotational motions through simple oscillators are equal to the maximum lateral‐rotational responses of the structure developed when the order of filtration is reversed. Based on the preceding concept a deterministic method is presented to construct the lateral‐rotational floor response spectra utilizing the response spectrum tech

ISSN:0098-8847    

DOI:10.1002/eqe.4290100104

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractA statistical representation of seismic liquefaction is advanced based on the postulate that pore water pressure increases are proportional to the dissipated seismic energy density. The representation, based on approximately fifty case histories, relates the pore pressure increase to earthquake magnitude, distance to centre of energy release, initial effective overburden stressand standard penetration value. The model may be used for analysis ofseismic liquefaction risk. An example analysis for the ‘South of Market Zone’ in San Francisco is carried out in relation to earthquakes on the San Andreas fa

ISSN:0098-8847    

DOI:10.1002/eqe.4290100105

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractA three‐dimensional hybrid model for the analysis of soil‐structure interaction under dynamic conditions is developed which takes advantage of the desirable features of the finite element and substructure methods and which minimizes their undesirable features. The modelling is achieved by partitioning the total soil‐structure system into a near‐field and a far‐field with a hemispherical interface. The near‐field, which consists of the structure to be analysed and a finite region of soil around it, is modelled by finite elements. The semi‐infinite far‐field is modelled by distributed impedance functions at the interface which are determined by system identification methods. Numerical results indicate that the proposed model makes possible realistic and economical assessment of three‐dimensional soil‐structure interaction for both surface and

ISSN:0098-8847    

DOI:10.1002/eqe.4290100106

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractThe linear response of idealized dam cross‐sections to harmonic horizontal or vertical ground motion is presented for a range of the important system parameters characterizing the properties of the dam, foundation rock and impounded water. Based on these frequency response functions, the separate effects of interaction between the dam and water and interaction between the dam and foundation, and the combined effects of the two sources of interaction, on dynamic response of dams are investigate

ISSN:0098-8847    

DOI:10.1002/eqe.4290100107

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractThe earthquake response behaviour of a cylindrical wine storage tank similar to many that were damaged in Livermore, California during the January 1980 earthquake was studied on the University of California shaking table. Tests of the 9.5 ft diameter by 20 ft high tank, with simulated earthquake accelerations up to 0.95g, induced buckling patterns similar to those observed after the actual earthquake. Observed peak axial compression stresses in the test tank wall were substantially higher than those assumed in typical design standards, demonstrating the need for further study of the buckling problem in tanks free to uplift during earthquake excitation.

ISSN:0098-8847    

DOI:10.1002/eqe.4290100108

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractAs part of fundamental research on seismic energy sources, a series of experiments was made to improve the field procedures for producing SH waves by using the so‐called plank‐striking method and also to develop more adequate techniques to generate high‐energy shear waves. Based on the results obtained, a flexible impact device which is similar to a slingshot was made to apply a relatively strong impulse at the surface of the ground. This shear wave generator was demonstrated to have desired features in its low cost operation, easy repeatability, high reproducibility and relatively large output strength. Such a shear source, therefore, provides a useful means of evaluating dynamic characteristics of the foundation soils accurately and economically which can play an important role in current earthquake engine

ISSN:0098-8847    

DOI:10.1002/eqe.4290100109

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractThe interaction between a soil layer and an end bearing pile in vertical vibration induced through the frictional interface is theoretically investigated. The pile is assumed to be vertical and elastic, whereas the soil is considered as a linear visco‐elastic layer with hysteretic damping. Slip between the pile and the soil is allowed to occur along the frictional interface, in which the hysteretic frictional stress is linearized to permit modal decomposition. Approximate solutions of the pile and the soil for steady‐harmonic loads are obtained in closed form by composing the wave modes of the layer. The displacement amplitudes of the pile and the soil, the critical slip force, the stiffness of the pile head, and the modal stiffness contribution of the soil to the pile are evaluated numerically with respect to the ratio of applied force level to the slip stress level and the slenderness ratio, at various frequenc

ISSN:0098-8847    

DOI:10.1002/eqe.4290100110

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY

摘要:

AbstractA regression analysis was made on 277 acceleration response spectra computed from Japanese accelerograms by subdividing the data into discrete categories. Five magnitude and distance categories, and four ground condition categories were used. The maximum absolute acceleration amplitude is predicted as a product of three factors, each representing a weighting factor for magnitude, distance and ground condition category at each of the 18 response spectrum periods from 0·1 s to 4 s at a damping value of 5 per cent of critical. A method was then developed to evaluate seismic hazard in terms of acceleration response spectrum by using the prediction model and the seismicity data, and it was applied to obtain seismic macro‐zoning maps of Japan which are dependent on the natural period of a structure. The results of the analysis indicated that a single seismic zoning map may not be sufficient to cover a variety of structures with a wide range of periods because the expected spectral shape differs according to the seismicity of the ar

ISSN:0098-8847    

DOI:10.1002/eqe.4290100111

出版商:John Wiley&Sons, Ltd    

年代:1982

数据来源: WILEY