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141.
An Incremental Response Spectrum Analysis Procedure Based on Inelastic Spectral Displacements for Multi-Mode Seismic Performance Evaluation 总被引:1,自引:0,他引:1
M. Nuray Aydinoğlu 《Bulletin of Earthquake Engineering》2003,1(1):3-36
The so-called Nonlinear Static Procedure (NSP) based on pushover analysis has been developed in the last decade as a practical
engineering tool to estimate the inelastic response quantities in the framework of performance-based seismic evaluation of
structures. However NSP suffers from a major drawback in that it is restricted with a single-mode response and therefore the
procedure can be reliably applied only to the two-dimensional response of low-rise, regular buildings. Recognizing the continuously
intensifying use of the pushover-based NSP in the engineering practice, the present paper attempts to develop a new pushover
analysis procedure to cater for the multi-mode response in a practical and theoretically consistent manner. The proposed Incremental
Response Spectrum Analysis (IRSA) procedure is based on the approximate development of the so-called modal capacity diagrams,
which are defined as the backbone curves of the modal hysteresis loops. Modal capacity diagrams are used for the estimation
of instantaneous modal inelastic spectral displacements in a piecewise linear process called pushover-history analysis. It
is illustrated through an example analysis that the proposed IRSA procedure can estimate with a reasonable accuracy the peak
inelastic response quantities of interest, such as story drift ratios and plastic hinge rotations as well as the story shears
and overturning moments. A practical version of the procedure is also developed which is based on the code-specified smooth
response spectrum and the well-known equal displacement rule.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
142.
143.
不饱和膨润土中气体渗透研究 总被引:1,自引:0,他引:1
作者对不饱和膨润土中气体渗透情况进行了研究,对实验所使用的膨润土和砂进行了密度、容重、粒重、孔隙度及含水率等特性的表征。实验所建立的气体渗透研究装置可用于测定气体渗透系数,并将其作为材料气体渗透性能的表征,实验结果表明:膨润土的孔隙度和含水率对其渗透系数有十分显著的影响。 相似文献
144.
145.
146.
S. O. Selam E. M. Esmer H. V. Şenavcı E. Bahar O. Yörükoğlu M. Yılmaz Ö. Baştürk 《Astrophysics and Space Science》2018,363(2):34
In this study, we have performed simultaneous solutions of light and radial velocity curves of two eclipsing binary systems, V566 Oph and V972 Her. We observed both systems spectroscopically with a very recently installed spectrograph on the 40 cm telescope, T40, located in Ankara University Kreiken Observatory (AUKR), for the first time. We made use of the photometric data from the Hipparcos satellite for V972 Her, while we obtained the photometric observations of V566 Oph by using the 35 cm telescope, T35, located also in our observatory campus. We derived the absolute parameters for both systems and discussed their evolutionary states. In addition to the simultaneous analysis, we have also analyzed the change in mid-eclipse times for V566 Oph, and found cyclic variations, for which we have discussed light-time effect and magnetic activity as their potential origin, superimposed on a secular change due to a mass transfer between the components of the binary. 相似文献
147.
Karin Sesetyan Mine B. Demircioglu Tamer Y. Duman Tolga Çan Senem Tekin Tuba Eroğlu Azak Özge Zülfikar Fercan 《Bulletin of Earthquake Engineering》2018,16(8):3367-3397
The seismic zoning map of Turkey that is used in connection with the national seismic design code (versions issued both in 1997 and 2007) is based on a probabilistic seismic hazard assessment study conducted more than 20 years ago (Gülkan et al. in En son verilere göre haz?rlanan Türkiye deprem bölgeleri haritas?, Report No: METU/EERC 93-1, 1993). In line with the efforts for the update of the seismic design code, the need aroused for an updated seismic hazard map, incorporating recent data and state-of-the-art methodologies and providing ground motion parameters required for the construction of the design spectra stipulated by the new Turkish Earthquake Design Code. Supported by AFAD (Disaster and Emergency Management Authority of Turkey), a project has been conducted for the country scale assessment of the seismic hazard by probabilistic methods. The present paper describes the probabilistic seismic hazard assessment study conducted in connection with this project, incorporating in an area source model, all recently compiled data on seismicity and active faulting, and using a set of recently developed ground motion prediction equations, for both active shallow crustal and subduction regimes, evaluated as adequately representing the ground motion characteristics in the region. The area sources delineated in the model are fully parameterized in terms of maximum magnitude, depth distribution, predominant strike and dip angles and mechanism of possible ruptures. Resulting ground motion distributions are quantified and presented for PGA and 5 % damped spectral accelerations at T = 0.2 and 1.0 s, associated with return periods of 475 and 2475 years. The full set of seismic hazard curves was also made available for the hazard computation sites. The second part of the study, which is based on a fault source and smoothed seismicity model is covered in Demircioglu et al. in Bull Earthq Eng, (2016). 相似文献
148.
Geomagnetism and Aeronomy - The kinetic theory is particularly suitable and convenient to calculate the collision parameters in the ionospheric medium. In this study, the mean free path (λ)... 相似文献
149.
In this study a new method is presented to determine model parameters from magnetic anomalies caused by dipping dikes. The proposed method is applied by employing only the even component of the anomaly. First, the maximum of the even component is divided to its value at any distance x in order to obtain S1. Then, theoretical even component values are computed for the minimal depth (h) and half-width (b) values. S2 is obtained by dividing their maximum to the value computed for the same distance x. A set of S2 values is calculated by slowly increasing the half-width, and h and b for the S2 closest to S1 are determined. The same procedure is repeated by increasing the depth. The determined b values are plotted against the corresponding values of h. After repeating the process and plotting curves for different distances, it is possible to determine the actual depth and half-width values. 相似文献
150.
Y?lmaz Mahmuto?lu 《Engineering Geology》2006,82(3):137-144
It is well known rock masses contain several types of weakness planes varying from micro-fissure to fault in size. The fracture frequency, degree of saturation and time are the basic rock parameters affecting its behaviour. However, in most cases, it is practically difficult to test heavily fractured rock in laboratory environment. In this study, the effects of micro cracks, strain rate and water saturation on strength are discussed using a small-scale physical experiments. It is attempted to detach the grain boundaries of coarse-grained rock specimens of the Mu?la marble by thermal treatment that would serve as a small-scale physical simulation of fractures in rock masses and enable a discussion of the variations in time dependent mechanical behaviour. An experimental study was conducted on marble specimens induced thermally by micro-cracks in different frequencies. The thermal treatment periods being 24 h in inert atmospheric condition were varied for each test specimen except categories A and G. Effective porosity increased up to 2.4% after the last thermal cycle of category F. Then conventional compression tests with different strain rates were carried out using a servo-controlled testing machine on both dry and saturated specimens. It is concluded that both lowering strain rates and increasing porosity related with thermally induced micro cracks have important effects on strength and failure path. The progressive failure entirely occurs along the grain boundaries fissured by cyclical treatment and inter-granular deformation depends upon degree of thermal influence. The small-scaled laboratory model enabled to demonstrate that parameters such as joint frequency, time and saturation have a significant effect on mechanical behaviour of rock masses. 相似文献