توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱COMPARISON OF DIFFERENT METHODS FOR SELECTION AND SCALING OF GROUND MOTION TIME HISTORIES
نویسنده(ها): ،
اطلاعات انتشار: پنجمین کنفرانس بین المللی زلزله شناسی و مهندسی زلزله، سال
تعداد صفحات: ۹
Limitations in the existing ground motion database force the scaling of real records to obtain accelerograms that are consistent with the ground motion target for structural design and evaluation. Usually the processes of selecting earthquake ground motions and their scaling to match the design spectrum are separate and distinct. Several methods of scaling time histories have been proposed. These include frequency–domain methods and time–domain methods. In the seismology and engineering communities the acceptance of the limits for legitimacy of scaling varies a lot. In this study different methods of scaling time histories are compared. A set of ground motion is selected and scaled with different methods to match the target response spectrum. Scaling factors obtained from different methods are compared. A new method for selecting and scaling records is introduced. The biases in the resulting nonlinear structural response, introduced by scaling of earthquake records, are compared in different scaling methods.<\div>

۲ESTIMATION OF INCREMENTAL DYNAMIC ANALYSIS RESULTS USING ENDURANCE TIME METHOD
نویسنده(ها): ،
اطلاعات انتشار: پنجمین کنفرانس بین المللی زلزله شناسی و مهندسی زلزله، سال
تعداد صفحات: ۸
Endurance Time (ET) method is a relatively new Performance–Based Earthquake Engineering method for structural evaluation and design. In this method, the structure is subjected to a gradually intensifying accelerogram(s) and its performance is assessed based on the maximum time duration that it can meet the specified performance objectives. Using several single degree of freedom oscillators with different periods and damping and nonlinear characteristics and also several multistory frames from low–rise to mid–height buildings, it is shown that ET can estimate results of the Incremental Dynamic Analysis (IDA) with acceptable accuracy. Spectral acceleration has been considered as the intensity measure. While the IDA would require several nonlinear dynamic analyses under multiple suitably scaled ground motion records, the ET can practically estimate the seismic behavior of simple to complex systems only by few nonlinear time history analyses. The results show that this method has the benefits of time history analysis and simplicity of the nonlinear static methods and can potentially be a useful tool for evaluating
and designing seismic resistant structures.<\div>

۳A DAMAGE SPECTRA APPROACH TO THE DESIGN OF STEEL MOMENT FRAMES
نویسنده(ها): ،
اطلاعات انتشار: پنجمین کنفرانس بین المللی زلزله شناسی و مهندسی زلزله، سال
تعداد صفحات: ۶
Past engineering experiences have shown that the popular design methods have some weaknesses when considering the performance based design concepts. In order to overcome these weaknesses various guidelines have been proposed. Although the Performance Based Earthquake engineering is popular to reassess and rehabilitate the existing structures, it has not found its place in popular design methodologies and building codes. In this paper, by using the concepts of “damage spectra” and “performance levels” introduced in FEMA–356 guideline, some damage spectrums have been developed that can be used to define the applicable lateral load on the structure as an alternative to the response spectrums proposed by popular building codes. These damage spectrums help engineers to design structures with any required performance level. The comparison between these damage spectrums, Iran standard 2800 response spectrum and NEHRP 2000 gives a good insight to engineers. In generating these damage spectrums some assumptions have been made which are presented and discussed in detail. At last, the performance levels of some sample steel moment frames under the base earthquakes used in generating damage spectrums are assessed using nonlinear time history analysis as proposed in FEMA–356 guidelines and the results are compared with the proposed method.<\div>
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