تحلیل طیفی سازه ها با استفاده از تئوری موجک و مدت زمان حرکت قوی زمین

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده فنی مهندسی،دانشگاه شهرکرد

2 دانشیار گروه مهندسی عمران، دانشکدة فنی مهندسی، دانشگاه شهرکرد

چکیده

در این مقاله برای اولین بار به بررسی همزمان تبدیل موجک و مفهوم زمان حرکت قوی زمین در تحلیل طیفی سازه‌ها استفاده شده است. هدف از این پژوهش بهینه‌سازی محاسبات مربوط به طیف زلزله ی اصلی می‌باشد. بر این اساس زلزله ی مورد نظر تا 5 مرحله فیلتر می‌شود. در هرمرحله از فیلتر دو موج تقریبات و جزئیات حاصل می‌شود. به دلیل این که موج تقریبات به زلزله‌ی اصلی نزدیک تراست از این موج برای محاسبات استفاده می‌شود. به همین دلیل در هرمرحله از فیلترتعدادرکوردهای زلزله نصف مرحله‌ی قبل می‌شود. پس از آن براساس مفهوم مدت زمان حرکت قوی زمین در موج زلزله‌ی اصلی و موج‌های به دست آمده از فیلترموجکی، قسمتی از زلزله که دارای جنبش قوی است جدا می‌شود. پس در این مرحله نیز یک تقلیل در رکوردهای زلزله انجام گرفت. پس از آن طیف هریک از موج های حاصل شده رسم می‌شود. در انتها یک سازه ی دوبعدی10طبقه و یک سازه ی سه بعدی5طبقه باهریک از طیف‌های به دست آمده از دو مفهوم تبدیل موجکی گسسته و مدت زمان جنبش نیرومند زمین تحلیل می‌شود. نتایج نشان می‌دهد که با تقلیل محاسبات مربوط به طیف به اندازه‌ی بیش از 93 درصد می‌توان سازه را با خطایی کمتر از 4 درصد تحلیل نمود. می‌توان گفت که تکنیک ارائه شده یکی ازبهترین تکنیک‌های ارائه شده دربهینه سازی محاسبات مربوط به تحلیل طیفی سازه‌ها است.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Spectral analysis of structures using wavelet theory and concept of time of strong ground motion

نویسندگان [English]

  • noorollah majidi 1
  • Ali Heidari 2
1 Faculty of Engineering, Shahrekord University
2 Associate Professor of Civil Engineering, Shahrekord University
چکیده [English]

In this paper, for the first time, the simultaneous analysis of wavelet transformation and the concept of the time of strong ground motion in spectral analysis of structures has been used. The purpose of this research is to optimize the calculations related to the main earthquake spectrum. Accordingly, the earthquake is filtered up to 5 steps. At each stage, the filter provides two waves of approximations and details. Because the wave of approximations is closer to the original earthquake, this wave is used for calculations. For this reason, at each stage of the filter, the number of earthquake records is half past. Subsequently, based on the concept of the time of strong ground motion in the wave of the main earthquake and the wave obtained from the wavelet filter, part of the earthquake that has a strong movement is separated. So at this stage, there was a reduction in earthquake records. After that, the spectrum of each of the waveforms is plotted. At the end, a two-dimensional 10-story structure and a three-dimensional five-story structure with each spectrum obtained from two discrete wavelet concepts and the duration of a strong ground motion are analyzed. The results show that by reducing the computation of the spectrum by more than 93%, the structure can be analyzed with an error less than 4%. It can be said that the proposed technique is one of the best techniques presented in the optimization of calculations related to spectral analysis of structures.

کلیدواژه‌ها [English]

  • Spectral analysis: Dynamic analysis : Discrete wavelet : Earthquake :Time of strong ground motion

مراجع

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نشریه مهندسی عمران امیرکبیر
دوره 52، شماره 7
مهر 1399
صفحه 1685-1704

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