تاثیر بار محوری قائم بر ارتعاش آزاد سازه‌های قابی متقارن با روش سیستم پیوسته

نوع مقاله: علمی - پژوهشی

نویسندگان

1 استادیار، دانشگاه محقق اردبیلی

2 دانشیار، دانشگاه صنعتی سهند

چکیده

مطالعات موجود در زمینه ارتعاش آزاد خمشی و پیچشی سازه‌های قابی معمولا بدون در نظر گرفتن اثر بار محوری انجام شده است. در این مقاله به بررسی تاثیر بار محوری بر ارتعاش آزاد خمشی- پیچشی سازه‌های قابی مسطح و سه بعدی با استفاده از روش سیستم پیوسته پرداخته شده است. در روش سیستم پیوسته که یکی از پرکاربردترین روش‌ها در تحلیل تقریبی سازه‌های ساختمانی محسوب می‌شود، سازه ساختمانی با یک عضو تیری مناسب که شامل مشخصات غالب سازه می‌باشد، جایگزین می‌شود. بر این اساس، با حل معادله دیفرانسیل حاکم بر تیر معادلی که در آن توزیع جرم و سختی یکنواخت فرض شده است، می‌توان فرکانس‌های طبیعی سازه‌های ساختمانی مذکور را محاسبه کرد. بار محوری معادل وارد شده بر تیر، بر حسب وزن کل و تعداد طبقات ساختمان محاسبه شده است. برای نشان دادن سادگی و موثر بودن حل پیشنهاد شده، یک نمونه مثال عددی نیز ارائه شده است.

کلیدواژه‌ها


عنوان مقاله [English]

The effect of axial loads on free vibration of symmetric frame structures using continuous system method

نویسندگان [English]

  • Elham Ghandi 1
  • Behzad Rafezy 2
1 Asistant professor, Faculty of Technical and Engineering, University of Mohaghegh Ardabili
2 Associate professor, Faculty of Civil Engineering, Sahand University of Technology
چکیده [English]

The free vibration of frame structures has been usually studied in literature without considering the effect of axial loads. In this paper, the continuous system method is employed to investigate this effect on the free flexural and torsional vibration of two and three dimensional symmetric frames. In the continuous system method, in approximate analysis of buildings, commonly, the structure is replaced by an equivalent beam which matches the dominant characteristics of the structure. Accordingly, the natural frequencies of the symmetric frame structures are obtained through solving the governing differential equation of the equivalent beam whose stiffness and mass are supposed to be uniformly distributed along the length. The corresponding axial load applied to the replaced beam is calculated based on the total weight and the number of stories of the building. A numerical example is presented to show the simplicity and efficiency of the proposed solution.

کلیدواژه‌ها [English]

  • Axial load
  • Continuous system method
  • Frame structures
  • Free flexural
  • Torsional vibration

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