ترسیم دیاگرام‌های فشار- ضربه برای ستون‌های بتن مسلح دارای بار محوری بااستفاده از روش تک‌درجه آزادی معادل

مهندسی عمران فردوسی

مقاله 8، دوره 31، شماره 3 - شماره پیاپی 23، مرداد 1397، صفحه 93-107   

نوع مقاله: یادداشت پژوهشی

شناسه دیجیتال (DOI): 10.22067/civil.v32i1.57788

نویسندگان

محمد اسماعیل نیا عمران^* ؛ سمیه ملایی

دانشگاه کردستان

چکیده

در این مقاله رفتار لنگر- انحنای ستون­ بتن بااستفاده از روش اجزای محدود تعیین می‌شود و به‌عنوان یک رویکرد تک­درجه آزادی (SDOF) برمبنای تئوری اولر- برنولی معرفی می­شود تا پاسخ دینامیکی ستون بتن مسلح تحت بارگذاری جانبی انفجار تخمین زده شود. در مدل SDOF  اثرات لنگر ثانویه (P-δ) و اثرات نرخ کرنش به‌صورت گام‌به‌گام در محاسبات تغییرشکل ستون بتن مسلح تحت انفجار وارد شده‌است. به‌منظور صحت­سنجی، نتایج حاصل از مدل SDOF با نتایج مدل اجزای محدود در نرم­افزار OPENSEES و همچنین نتایج یک تست عملی انفجار مقایسه شده‌است. سپس، از مدل SDOF معرفی‌شده برای ترسیم دیاگرام فشار- ضربه­ در ستون بتن مسلح، با درنظر گرفتن بار محوری ثابت در آن، استفاده شده‌است. مطابق با نتایج حاصل، در حالت انفجار متوسط تا دور (Z>1 kg/m1/3)، روش SDOF معرفی‌شده علی­رغم سادگی و زمان کم برای انجام محاسبات، دارای نتایج با دقت کافی می‌باشد و قابل اعتماد است.

کلیدواژه‌ها

بارگذاری انفجار؛ روش تک درجه آزادی معادل؛ دیاگرام فشار- ضربه؛ ستون بتن مسلح

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