بررسی آزمایشگاهی تاثیر بارگذاری دینامیکی بر پنل های مسلح مستطیلی ساخته شده با کامپوزیت سیمانی خود تراکم الیافی و ورق های مشبک

نوع مقاله : علمی - پژوهشی

نویسندگان

1 استادیار، گروه عمران، دانشگاه لرستان، خرم آباد، ایران

2 دانشجوی کارشناسی ارشد، دانشگاه لرستان، خرم آّباد، ایران

چکیده

ماهیت بارگذاری های ضربه ای و دینامیکی به دلیل اعمال نیروی زیاد در چند میلی ثانیه با بارگذاری استاتیکی متفاوت می باشد. میزان جذب و استهلاک انرژی در مواد کامپوزیتی، معیاری مناسب به منظور بررسی عملکرد آنها در برابر بارهای ضربه ای می باشد. جاذب های انرژی به طور وسیعی در صنعت مورد استفاده قرار می گیرد. از طرفی استفاده از کامپوزیت های توانمند خود تراکم به دلیل ویژگی های منحصر به فرد آن، مورد توجه محققین قرار گرفته است. مقاومت فشاری و کششی بالا، مقاومت خمشی بالا موجب توجه بیش از پیش محققین به این نوع از کامپوزیت های سیمانی شده است. در این تحقیق بصورت یک کار جامع آزمایشگاهی با استفاده از 4 طرح اختلاط پایه، 64 پنل کامپوزیتی مستطیلی در دو گروه به ابعاد 100 در 100 میلیمتر با چهار ضخامت 30، 45، 60 و 75 میلیمتر ساخته و تحت بار ضربه ای دینامیکی تست شده اند. بر روی هر چهار طرح اختلاط ساخته شده، آزمایش های مقاومت فشاری، کششی و خمشی انجام گردید. از الیاف فولادی با درصد های 0، 25/0، 5/0 و 75/0 با طول 25 میلی‌متر به منظور ساخت کامپوزیت های سیمانی استفاده شد. دستگاه آزمایش ضربه از چکشی به وزن 180 کیلوگرم و توان 7500 ژول در این تحقیق استفاده شده است. نمونه ها با ارتفاع سقوط 600 میلیمتر، تحت بار گذاری دینامیکی قرار گرفته اند. مطابق با نتایج آزمایشگاهی مشاهده گردید که استفاده ترکیبی از الیاف و ورق های مشبک فولادی به صورت ترکیبی، موجب افزایش میزان جذب انرژی به طور قابل ملاحظه ای شد. همچنین نیروی پیک اولیه نیز افزایش یافت و همچنین طول لهیدگی و تغییر شکل نمونه کاهش یافت.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental study of the effect of dynamic loading on rectangular armed panels made of self-compacting composite fiber and lattice sheets

نویسندگان [English]

  • Ahmad Dalvand 1
  • Hossein Hatami 1
  • Arezo Seyedi Chegini 2
1 Assistant professor, faculty of engineering, lorestan university,khorramabad, iran
2 Lorestan University
چکیده [English]

The nature of dynamic loading is different due to the high force in a few milliseconds with static loading. The amount of energy absorption and energy loss in composite materials is a suitable measurement to evaluate the performance against impact loads. On the other hand, the use of self-compacting composites due to its unique properties has attracted the attention of researchers. High compressive and tensile strength, high flexural strength, has attracted more attention from researchers to this kind of cement composites. In this research, in the form of a comprehensive laboratory work, using four basement mixing designs, 64 rectangular composite panels were constructed in two groups of 100*100 mm with four thicknesses of 30, 45, 60 and 75 mm and tested under dynamic loading. Tensile and flexural strength tests were made on all four mixing designs. Steel fibers with percentages of 0, 0.25, 0.5 and 0.75 with length of 25 mm were used for the construction of cement composites. The drop hammer test machine with weighs 180 kg and the power of 7500 J is used. According to laboratory results, the combined use of steel and fiber reinforced steel sheets increased the energy absorption considerably. Also, the initial peak force increased and the deformation length decreased.

کلیدواژه‌ها [English]

  • Cement composite
  • Compressive strength
  • Micro steel fibers
  • energy absorber
  • Force-Displacement curve
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