مقايسه رفتار غير خطي ديوارهاي برشي فولادي با ورق هاي صاف و موج دار

Compared to Non-Linear Behavior of Flat and Corrugated Sheet Steel Shear Walls

چكيده- ديوارهاي برشي فولادي(ssw)براي مقابله با نيروهاي جانبي زلزله و باد در ساختمان ها به ويژه در ساختمان هاي بلند در سه دهه اخير مورد توجه قرار گرفته است. اين پديده نوين كه در جهان به سرعت رو به گسترش است در ساخت ساختمان هاي جديد و همچنين تقويت ساختمان هاي موجود به ويژه در كشورهاي زلزله خيزي مانند آمريكا و ژاپن به كار گرفته شده است. از نظر اجرايي، سيستمي بسيار ساده است و پيچيدگي خاصي در آن وجود ندارد. از مزاياي اصلي اين ديوارها مي توان به شكل پذيري بالا و مقاومت زياد آن ها اشاره كرد. در اين مقاله رفتار ديوار برشي فولادي ساخته شده از ورق هاي صاف و موج دار بررسي و و دوره اي آن ها تحت بارگذاري چرخه اي ارزيابي شده است. طبق بررسي هاي انجام شده در اين مقاله، push-over منحني هاي ديوارهاي برشي فولادي موج دار شكل پذيري پايين تري نسبت به ديوارهاي برشي با ورق صاف دارد. در اين پژوهش همچنين معلوم شد با اين كه در جابجايي هاي پايين، ورق موج دار مقاومت بالايي دارد؛ ولي رفتار ديوار برشي با ورق صاف نسبت به ديوار برشي موج دار پايدارتر است. جذب انرژي ديوار برشي صاف نسبت به ديوار برشي موج دار بيشتر است. بنابراين استفاده از ديوار برشي با ورق صاف در مناطق با خطر زلزله خيزي زياد توصيه مي شود.

Steel shear walls has been noticed against wind and earthquake lateral loads about high buildings in the last three decades. This modern phenomenon is growing rapidly worldwide so that system have been employed highly in construction of new buildings and seismic upgrading of existing buildings in some countries such as USA and JAPAN. That is a very simple system from viewpoint of implementing and there isn’t particular complexity. High strength and ductility are main advantages of these systems. Current paper has investigated comparatively behavior of steel shear walls made of smooth and corrugated sheets. Also the paper has assessed push-over curves and cyclic binding. According to this result of the research, corrugated steel shear walls have lower ductility than smooth shear walls. The research also founded that despite the high strength of corrugated sheets in low displacement, behavior of flat shear walls is more stable than corrugated shear walls. On the other hand flat steel shear walls attract energy more than corrugated shear walls. Therefore using of flat shear walls is recommended in high seismic regions. In this research, 18 samples of flat steel shear walls and corrugated shear walls were modulated. In all models, panels height were 3 m and panels span were 3, 4 and 5 m. the thickness of sheets in the samples were 3, 4 and 5mm. According to results of the research: 1- Corrugated sheets are unstable and unpredictable in high thinness. In the low displacements occurs a mutation state, so it distinguishes the corrugated and flat shear walls behavior. 2- At low displacement, a corrugated sheet bears greater load than a flat sheet. 3- In a constant thickness for thinner corrugated sheets is increased the mutation rate and its behavior becomes more non-uniform. 4- Despite of the fact, pynchyng phenomenon appears in all samples, but all samples behavior is stable and significant energy attraction is observed.