بررسي عددي رفتار برشگيرهاي نوين در دال‌هاي مركب با عرشه فولادي

Numerical analysis of novel shear connectors in composite slabs with steel deck

دال هاي مركب با عرشه فولادي، يك سيستم سازه اي نسبتا نوين است كه استفاده از آن‌ها در سال هاي اخير به دليل مزيت هاي خوب اين نوع سقف ها افزايش يافته است. براي اينكه اين سيستم سازه اي به طور مركب و يكپارچه عمل كند، از اتصال دهنده ها (برشگير) استفاده مي شود. هم اكنون برشگيرهاي متداولي كه در سازه ها استفاده مي شود از نوع گلميخ‌هاي جوشي است كه خطرات محيط زيستي فراواني دارد و همچنين اگر سازه به پايان عمر مفيد طراحي خود برسد، تعمير اين نوع اتصالات هزينه هاي زياد و آسيب هاي محيط زيستي فراواني دارد. در اين تحقيق با جايگزيني اين اتصالات جوشي با اتصالات نوين پيچي معرفي شده، سعي در ارتقاي اين اتصالات داشتيم و به وسيله ارتقاي مدل آزمايشگاهي كه قبلا در دانشگاه برادفورد در اين باره انجام شده و شبيه سازي آن به وسيله نرم افزار اجزا محدود ABAQUS، نتايج جديدي درباره اين نوع از برشگيرهاي پيچي حاصل گرديد. در اين مقاله اثر پارامترهاي متنوعي از قبيل: مقاومت بتن، طول و قطر مختلف برشگير‌ها و نوع گوناگون ورق عرشه فولادي بر روي رفتار اين اتصال‌دهنده‌ها مورد بررسي قرار گرفت.

composite slabs with Steel deck is a relatively new structural system which has been increasingly applied in recent years due to the numerous advantages brought about by these ceilings. Shear connections are used to have these structural systems performed compositely and integrally. As of now, conventional shear connections typically incorporated into structures are of welded type. This type of connection is difficult and costly to repair when design life time of the structure comes to end, while producing a great deal of environmental pollution. In the present research, by replacing these connections with bolted connections and upgrading the experimental model performed previously at Bradford University for this purpose and simulating it using ABAQUS finite-element software, new results were obtained about these bolted shear connections. The reason behind using a software model was to avoid high cost and lack of sufficient facilities for an experimental work. For this purpose, a few models previously modeled experimentally were further modeled in ABAQUS software, and the obtained results were compared to experimental data. The comparison indicated that, the developed model could predict experimental data with good accuracy. Once finished with verifying the performed simulation, the developed model was used to undertake a parametric study on the shear connections. In this study, effects of various parameters including concrete strength, shear connection length and diameter, thickness and type of the steel sheet making up the deck on the behavior of this type of connection were investigated.