نوع مقاله : علمی - پژوهشی
نویسندگان
1 دانشجوی کارشناسی ارشد، دانشکده فنی و مهندسی، دانشگاه محقق اردبیلی، اردبیل، ایران
2 دانشیار، دانشکده فنی و مهندسی، دانشگاه محقق اردبیلی، اردبیل، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Implementation of openings in beams web has been introduced as an innovative method for improving seismic performance of steel moment frames. The limited length of the opening zone and formation of the Vierendeel mechanism in this area causes the reduction of beam horizontal length in nonlinear behavior range. This is while, the rigidity of the structural floor system prevents the reduction of the beam span length. This causes the creation of tensile force in the beam which is known as the second order effect. In this article a numerical study is conducted to evaluate the influence of the second order effects on the cyclic behavior of steel beams with web opening. For this purpose, a perforated steel beam has been modeled in Abaqus software and its results has been validated using laboratory test data. The numerical models have been analyzed considering different opening dimensions and three different profiles for the beam cross-section. This is done once with and once again without considering the second order effects and the results are compared. Based on the results, considering the second order effects changes the behavior of the beam in the reduced area and prevents the stiffness and strength decrease in the post-capping part of the hysteresis curve. The amount of additional strength caused by second order effects is negligible for drift ratios smaller than 2%, but it increases with the increase of loading amplitude. At 6% drift ratio, the amount of this additional strength varies between 44% and 120%, depending on the dimensions of the opening. Determination of this additional strength as a function of lateral drift ratio and opening dimensions for use in the analysis and design of beams with web openings can be considered as the main innovation of this research.
کلیدواژهها [English]
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