عنوان مقاله [English]
One of the most important properties of concrete structures is their ductile behavior against earthquake. Ductility of a structure includes resisting relatively high plastic deflection without significant reduction of structure strength and absorption of earthquake energy through hysteresis behavior. Different design codes have considered requirements for ductility of various structural elements. The purpose of this study is to investigate the optimal design equation for stirrupts used in ductile reinforced concrete columns. In this investigation, stirrupts for three types of columns including the circular column with 750 mm diameter and rectangular columns with dimensions 1000×1000 and 500×500 mm in medium and high ductility were studied. Also, two types of concrete strength 30 and 60 MPa were considered to evaluate the effect of concrete strength. The required stirrupts obtained from proposed equations were compared with IR code and ACI. In addition, numerical simulation using ABAQUS software for aforementioned situations was performed. Finally, the results obtained from DBA method considering axial and rotational ductility, and cost showed that the proposed equations are the most optimal design equation in medium ductility. Also, the proposed equations are the best in high ductility when they were used to columns with concrete strength 30 MPa.