عنوان مقاله [English]
Use of steel plate shear walls (SPSW) as an effective structural system for resisting lateral force in low- to mid-rise buildings increased in recent years. The SPSWs control the lateral force response of the building and the building's natural period of vibration. The SPSW with coupling beam (SPSW-WC) system consists of a pair of planes SPSWs linked together with coupling beam at the floor level. The degree of coupling (DC), which represents the level of interaction between the two piers, is a key parameter in understanding behavior and developing design for the system. Determining the DC is difficult, but necessary. Therefore, this study investigates the relationship between DC and building's natural period of vibration in SPSW-WC structural system.Some analytical 3-, 6-, and 9-story structures with different lengths of link beams were analyzed for determining first two natural periods and evaluating DC of SPSW-WCs. This study applied a new design technique using orthotropic membrane model proposed in design codes. In this method, after preliminary design of the system, in order to distribute correctly the forces between the wall members, an orthotropic membrane model was developed using ETABS program. Natural period estimations using this method were compared with the finite-element solution, and good agreement is demonstrated.Based on outcomes, an increase in stiffness of coupling beam results in increasing in coupled steel plate shear wall's degree of coupling. On the other hand, an increase in stiffness of coupling beam results in a decrease in structure's first natural periods of vibration. However, if degree of coupling tends to one, then first natural period of structure does not affect stiffness of coupling beam. This paper also presents a model for estimating the DC of SPSW-WC from the first two natural periods of vibration.