Buckling restrained braces （BRBs） have been widely applied in seismic mitigation since they were introduced in the 1970s. However, traditional BRBs have several disadvantages caused by using a steel tube to envelope...Buckling restrained braces （BRBs） have been widely applied in seismic mitigation since they were introduced in the 1970s. However, traditional BRBs have several disadvantages caused by using a steel tube to envelope the mortar to prevent the core plate from buckling, such as： complex interfaces between the materials used, uncertain precision, and time consumption during the manufacturing processes. In this study, a new device called the multi-curve buckling restrained brace （MC-BRB） is proposed to overcome these disadvantages. The new device consists of a core plate with multiple neck portions assembled to form multiple energy dissipation segments, and the enlarged segment, lateral support elements and constraining elements to prevent the BRB from buckling. The enlarged segment located in the middle of the core plate can be welded to the lateral support and constraining elements to increase buckling resistance and to prevent them from sliding during earthquakes. Component tests and a series of shaking table tests on a full-scale steel structure equipped with MC-BRBs were carried out to investigate the behavior and capability of this new BRB design for seismic mitigation. The experimental results illustrate that the MC-BRB possesses a stable mechanical behavior under cyclic loadings and provides good protection to structures during earthquakes. Also, a mathematical model has been developed to simulate the mechanical characteristics of BRBs.展开更多
The buckling resisting brace(BRB)is an efficient system against lateral loads that enjoy high seismic energy absorption capacity.Although desirable behavior of BRBs has been confirmed,the stiffness of the system is no...The buckling resisting brace(BRB)is an efficient system against lateral loads that enjoy high seismic energy absorption capacity.Although desirable behavior of BRBs has been confirmed,the stiffness of the system is not desirable that it can be compensated by changing the configuration of BRB braces.In so doing,the configuration in the form of double K(DK)is investigated to achieve more favorable behavior.Also,the required mathematical formulas were proposed to design the system.Comparison of DK system with other conventional BRB showed that the DK system has a better structural performance and is more economical(due to needing less core area)than other conventional BRB.Numerical results indicated that the DK system increases the lateral ultimate strength,lateral nonlinear stiffness,and energy absorption.Besides,the DK configuration reduces the axial forces created in columns in the nonlinear zone.Reducing material demand,created forces in the main frame,and also increasing of nonlinear stiffens by DK improve the structure’s safety.展开更多
基金Science Council in Chinese Taipei Under Grant No.NSC 94-2211-E-035-015
文摘Buckling restrained braces （BRBs） have been widely applied in seismic mitigation since they were introduced in the 1970s. However, traditional BRBs have several disadvantages caused by using a steel tube to envelope the mortar to prevent the core plate from buckling, such as： complex interfaces between the materials used, uncertain precision, and time consumption during the manufacturing processes. In this study, a new device called the multi-curve buckling restrained brace （MC-BRB） is proposed to overcome these disadvantages. The new device consists of a core plate with multiple neck portions assembled to form multiple energy dissipation segments, and the enlarged segment, lateral support elements and constraining elements to prevent the BRB from buckling. The enlarged segment located in the middle of the core plate can be welded to the lateral support and constraining elements to increase buckling resistance and to prevent them from sliding during earthquakes. Component tests and a series of shaking table tests on a full-scale steel structure equipped with MC-BRBs were carried out to investigate the behavior and capability of this new BRB design for seismic mitigation. The experimental results illustrate that the MC-BRB possesses a stable mechanical behavior under cyclic loadings and provides good protection to structures during earthquakes. Also, a mathematical model has been developed to simulate the mechanical characteristics of BRBs.
文摘The buckling resisting brace(BRB)is an efficient system against lateral loads that enjoy high seismic energy absorption capacity.Although desirable behavior of BRBs has been confirmed,the stiffness of the system is not desirable that it can be compensated by changing the configuration of BRB braces.In so doing,the configuration in the form of double K(DK)is investigated to achieve more favorable behavior.Also,the required mathematical formulas were proposed to design the system.Comparison of DK system with other conventional BRB showed that the DK system has a better structural performance and is more economical(due to needing less core area)than other conventional BRB.Numerical results indicated that the DK system increases the lateral ultimate strength,lateral nonlinear stiffness,and energy absorption.Besides,the DK configuration reduces the axial forces created in columns in the nonlinear zone.Reducing material demand,created forces in the main frame,and also increasing of nonlinear stiffens by DK improve the structure’s safety.
