EXPERIMENTAL STUDY ON SEISMIC PERFORMANCE OF ENERGY DISSIPATION AND POSITION LIMITATION STEEL BRACE AND STRUCTURE SEISMIC VULNERABILITY ANALYSIS

A kind of energy dissipation and position limitation type steel brace is proposed to improve the seismic performance of a building structure. Five steel braces are designed, and the limitation displacement, limitation block number, steel core section size and length are chosen as the design parameters. Based on the test study, the characteristics including the failure mode, hysteresis loops behavior, skeleton curves, and stiffness are demonstrated. The seismic collapse resistance of steel braced frame structures is evaluated through IDA analysis. The results show that: the steel brace structure is reasonable with stable hysteretic performance, and the position limitation block could play a limiting role and provide greater additional stiffness. The number and section size of the position limitation block and the weld stiffness of the joint surface with the steel core affect the lifting degree of the additional stiffness. The calculation results of the stiffness formulas presented are in a good agreement with the experimental values, which can provide a reference for the practical design of steel braces. The collapse reserve coefficient of this type of steel braces with position limitation blocks is increased, beneficial to improve the collapse resistance of soft first storey building.