Analyses and evaluations for composite-moment frames with SMA PR-CFT connections

作者：Hu Jong Wan^*; Leon Roberto T

来源：Nonlinear Dynamics, 2011, 65(4): 433-455.

DOI：10.1007/s11071-010-9903-3

• Shape memory alloys
• Concrete-filled tube columns
• Spring elements
• Joint models
• Composite-moment frames
• Nonlinear analyses

This paper describes seismic performance and evaluation for composite-moment frames (C-MF) with a new type of bolted connections. The study is purely analytical and explores the effort needed to establish new connection parameters without large-scale physical testing. The innovative aspects of this research are in the use of partial restraint (PR) connections between steel beams and concrete-filled tube (CFT) columns that utilize a combination of low-carbon steel and shape memory alloy (SMA) components as the main force transfer elements in the connections. The intent is to utilize the recentering provided by super-elastic shape memory tension bars to reduce building damage and residual drift after a major earthquake, and the energy dissipation of low-carbon steel components in parallel. Accurate modeling and computational efficiency were achieved through the use of a simplified joint element which includes all connection strength and deformation components. Four- and six-story C-MF models were designed for a high seismic zone in the western USA. Two connection types and three column systems installed at these prototype frame models were investigated through nonlinear pushover and dynamic analyses. The C-MF models with new bolted connections were compared to those with traditional welded connections. The results of numerical analysis demonstrate that C-MF with new PR connections show superior structural performance as indicated by small residual deformation and better distribution of the demand over the height of the structure.

• 出版日期2011-9