Damage Concentration and Column Flexural Demands in Steel Chevron Braced Frames Designed to Canadian Provisions

This paper evaluates the seismic performance of steel chevron braced frames with emphasis on damage concentration and column flexural demands. A set of chevron braced frames is selected by varying the number of storeys and beam design strategy, i.e., weak beam and strong beam. The frames are designed in accordance with the 2019 Canadian steel design standard. The seismic response of the frames is then examined using nonlinear dynamic analyses. The results of dynamic analyses are used to quantify and interrogate the distribution of frame lateral deformations and in-plane flexural demands induced in the columns, and assess the Canadian design provisions aiming to mitigate drift concentration in steel braced frames. The results confirm the potential for damage concentration in chevron braced frames, with more pronounced response in weak beam design cases regardless of the frame height. Appreciable in-plane bending is observed in the columns in the storeys where the majority of frame lateral deformation tends to occur. Recommendations for enhancing the current Canadian seismic provisions for columns of chevron braced frames are proposed.