Excentrically braced frames - How to limit link rotation
Excentrically braced frames - How to limit link rotation
(OP)
Greetings,
I am designing a 9-story building with excentrically braced frames in one direction, using the Canadian Building Code.
According to the S16-01 standard (concerning steel design), the inelastic component of the link rotation is limited to 0.08 rad (for link with e < 1.6Mp/Vp). This is my case.
However, after running a dynamic analysis and getting story drifts (to compute the rotation), I am exceeding the rotational limit.
How can I modify my design to obtain a smaller rotation (and/or smaller story drift)? I believe the actual member used in the EBF are irrelevant and do not impact much the story drift. Is it about EBF geometry, i.e. link length mostly?
I am designing a 9-story building with excentrically braced frames in one direction, using the Canadian Building Code.
According to the S16-01 standard (concerning steel design), the inelastic component of the link rotation is limited to 0.08 rad (for link with e < 1.6Mp/Vp). This is my case.
However, after running a dynamic analysis and getting story drifts (to compute the rotation), I am exceeding the rotational limit.
How can I modify my design to obtain a smaller rotation (and/or smaller story drift)? I believe the actual member used in the EBF are irrelevant and do not impact much the story drift. Is it about EBF geometry, i.e. link length mostly?






RE: Excentrically braced frames - How to limit link rotation
Adjusting the link length, or reconfiguring the braces, is usually what it takes. The link length needs to be short, but not too short and the brace angles not too steep or shallow. Adjusting the beam depth can also help.
I would also double check equivalent lateral force method static analysis results to rule out some anomaly in the results when dealing with a dynamic analysis.
RE: Excentrically braced frames - How to limit link rotation
RE: Excentrically braced frames - How to limit link rotation
Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis
http://www.engissol.com/cross-section-analysis-des...