kaffy
Mechanical
- Jun 2, 2020
- 188
Good Morning Fellow Engineers,
I am working on a structure with two W40x324 beams spaced 10 feet apart, each carrying a concentrated load of 150 kips at mid-span on the top flange (attached showing AISC, YURA reference and loading condition) . My goal is to prevent lateral-torsional buckling (LTB) in accordance with AISC requirements. Since LTB is a concern with the length, I am designing bracing to reduce the effective lateral span. From my research, AISC Appendix 6 provides the necessary checks for both required flexural strength and flexural bracing. I plan to use a W21x44 section diaphragm for bracing, attaching it to transverse stiffeners positioned near the top flange of the beams. While the required flexural strength checks out, for bracing stiffness, I’ve found guidance from Yura, which suggests that if a diaphragm is used, the available stiffness can be either 6EIb/s or 2EIb/s. Since there’s no slab, I was planning to use the 2EIb/s as avalible stiffness. As this is my first time designing bracing for LTB, I would appreciate it if a senior engineer could confirm whether I’ve covered all the necessary checks or if anything might be missing.
Thank You
