Top Loaded S-section, Supported Solely on Bottom Flange
Top Loaded S-section, Supported Solely on Bottom Flange
(OP)
Hi all,
I'm analyzing a steel frame structure that is used to support a crane system. The two S-sections that act as tracks for the crane trolley are two-span continuous, and are fastened with bolts to the top of the columns. This is the only type of support given to them (top flange is completely unbraced). I believe this setup will have an effect on the unsupported length during analyses, but I'm having difficulty being able to define that effect. Galambos' research "Guide to Stability Design Criteria for Metal Structures" addresses this issue, however only in a cantilever system. Has anyone else encountered this type of system or have an idea where to find the appropriate resources needed to solve it?
Thanks
I'm analyzing a steel frame structure that is used to support a crane system. The two S-sections that act as tracks for the crane trolley are two-span continuous, and are fastened with bolts to the top of the columns. This is the only type of support given to them (top flange is completely unbraced). I believe this setup will have an effect on the unsupported length during analyses, but I'm having difficulty being able to define that effect. Galambos' research "Guide to Stability Design Criteria for Metal Structures" addresses this issue, however only in a cantilever system. Has anyone else encountered this type of system or have an idea where to find the appropriate resources needed to solve it?
Thanks






RE: Top Loaded S-section, Supported Solely on Bottom Flange
RE: Top Loaded S-section, Supported Solely on Bottom Flange
BA
RE: Top Loaded S-section, Supported Solely on Bottom Flange
S-sections have heavy webs, so it may be more feasable with an S-section than with a wide-flange beam.
Railroad rails are supported only on the bottom flange, so that installation is not unknown.
RE: Top Loaded S-section, Supported Solely on Bottom Flange
Not having any lateral support for a crane runway beam is a very bad thing. The side thrust lateral loading on the girders from the crane needs to be resisted and taken into the support structure. If there is no top flange bracing, the lateral force from the crane will transfer to the top flange of the girder (weak axis) and cause local bending in the web of the girder. This can cause the web of the girder to crack usually near the web toe of the fillet.
RE: Top Loaded S-section, Supported Solely on Bottom Flange
RE: Top Loaded S-section, Supported Solely on Bottom Flange
BA
RE: Top Loaded S-section, Supported Solely on Bottom Flange
http://imgur.com/pbtl6
RE: Top Loaded S-section, Supported Solely on Bottom Flange