1-sided top and bottom beam cope

[carnahanad]

Hey everyone,

A construction issue has arisen that requires the top and bottom flange of a beam be coped out on 1 side, effectively leaving me with a channel. This cope would be required for 3 feet of a 20 foot span and would be in the first third of the beam. This beam is being used as a collector and will be subjected to tension and compression as well as flexural stresses. Does anyone have an idea as to how to check the new beam properties for the stresses?

Thanks,
Alex

 

[ishvaaag]

The properties themselves can be taken from closed form statements of the properties for C members, or you can derive from the formulas given in Roark's or Pilkey's. You can make a Mathcad worksheet for the integrals. The checks you can divide in the parts that are still double tees and channel, on "good" analysis counting the new standing properties. I would recommend to go manual with the C item if torsion is not thoroughly prevented and the element is very critical, usual ordinary checks for bending should be enough for less critical cases with sound prevention of distortion of the shape at the cut part. Yet use the equations for C items, even then.

 

[csd72]

Alex,

Can you provide a stiff lateral support at the change in section (i.e. from C to I )? This would help a lot and make things simpler.