Joist Design Considerations

[slamdfullsize]

I work for a comapany that is currently under contract to produce a material handling system. We have a working design and prototype of one of our designs. However, in the ever lasting need to make things lighter, we are currently investigating ways of doing so. One way that has come up is to lighten the frame work by switching from a W Flange to a Joist design.

I know nothing about Joists and have been doing as much research as I can to educate myself on this subject.

What I would like to know, mainly, is if a joist beam or some other type of comoposite beam would be a suitable choice for a hanging structure that will be required to lift and move with a fully loaded 20 ft iso container? It will be suspended at all 4 corners and will have concentrated loads at points that are yet to be determined.

I know this is not a lot of information, but I guess what Im looking for is if a joist beam would be able to handle this type of scenario.

Ill try to check back here several times a day incase anyone has some more questions for me or perhaps can help me answer mine.

Thanks

 

[msquared48]

If you are talking about open web steel joists, I suppose that it is possible to do that. OPne concern of mine would be the durability of the open web system as opposed to the WF system with time knowing the conditions of use. Open web joists are much more sensitive to member damage affecting the liftingcapacity than the larger members. Just remember this in your design considerations.

Mike McCann
McCann Engineering

 

[DaveAtkins]

I would shy away from steel joists for this application, because of the point loads. Steel joist bottom chords (and steel joists in general) are not great for supporting concentrated loads. They CAN support point loads, but it is not their forte.

DaveAtkins

 

[JKW05]

Ditto what ms^2 and Dave said. And the coordination of the point loads with the joist fabricator can be tedious.