Bending stress - multiple loads

[xez]

Hello all,

How do you calculate the maximum bending stress for a beam (multiple span) that has multiple evenly spaced point loads? For example, point loads at 12'' on center along a hat channel.

Would using 3PL/16 be considered worst case moment?

Thanks.

 

[klaus.]

well...very easy...you have to find the worst possible case for the design...


best regards
Klaus

 

[IFRs]

Use the principle of superposition

 

[desertfox]

Hi

You could always assume its a distributed load.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[JGard1985]

Or cheat...

Look at table 3-22C "Continuous Beams; Moments and Shear Coefficients Equal Spans, Equally Loaded" of the AISC Steel Construction Manual. It has moment distribution for distributed loads as Desertfox mentioned, and point loads up to quarter points of each span

Jeff
Pipe Stress Analysis Engineer

http://www.xceed-eng.com

 

[rb1957]

multiple equal loads can be reasonably represented as a UDL; it is a usefull exercise to plot the difference (and so understand for yourself that this is reasonable and not have to rely on "I saw it on the internet").

another day in paradise, or is paradise one day closer ?

 

[xez]

Table 3-22C in the steel book helps and I never thought of considering it a uniform load. I had drawn the moment diagrams, but didn't know if there were equations out there for all the different scenarios. Thanks for the guidance everyone.

 

[rb1957]

there's a simple solution for a single point load. For multiple loads, superimpose them.

another day in paradise, or is paradise one day closer ?