Expert: Bryan P. Lindsey, P.E. - 12/4/2008

Question
"hi Bryan P. Lindsey i hope that you can help me i am really strugling with the calc for the bending moment. i have a simply supported beam that has varios weights upon it i have worked out all of these and changed them into a udl(uniformly distributed weight) the spec is this we have a simply supported beam that in total has a weight (including the self weight) of 390.4 Kn the beam supporting the weight is 5m long, we have established that there is a point load from 1 side that with the self weight weighs 29.4Kn this point load is 1.5m in we have also worked out that the reaction at Ra is 89.4 and the Rb to be 78.08 Ra is higher because the point load is 1.5m from that side all i need to do now is work out the moments from left to right and vica versa if u cud help with a worked example that wud b brill i have to have this in for mon 8/12/08" pleeeeease help

Answer
It has been quite some time since I have calculated a bending moment but with that said I will try to give some advice. The sum of the moments from what I can remember is simply just distance times load. Beyond that I would have to do some research which unfortunately I do not have time for.

Bryan Lindsey, P.E.
www.seengineering.com