Expert: Dr. Abdulaziz Jarkas - 4/23/2007

Question
I need to work out the bending moment for a steel beam. The beam is a UDL with other loads, such as wall at points along the beam. Could you advise me on the equation etc. Because i am having trouble getting back to '0' when drawing the bending moment diagram.  

Answer
Dear Chris,

Is the beam simply supported or continuous? Each has a different equation. At any rate, the simplest way to get the bending moment at any point along the beam is to first get the reactions at the supports then choose any arbitrary point, for example one of the end supports, and sum the moment about it as you go along the span of the beam. Please note that the summation of moment at any point along the span relative to your reference point (in this case here is the one at the end supports)should be equal to zero.

Hope this helps, however, please do not hesitate to contact me should you need further assistance.

Regards,

Dr. Jarkas