Internal Forces and Moment in GEBT OUTPUT

  1. Salim Chaibi

    I have a question about a beam analysis on GEBT. As you can see in the GEBT's file (isotropic.txt). I have a 3 points bending  analysis and I apply a force of 2000 N on the center of the beam (node 6).

    When I send it to analysis, it's running and i get my two files <.ech><.out>.


    The problem is when I'm watching on the output (isotropic.txt.out).

    I'm sorry, I can join just one file. If you can run the "isotropic.txt" you will obtain the output file and see on the node 6 my problem.


    When i'm looking at the line of my node 6, the  internal forces/moments of my node where the load is applied, are  set to 0. I would like to know why ?

    It should be the internal Moment M2.


    Indeed, according to the beam theory, the Bending internal Moment is at his max where I apply the load.


    thank you 


  2. Qi Wang


    In GEBT, the internal forcec/moments on the node where you prescribed external loads are set to ZERO since it is a prescribed value already. That is the reason why you have 0 in the output file for NODE 6. 

    However, you can check the internal forces/moments) through element output. For example, if NODE 6 belongs to element 5, you can scroll down and find the part of element output and the value will not be 0 there.  The fundamenalvariables, including displacements, rotations, force and moment resultants etc, are assumed to be constant within each element. Therefore, this element force/moment is also the INTERNAL resultant for NODE 6.