Forum

Gebt Internal Forces

1. I have a problem with a 3 pts bending analysis.

I have 29 nodes with 28 Elements.

The Node 14 is the center of the beam. I'm applying a load of 100 N on the z-axis.
When I'm looking for the Internal Forces for this Element, as you explained to me  I have to look in the sub Element.
I did it but the problem is :

if  I take the Internal Forces from the member 13 the Internal Force F3 =-50N.

if I take the Internal Forces from the member 14 the Internal Force F3 =50N.

But according to the beam theory the I-F F3 has to be set to 0 for my node 14.
So taking the Internal Forces from Member  is false for me.
What should I've to do ?
Because I'm doing a post-processor to visualize stress and I'm blocked with this. When the computer is going to pick the Node 14 he picks also the internal Forces of Member 13 or 14.

I join my gebt file <.dat> and <.out>

Thank you

2. Hi Salim, The internal shear force distribution in a 3-point bending case is as you described, opposite value on two sides of the load point, see the wiki: https://commons.wikimedia.org/wiki/File:SimpSuppBeamPointLoad.svg You need to look into the problem and decide which quantity is of interest. Qi On Fri, Nov 17, 2017 at 4:01 AM, Salim Chaibi @ cdmHUB - The Composites HUB <support@cdmhub.org> wrote: ---- Emailed forum response from aaron.qi.wang@gmail.com
3. Shear force at the mid point is undefined. -----Original Message----- ---- Emailed forum response from wenbinyu@purdue.edu
4. Okay.
So for my node in the middle of the beam where I'm applying a Force.
I have to put the internal Shear Force F3. I have to put even the Intenal shear Force of the Left Member or Internal shear Force of the right member but i can't put 0 ?