Hi,
I tried two models with different Panel Calculation Model: one with Partial stiffening, and the other Without stiffening. I got two different diagrams for Mx, the former with uniform diagram and the latter with uniform varying diagram. Please find the attached pictures. I wonder why?
1- assuming you agree
2- bar 9, on YZ plane (the picture is from post 37)
counterclockwise
3- bar12, on YZ plane (the picture is from post 37)
clockwise
Ad1 - agree
Ad2 - do not agree - Mx from bar 9 acts on node 4 in clockwise direction
Ad3 - agree
So, this is why we don't have a common sense
but in the picture, I applied the sign convention stated on 1)
on the bar diagram, the value is -3.97. Applying the sign convention, if I pointed my right thumb in the direction of the local positive (x-axis) and curled my fingers, my fingers will be curled in the same direction as the positive Mx. So this will be counterclockwise on YZ plane.
But I pointed my right thumb in the direction of the local negative (x-axis) and curled my fingers, my fingers will be curled in the same direction as the negative Mx. So this will be clockwise on YZ plane.
On node 4 this will be counterclockwise. Does it make sense?
Pointing th thumb in direction of negative local x axis direction is incorrect
Moment from beam 9 acts on node 4 in clockwise direction (summation with sign "-" according to used convention).
Its direction corresponds to direction of applied load MX in example screenshot below. This load causes torsion moment Mx=-3.97 in beam 9, transferred directly to node 4
So, this sign convention (the picture below) can't be used to find the direction of Mx transferred from bar 9 to node 4?
It can be used when your thumb direction corresponds to x axis direction
For beam 6 you look at node 4 in direction "+ " of local x axis (forces are transferred to bar end node) so sign convention from point 1 should be used for Mx.
For beam 12 you look at node 4 in direction "- " of local x axis (forces are transferred to beam start node) so sign convention from point 2 should be used for My.
Do you know I didn't notice that there are two sign conventions for forces on bars: one at start point 1, and the other at end point 2.
Till now I only followed sign convention on start point 1, and if you review this thread from start, you will notice that all my discussions before were based on this sign convention on start point 1.
Thank you for your patience.
Please find the attached screencast:
From post 12:
MRy=9.49 kNm
Please find the attached link:
Robot Structural Analysis 2019 Help | Maps (panels) | Autodesk
Using this sign convention:
Checking (0.82+0.41+0.16+0.02+0.02+0.16+0.41+0.82)*(7.15-0.89)=17.65kNm
Is it comparable?
I guess that you are trying to integrate Myy moment along bottom slab edge to obtain MRy value from ppanel cuts.
You calculations are not correct.
Mry value is obtained by Myy moment integration along bottom slabb edge. So:
- Myy values at slab edge should be used for integration (actually you have used values from finite elements centers - to small values)
- You have used incorrect formula for integration (you should use "sum of Myy*dl" for each finite element, where "dl" is finite element width and "Myy" value is determined fin the center of finite element bottom edge)
Please find the attached picture:
Using Maps> With description> Description positions> Indicated graphically, I get these results
(1.48+1.36+1.24+1.15+1.15+1.24+1.36+1.48)*0.89=9.31
Using Plate and shell results, I get these results
Node Myy
2 1.54
33 1.44
34 1.33
35 1.20
36 1.15
37 1.20
38 1.33
39 1.44
4 1.54
Using interpolation, I get these values:
(1.54+1.44)/2=1.49
(1.44+1.33)/2=1.385
(1.33+1.20)/2=1.265
(1.20+1.15)/2=1.175 ...etc
(1.49+1.385+1.265+1.175+1.175+1.175+1.265+1.385+1.49)*0.89=9.46
Is my interpretation correct?
Please find the attached picture:
How this could be comparable with the Maps> Myy, Plate and shell results> MYY, or Reduced Results for panels> MRy?
I do not understand the following
"I meant Reduced moment X=9.49, here it's X instead of Y." Could you explain
Results in my pictures
1. Myy - integral in local panel system,
corresponds to
2. MRy in respect to panel cut line
and also corresponds to
3. Mx - in global system of coordinates.
Please refer to Robot help to chech results interpretation
