topic Re: Design loads for panels - Maps vs. panel cuts vs. reactions in Robot Structural Analysis Forum

Design loads for panels - Maps vs. panel cuts vs. reactions

skellyRSA2023 — Thu, 12 Jul 2018 13:27:32 GMT

Hi,

If you have a wall panel layout which is supporting axial and lateral loads as per the attached, what is the best way to review and obtain design loads for the panel design under axial compressive loads? I have attached a pdf of the panel layout (containing four sheets) which show the different design loads under the ULS- combination

1. Panel cuts showing 3 cuts, top, middle and bottom of panel showing Nxx under ULS- load combination in kN/m

2. Maps showing axial loads (Nxx) under the ULS- load combination in kN/m

3. Reactions at under the panel for the ULS combination (as the ULS- does not show in this for ULS-)

I am trying to obtain the maximum axial compressive load to design the panel piers between the window openings, however there seems to be some substantial variation in results? Could someone offer some advice on what load should be designed for.

Rgds,

Simon.

Re: Design loads for panels - Maps vs. panel cuts vs. reactions

Muhammed.OPERA — Thu, 12 Jul 2018 18:49:34 GMT

Hi @skellyRSA2023

1- For the panel cuts:

Every panel cut will get different values for (Nyy), that's logical as the load carried increase as you go down.

if you create a panel cut on the extreme down edge of the wall, you will get a graphical representation for Nyy values (KN/m) in the wall with the max. & min. values written.

2- Displaying Linear support's reactions Fz:

Using the average value means that the program will calculate the average value (KN) per meter = all reactions / length of the wall, that won't be the same value as the previous cut as the cut shows the max. min. value only (KN/m) but here take the average of all nodes (KN/m).

Using the Integral value means the sum. of all support node reactions (KN) = total carried load on the wall.

From all of the above, if you want to design the wall on the average value (KN/m) take it from the linear support reaction > average value.

If you want to design the wall on the max. value that the wall may carry (KN/m), take it from the panel cut.

Note: that panel cut values related to No. of nodes (Mesh size).

Re: Design loads for panels - Maps vs. panel cuts vs. reactions

skellyRSA2023 — Fri, 13 Jul 2018 00:23:46 GMT

Many thanks Muhammed. I take it then that the easiest way then would just be for a panel with such an opening to design based on the axial loads in the panel cuts, or add up the node reactions under each the piers between openings under the ULS- combination, if designing the individual piers.

Also, see the attached pdf sheet, is it possible to define the moments and shear forces in the header beams of the panel as I have sketched up, I have tried to define this using the panel cut method, however it doesn't seem to be indicating any moments for some reason.

Re: Design loads for panels - Maps vs. panel cuts vs. reactions

Muhammed.OPERA — Fri, 13 Jul 2018 04:04:28 GMT

Hi @skellyRSA2023

I'm not sure that i got that but,

if you mean you have modeled beams on the upper edge of the opening and you want to display B.M. and Sh. diagrams, you can display that from: Results Menu > Diagrams for bars > My or Fz.

Re: Design loads for panels - Maps vs. panel cuts vs. reactions

skellyRSA2023 — Fri, 13 Jul 2018 11:57:46 GMT

Muhammed,

See attached pdf as I don't think I explained myself so well, yes I am looking for the bending moments in the header beams, however I have not modelled these as bars, I have modelled these as a full panel with openings thus the header is part of the panel, I then draw a panel cut using two points through the header beam area. However, I think the panel cut forces are based on the local axis of the panel, thus I have used in plane and it seems that the bending moments are very low for what they are carrying thus I don't think I have done it correctly. see pdf attached. I am basically looking to find the bending moment diagram and shear diagram under ULS- load combination using panel cuts through the header beam location.

Thanks,

Simon.