Civil Engineering Association

Can anybody here can give technique,tips or correct procedure in preparing a manual mesh in slab, in a fast way using etabs software.

Thanks in advance.

assign auto mesh
then go to edit.....mesh areas and divide the slab into lets say 4x4 squares

(11-03-2009, 03:20 PM)rohailiyaz Wrote: [ -> ]assign auto mesh
then go to edit.....mesh areas and divide the slab into lets say 4x4 squares

dividing the slab is not applicable for more the 4 sided area, so we need to sub-divide the irregular area by forming quadrilateral which is time consuming.
What I'm doing is I make a quadrilateral area that will occupy the whole slab area, then make a null line in all the corner,edges, opening column point in x and y direction. I will mesh the big quadrilateral by meshing the area with selected lines option, then delete the unnecessary area.
Anybody have better technique in manual meshing that can reduce the time.

A model with manually meshed slab elements will always run faster than slab elements that have auto meshing using null lines.

Hi, Guys

I had done meshing by using two softwares...

Import the dxf file into ROBOT, you have a meshing option there which will mesh the areas into rectangle/quadrilateral, from there saveas dxf again and import into ETABS. But after importing check for overalping areas if any. It gave good results and finer meshing for me.

You can try the above.

Regards,

Jaks

(11-10-2009, 06:20 AM)jaks Wrote: [ -> ]Hi, Guys

I had done meshing by using two softwares...

Import the dxf file into ROBOT, you have a meshing option there which will mesh the areas into rectangle/quadrilateral, from there saveas dxf again and import into ETABS. But after importing check for overalping areas if any. It gave good results and finer meshing for me.

You can try the above.

Regards,

Jaks

"robot" meshing is good but in most cases you have to check for overlaps as you mentioned which create warnings and instability in ETABS. in my case i use adapt or ram concept for meshing but not so user-friendly compared to robot. depending on my building geometry i choose between robot and adapt on a case to case basis.

And how about meshing of membrane member, special for complex paragon shapes?

Rgds,

Kiwi

hi guys i m tring since 4 days to use the automesh or even the manual mesh on slabs ( membrane) but i don`t know why these slabs are giving me a very high and un realistic displacemets (imean in miles ) even the model is very simple cos i was trying to compare betwen the three deferent slabs ( mesh . membrane ,plate )
when i dow the automesh for the membrane an i define the size of the element to 1 m
i got the loads distributed but the displacenets are not right ( somthing like 2000 miles )
funny isnt
i was wandering in any of you could give me a solution
(im using etabs 9.5)

Use shell elements, not membrane elements.

The program is right. Its over interpretration or ignorance. When U define slab for out of plane external forces as membrane it will only distribute load as per yeild line tributary area on edge beams and column but do not have any out of plan stiffness thats why it gives high displacement. There fore for displacement always define as plate or shell.
with regards