Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Different values for max Mx / My 1

Status
Not open for further replies.

Bill2001

Civil/Environmental
Joined
Aug 28, 2007
Messages
33
Location
NO
Hi friends!
I've modeled a simple supported slab of concrete 1 m x 1 m x 0.25 m in STAAD.Pro
then I applied a joint load of 100 kN at the center of the slab (in the middle of the slab).

The 1 m x 1 m slab is then
1) Meshed up 4x4 mesh (0.25 m x 0.25 m each plate element).
2) Meshed up 20x20 mesh (0.05 m x 0.05 m each plate element).

Max Mx and My (Summary) are now quite different for 4x4 mesh and 20x20 mesh !!!
Can we accept that different mesh sizes produce so different values for Mx / My?

Could you please help me out to understand the results?
Thanks a lot in advance and I do appreatiate your helps!
Bill
 
You are looking at the plate element center moment resultants table. The plate element centers are farther from the slab center and slab edge in the 4x4 model than in the 20x20 model.

If you look at the corner stresses table, then the moments are 6.30 t-m/m in the 20x20 model and 4.49 in the 4x4 model. The moments are near zero at the edges in the 20x20 model and approx. zero in the 4x4.

The center moments are different partly because of the point load at the center. A joint load, in effect, is distributed on the area that is nearest to the loaded joint. This area is much smaller in the 20x20 model than it is in the 4x4 model. So the moment at the center is more intense in the 20x20 model.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top