Shell vs Frame element results correlation
Shell vs Frame element results correlation
(OP)
Greetings,
I conducted a couple of studies to compare results from analysis of frame element and shell element for a given loading.
The condition involved in the first case a cantilevered wall (24" thick and 24" long) and a 24x24 column. The results for deflection were within 2%
However, when I tried to model a cantilever beam (24x24 beam) and a cantilevered wall (24" deep, 24" thick).....the results were not right. The wall element was about 2 times stiffer.
All analysis were done in ETABS. How do I go about modeling a cantilevered deep beam in ETABS? I want to be able to use shell elements. The only way I could get it to work was by modeling a 24" wide x 24" deep slab. Why would the program treat the 24" deep cantilevered wall much stiffer?
Am I doing something retarded? Any help is appreciated.
I conducted a couple of studies to compare results from analysis of frame element and shell element for a given loading.
The condition involved in the first case a cantilevered wall (24" thick and 24" long) and a 24x24 column. The results for deflection were within 2%
However, when I tried to model a cantilever beam (24x24 beam) and a cantilevered wall (24" deep, 24" thick).....the results were not right. The wall element was about 2 times stiffer.
All analysis were done in ETABS. How do I go about modeling a cantilevered deep beam in ETABS? I want to be able to use shell elements. The only way I could get it to work was by modeling a 24" wide x 24" deep slab. Why would the program treat the 24" deep cantilevered wall much stiffer?
Am I doing something retarded? Any help is appreciated.






RE: Shell vs Frame element results correlation
RE: Shell vs Frame element results correlation
corus
RE: Shell vs Frame element results correlation
I have sent CSI support team a question to see what their response is.
I also conducted more studies and found the results to correlate when I model a 24" wide x 24" deep slab element. I am waiting for more answers.
RE: Shell vs Frame element results correlation
corus
RE: Shell vs Frame element results correlation
From the results of a FE analysis, the results for a cantilevered column and cantilevered wall with same EI was within 2% of one another.
Cantilevered column/ Wall - in the vertical plane
However, the results of a cantilevered beam and cantilevered wall are compared, the results are way off.
Cantilevered beam / cantilevered wall - in the horizontal plane
The file I sent is an ETABS analysis file, in case anyone wants to download and run in ETABS.
RE: Shell vs Frame element results correlation
corus
RE: Shell vs Frame element results correlation
RE: Shell vs Frame element results correlation
Thanks
RE: Shell vs Frame element results correlation
corus
RE: Shell vs Frame element results correlation
"In ETABS, panels elements (i.e. shear walls) are specialized to provide compatibility with frames. This elements has internal special beam elements at the wall edges to provided fixity to link beams. The wall element should only be used to model the large columns and walls. Using this element for beam behavior causes over stiff modeled unless beam is meshed along the height and has more refined meshing. This element stiffness is more realistic for practical purposes"