Different results for beam3 and beam188

[princebouja]

hello,
I tried to use ansys13 to study the effect of self weight on a Cantilever Beam, by following this tutorial:

http://www.mece.ualberta.ca/tutorials/ansys/IT/Density/Density.html.

But I used beam188 as beam3 is no longer supported in ansys13, and I defined a rectangular section (B=50,h=10) instead of defining real constants (which is not possible for beam188). Instead of obtaining a 5.77 mm deflection (result found in the tutorial), I obtained a 0.22 mm deflection!! I tried to modify beam188 options, but I obtained the same result
Can you explain that? Is that due to the difference between beam3 and beam188? or there is a parameter that I should fix?
Thanks for your answers.

 

[msquared48]

Is this a student problem?

Mike McCann
MMC Engineering

 

[loki3000]

i think so, but not homework. he doesn't understand the difference between the two elements.

http://mechanika2.fs.cvut.cz/old/pme/examples/ansys55/html/elem_55/chapter4/ES4-3.htm

http://www.kxcad.net/ansys/ANSYS/ansyshelp/Hlp_E_BEAM188.html

 

[IDS]

he doesn't understand the difference between the two elements.

I doubt that differences in the beam formulation would account for a difference in deflection of that magnitude. Since the ratio of the deflections is very close to 386/9810, I'd be looking at the units used for specifying the accelleration due to gravity.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/