elements through the thickness 1

[SKJoe]

Hi,

is ansys help file to shell 181 is written :

....a number of elements through the thickness direction is necessary....what does this mean ? - when using shell elements i can only attach one element to one surface and via real constant attach its thickness, of course i can attach a number of layers to this thickness...but probably
expression element is not the same as layer...

so how to do this "element through the thickness" in accordance with shell elements ?

thanx

 

[cbrn]

Hi,
I think the sentence is refered to when you use shell section definition instead of real constant. Above in the same chapter of SHELL181 element description, it is said that using real constants for shell181 is not precluded, but that using shell section is more "general" and alows more control and options.

Regards

 

[SKJoe]

thanx for your effort cbrn, but i probably didnt explain my problem correctly, i will try again :

i want to try use reduced integration of shell181 and this use is connected with requirement "...a number of elements through the thickness direction is necessary"

so my question is : which way to do this ? because if i did this "a number of elements through the thickness" literally (lets say for 4 elements through the thickness of shell ), i would create 4 surfaces and attach 1/4 thickness to each surface, but furthermore i would tie the nodes of this surfaceces together, because otherwise these 4 surface will not act as one entity...

so i think there must be another better way to do this...

 

[meshparts]

Hi SKJoe,

You should look at the Figure 4.181-2 on the description page of the Shell181 element. The "thickness direction" is not the thicknes of the shell element! It is the thicknes in the load direction. Read carefully the description of this element. It says, if your shell elements have in plane bending and if you are using the reduced integration, then you should have more then 4 elements through the "thickness direction" not "through the thickness of shell" as you interpreted.

Do your elements have in plane bending? Then use more than 4 elements in the direction of bending.

Regards
Alex