Two types of elements in a CGX mesh

Hello, I have the following .fbd file:

#!/bin/bash
#For the beam elements
valu c 1.
valu h 0.1
valu dy 1.0
valu ndx 0.05
valu ndy 0.018

pnt p1 -0.05 0 0
pnt p2 -0.05 0 dy
line l1 p1 p2 1
seta fix1 all
swep fix1 fix1 tra h 0 0 0
seta fix1 all
comp fix1 do

swep all wing tra 0 1 0 0
seta surface s A002 A003 A004
comp surface do


seta length l L00A L00B L008 L009
seta width l L002 L003 L006 L007

div length auto ndy
div width auto ndx
elty all he8
mesh all

send all abq
send fix1 abq nam
send surface abq nam

view elem

plot f all

sys mv surface.nam interface_beam.nam
sys mv fix1.nam fix1_beam.nam

The application is such that I need to have only one division in the Z direction. This prevents me from using the he20 type elements. Is it possible to have second order elements in the 2D XY plane?

My knowledge of the syntax for .fbd files is limited and hence I seek help in this direction. Many thanks!

hello
i would help, but i don’t understand your question or your concerns
if you describe better or add a sketch, maybe helps

wbr

Hello @dichtstoff ,
thanks for your reply, I will try to explain my case better. Here is a figure of my geometry:

There are two divisions in the X directions, multiple divisions in the Y direction and a single division in the Z direction. I am restricted by the application and have to maintain these divisions. Can I use second order elements he20 or other? Right now if I select anything else than he8 then the resulting geometry files from the command cgx -b pre_flap.fbd are empty.

it is empty because of bad division of your lines
to mesh with “elty all he20” your lines divison have to be odd numbers.
you can check these with “plot ld all”

if you change your fbd file

line l1 p1 p2 1
to
line l1 p1 p2 4

it should work with HE20

if you want have two different elements together,
you can create these with common lines of your bodies
or after meshing with merg command

1 Like

Thanks @dichtstoff ! That resolves my problem! Thanks for your help :slight_smile: