*HEADING
Two flat plates separated with four stiffeners
*PARAMETER
** modal input parameters
numModes = 2000
lowFreq  = 0.0
highFreq = 1502.0
**
** number of nodes in x3-direction (all other mesh
** parameters depend on this number)
**
nnz= 7
** number of stiffeners
NSTIFF = 4
** number of nodes in x1-direction
nnx= 3 * nnz + 1
** number of nodes in x2-direction
nny= 9 * nnz + 1
** number of elements in x1-direction
nex= nnx-1
** number of elements in x2-direction
ney= nny-1
** number of elements in x3-direction
nez= nnz-1
** length of plate
lz= 1.0
** width of plate
lx= 3.0*lz
** depth of structure
ly= 9.0*lz
**
** mesh generation parameters
**
nyp1= nny+1
nyp2= nny+2
mid= (nnx+1)/2*(nny-1)+1
**
nnbot = nnx*nny
nebot = nex*ney
nntot = nnx * nny * nnz
netb  = 2*nebot
**
netbp1 = netb+1
nnbotp1 = nnbot+1
nnbotp2 = nnbot+2
nn3   = nnx*nny-nny+1
nn3p1 = nn3+1
nn3m1 = nn3-1
nn5   = nntot-nnbot+1
nn6   = nn5 + nny-1
nn7   = nntot-nny+1
nn8   = nntot
nn5m1 = nn5-1
**
** parameters for stiffener meshes
**
srn1  = 2*nnbot-nny+1
srn1p1= 2*nnbot-nny+2
sre1  = 2*nex*ney + ney*nez + 1
**
s1n1  = (nnx-1) / 3 * nny + 1
s1n1p1= s1n1+1
s1n1pn= s1n1 + nnbot
s1n1pn1= s1n1pn + 1
s1n2  = s1n1 + nny - 1
s1n3  = s1n1 + (nnz-1)*nnbot
s1n4  = s1n3 + nny - 1
s1e1  = 2*nex*ney + 2*ney*nez + 1
**
s2n1  = 2 * (nnx-1) / 3 * nny + 1
s2n1p1= s2n1+1
s2n1pn= s2n1 + nnbot
s2n1pn1= s2n1pn + 1
s2n2  = s2n1 + nny - 1
s2n3  = s2n1 + (nnz-1)*nnbot
s2n4  = s2n3 + nny - 1
s2e1  = 2*nex*ney + 3*ney*nez + 1
**
** Nodal coordinates
**
*NODE, NSET=N1
1, 0.0, 0.0, 0.0
*NODE, NSET=N2
<nny>, 0.0, <ly>, 0.0
*NGEN, NSET=BOTLEFT
1,<nny>,1
*NCOPY, CHANGENUMBER=<nn3m1>, OLDSET=BOTLEFT, NEWSET=BOTRIGHT, SHIFT
<lx>, 0.0, 0.0
0.0,0.0,0.0,0.0,1.0,0.0,0.0
*NFILL, NSET=BOTNODES
BOTLEFT, BOTRIGHT, <nex>, <nny>
*NCOPY, CHANGENUMBER=<nn5m1>, OLDSET=BOTNODES, NEWSET=TOPNODES, SHIFT
0.0, 0.0, <lz>
0.0,0.0,0.0,0.0,1.0,0.0,0.0
** left side nodes
*NSET, NSET=TOPLEFT, GENERATE
<nn5>,<nn6>,1
*NFILL, NSET=LEFTSIDE
BOTLEFT, TOPLEFT, <nez>, <nnbot>
**
** stiffener 1 nodes
**
*NSET, NSET=BOTSTF1, GENERATE
<s1n1>,<s1n2>,1
*NSET, NSET=TOPSTF1, GENERATE
<s1n3>,<s1n4>,1
*NFILL, NSET=STIFF1
BOTSTF1, TOPSTF1, <nez>, <nnbot>
**
** stiffener 2 nodes
**
*NSET, NSET=BOTSTF2, GENERATE
<s2n1>,<s2n2>,1
*NSET, NSET=TOPSTF2, GENERATE
<s2n3>,<s2n4>,1
*NFILL, NSET=STIFF2
BOTSTF2, TOPSTF2, <nez>, <nnbot>
**
** right side nodes
**
*NSET, NSET=TOPRIGHT, GENERATE
<nn7>,<nn8>,1
*NFILL, NSET=RIGHTSIDE
BOTRIGHT, TOPRIGHT, <nez>, <nnbot>
**
** monitor nodeset
**
*NSET, NSET=MIDNODE
<mid>,
**
** Elements
**
*ELEMENT, TYPE=S4R, ELSET=BOTPLATE
1,1,<nyp1>,<nyp2>,2
*ELGEN, ELSET=BOTPLATE
1,<ney>,1,1,<nex>,<nny>,<ney>
*ELCOPY, OLD SET=BOTPLATE, NEW SET=TOPPLATE, SHIFT NODES=<nn5m1>,
 ELEMENT SHIFT = <nebot>
** left stiffener elements
*ELEMENT, TYPE=S4R, ELSET=LEFTSIDE
<netbp1>,1,2,<nnbotp2>,<nnbotp1>
*ELGEN, ELSET=LEFTSIDE
<netbp1>,<ney>,1,1,<nez>,<nnbot>,<ney>
**
** stiffener 1 elements
**
*ELEMENT, TYPE=S4R, ELSET=STIFF1
<s1e1>,<s1n1>,<s1n1p1>,<s1n1pn1>,<s1n1pn>
*ELGEN, ELSET=STIFF1
<s1e1>,<ney>,1,1,<nez>,<nnbot>,<ney>
**
** stiffener 2 elements
**
*ELEMENT, TYPE=S4R, ELSET=STIFF2
<s2e1>,<s2n1>,<s2n1p1>,<s2n1pn1>,<s2n1pn>
*ELGEN, ELSET=STIFF2
<s2e1>,<ney>,1,1,<nez>,<nnbot>,<ney>
**
** right stiffener elements
**
*ELEMENT, TYPE=S4R, ELSET=RIGHTSIDE
<sre1>,<nn3>,<nn3p1>,<srn1p1>,<srn1>
*ELGEN, ELSET=RIGHTSIDE
<sre1>,<ney>,1,1,<nez>,<nnbot>,<ney>
** all elements
*ELSET, ELSET=ALL
BOTPLATE, TOPPLATE, LEFTSIDE, RIGHTSIDE, STIFF1, STIFF2
**
** Physical and material properties
**
*SHELL GENERAL SECTION, ELSET=ALL, MATERIAL=STEEL
0.01
*MATERIAL, NAME=STEEL
*ELASTIC
200.E9, 0.3
*DENSITY
7800.0
**
** Step definition
**
*STEP
Frequency extraction
*FREQUENCY, NUMBER INTERVAL=4
<numModes>,<lowFreq>,<highFreq>
*BOUNDARY
BOTLEFT, ENCASTRE
BOTRIGHT, ENCASTRE
*output, field, freq=0
*END STEP