Topic: MITC4 stresses
Consider the membrane patch test by Macneal, Richard H., and Robert L. Harder. "A proposed standard set of problems to test finite element accuracy." Finite elements in Analysis and Design 1.1 (1985): 3-20 [link] for the MITC4 shell.
INPUT FILE:
patch_0.out
"Patch test of MITC4Shell elements, shear"
StaticStructural nsteps 1
domain 3dshell
OutputManager tstep_all dofman_all element_all
ndofman 8 nelem 5 ncrosssect 1 nmat 1 nbc 4 nic 0 nltf 1 nset 5
node 1 coords 3 0.04 0.02 0.00
node 2 coords 3 0.18 0.03 0.00
node 3 coords 3 0.16 0.08 0.00
node 4 coords 3 0.08 0.08 0.00
node 5 coords 3 0.00 0.00 0.00
node 6 coords 3 0.24 0.00 0.00
node 7 coords 3 0.24 0.12 0.00
node 8 coords 3 0.00 0.12 0.00
mitc4shell 1 nodes 4 5 6 2 1
mitc4shell 2 nodes 4 6 7 3 2
mitc4shell 3 nodes 4 7 8 4 3
mitc4shell 4 nodes 4 8 5 1 4
mitc4shell 5 nodes 4 1 2 3 4
SimpleCS 1 thick 0.001 material 1 set 1 drillType 1 relDrillStiffness 0.01
IsoLE 1 d 2. E 1e6 n 0.25 tAlpha 0.000012
BoundaryCondition 1 loadTimeFunction 1 dofs 3 1 2 3 values 3 0 0 0 set 2
BoundaryCondition 2 loadTimeFunction 1 dofs 2 1 2 values 2 0.00024 0.00012 set 3
BoundaryCondition 3 loadTimeFunction 1 dofs 2 1 2 values 2 0.00030 0.00024 set 4
BoundaryCondition 4 loadTimeFunction 1 dofs 2 1 2 values 2 0.00006 0.00012 set 5
ConstantFunction 1 f(t) 1.0
Set 1 elementranges {(1 5)}
Set 2 nodes 1 5
Set 3 nodes 1 6
Set 4 nodes 1 7
Set 5 nodes 1 8
OUTPUT (selected):
element 1 ( 1):
GP 1 : forces 1.3333e+00 1.3333e+00 0.0000e+00 0.0000e+00 0.0000e+00 4.0000e-01
moments 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00
strains 1.0000e-03 1.0000e-03 0.0000e+00 0.0000e+00 0.0000e+00 1.0000e-03
curvatures 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00 0.0000e+00
GP 1.1 : strains 1.0000e-03 1.0000e-03 0.0000e+00 0.0000e+00 0.0000e+00 1.0000e-03
stresses 1.3333e+03 1.3333e+03 0.0000e+00 0.0000e+00 4.0000e+02 0.0000e+00
GP 1.2 : strains 1.0000e-03 1.0000e-03 0.0000e+00 0.0000e+00 0.0000e+00 1.0000e-03
stresses 1.3333e+03 1.3333e+03 0.0000e+00 0.0000e+00 4.0000e+02 0.0000e+00
ISSUE:
Looks like that σxy is messed with σzx.