I have defined a local coordinate system in ANSYS Design Simulation 8.0
and it seems to give the correct stress output, but the strains appear to
be wrong. Is this a known error?
Yes. Defect 21931 was filed and then fixed in ANSYS Simulation 8.1.
It is an ANSYS Workbench Class 3 Error. The final version of the error
report is not yet available, but the draft contents are shown below. The
final Class 3 Error number is also not yet available.
Record Number: 21931
Type of Record: Class3 Error Report
Strains are transformed incorrectly into local coordinate systems.
Strains are assembled into tensor form incorrectly while performing the
transformations from the global system into local systems as follows.
From the strain components Ex, Ey, Ez, Exy, Eyz, Ezx, the following
incorrect assembled strain tensor is used for the transformations,
producing incorrect results:
Ex Exy Ezx
Exy Ey Eyz
Ezx Eyz Ez
The correct assembled strain tensor that should be used is:
Ex 0.5*Exy 0.5*Ezx
0.5*Exy Ey 0.5*Eyz
0.5*Ezx 0.5*Eyz Ez