I cannot seem to get rotary inertia to work for ANSYS LS-DYNA MASS166 elements. Why?
This is a known error and has been fixed in ANSYS LS-DYNA 12.0, per Defect 58795.
A new test case (dyna-329s.dat) has been added to the QA Test Set. The input and
output (both 11.0, which fails and 12.0, which runs) files have been attached to this
record. The ANSYS LS-DYNA 12.0 results match those from VM47.dat, which is part
of the ANSYS implicit Verification Manual. Finally, the MASS166 documentation has
been altered to note the following:
If KEYOPT(1) = 0:
MASS - Concentrated mass (Force*Time2/Length) (must be > 0)
If KEYOPT(1) = 1:
IXX - Moment of inertia (must be > 0),
IXY - Moment of inertia,
IXZ - Moment of inertia,
IYY - Moment of inertia (must be > 0),
IYZ - Moment of inertia,
IZZ - Moment of inertia (must be > 0)