ANSYS Class3 Error Report
ERROR NO: 2008-04
ROTORDYNAMICS SYNCHRO GYROSCOPIC MATRIX SOLID ELEMENTS HARMONIC ANALYSIS
Description of Error:
Synchronous response using the SYNCHRO command in a harmonic (ANTYPE=HARMIC) analysis
is incorrect when all of the following conditions are met:
1. gyroscopic matrix is turned on (CORIOLIS,ON,,,ON), and
2. rotating structure contains element types SOLID45, SOLID95, SOLID185, SOLID186 and/or
3. synchronous excitation is specified through SYNCHRO command.
The error occurs since the rotational velocity, Omega, used for calculating the gyroscopic matrix of
solid elements is not updated as per the equation (shown on SYNCHRO command):
Omega = 2*PI*f / Ratio
f = frequency of excitation specified through the HARFRQ command
Omega = rotational velocity used for calculating the gyroscopic matrix
Ratio = synchronous ratio input through the SYNCHRO command
Instead, the gyroscopic matrix is erroneously calculated with a constant rotational velocity input
through either the OMEGA or the CMOMEGA command.
Typical GUI Path(s):
Neither the CORIOLIS nor the SYNCHRO commands are available through the GUI.
First Incorrect Version:
Suggested User Action For Running on Uncorrected Version:
There is no workaround using SYNCHRO command. Harmonic analysis to rotating forces may be
performed one loadstep/substep at a time by changing the rotational velocity (and amplitude of the
forces in the case of unbalance) for each loadstep/substep.
Author Signature: Aline Beley 3/3/2008 2:34
Reviewed By QA: William J. Bryan 3/19/2008 11:27
Approval: Dave Conover 3/3/2008 9:44