LOCATION OF MODELING ERRORS USING MODAL TEST DATA

A unity check method is proposed to locate the physical positions of modeling errors in stiffness using modal test data. The method uses the cross-unity check between a flexibility matrix derived from modal test data and the analytical stiffness matrix to locate the errors; the method cannot determine the changes needed to correct the errors. The approach arrives at a formulation similar to one proposed previously by Ojalvo and Pilon. Effectiveness of the method is demonstrated through numerical examples using simulated mode test data and analytical stiffness matrices unreduced or reduced by Guyan reduction. Sensitivity of the method to lack of orthogonality in measured modes is discussed. Note that the flexibility matrix can also be derived from static test data instead of modal test data. © 1990 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.