Abstract
The modal assurance criterion and normalized cross-orthogonality check are widely used to assess the correlation between the experimentally determined dynamic characteristics and the finite element model predictions. In this paper, the effectiveness of these criteria on the base excitation responses of three spacecraft models is carried out. The dynamic characteristics obtained from a nominal finite element model are considered as experimental or true characteristics, and those obtained from a model produced by introducing errors in the nominal model are considered as analytically predicted characteristics. It is observed that these criteria are not suitable, particularly when the model is used to predict forced response characteristics such as the force transmitted to the base, peak acceleration response, and dynamic displacement in the spacecraft. Thus, a qualitative indicator named as base-force assurance criterion is defined by comparing the experimentally determined dynamic force at the base and the finite element predicted force such that the criterion can state the possible error in the peak acceleration and the dynamic displacement under the base excitation. The method is applied to assess the performance of three spacecraft structures, and the results show that new criterion can better correlate with the acceleration and the dynamic displacement error than the conventional criteria. Copyright © 2013 by K. K. Sairajan and G. S. Aglietti.