Criteria for modeling accuracy: A state-of-the-practice survey

Modal survey tests are routinely performed on aerospace structures as a means of qualifying analytical models for loads prediction, control systems design and stress analysis. All of these involve numerical simulations upon which design, development and operational decisions are based. Numerous metrics have been proposed and used for assessing modeling accuracy, including comparisons of modal frequencies, modal displacements and frequency response functions. However, specific numerical standards for model acceptance appear to be limited to modal frequency differences, and the cross-orthogonality between target analysis and test modes. This paper surveys the state-of-the-practice in the U.S. and Europe, and discusses ways in which current practice might be improved.