14. Roadmap for a Highly Improved Modal Test Process

Difficulties encountered in modal test planning and recent advances in experimental modal analysis of aerospace systems have resulted in a new paradigm for experimental modal analysis. The Simultaneous Frequency Domain (SFD) method, weighted complex linear least squares correlation methodology, and state space model left- and right- hand eigenvector properties combine to produce the following benefits that are independent of an explicit TAM mass matrix: (1) verification and validation of experimental modes via isolation of individual experimental modes, (2) automatic self- orthogonality of experimental modes, (3) test- FEM cross orthogonality, and (4) experimental complex mode kinetic energy distribution. The new approach directly employs complex experimental modes (rather than real mode approximations) and frees experimental data from a potentially flawed TAM mass matrix. A roadmap for incorporation of the new paradigm into NASA and USAF standards and continued progress are outlined in this paper.