A linear least-squares version of the algorithm of mode isolation for identifying modal properties. Part I: Conceptual development

Abstract

The Algorithm of Mode Isolation (AMI) is an iterative procedure for identifying the number of modes contributing to a frequency response function (FRF) concurrently with identifying the complex eigenvalues and eigenvectors of those modes. The latest modifications obtain these modal properties solely by using linear least squares fits of the FRF data to canonical forms. The algorithmic operations are explained in a detailed sequence of steps that are illustrated by some sample data. The computational efficiency of AMI relative to other modal identification algorithms that fit response data to multi-degree-of-freedom model equations is discussed.