Structural damage detection using the Modal Correlation Coefficient (MCC)

Since its introduction by Allemang and Brown in 1982 [1], the Modal Assurance Criterion (MAC) has been the main quantitative measure of correlation for mode shapes because it is a simple yet capable means of numerically expressing the similarity or difference between two mode shapes. In 1996, the Modal Correlation Coefficient (MCC) which is a modification of the MAC was introduced [2]. The new measure was devised for damage detection applications, structural health monitoring, and diagnostics. In this paper, the properties of MCC are discussed and its sensitivity to spatial resolution is studied. Several examples are given to illustrate its capabilities and to show how it maintains the simplicity and orthogonality of the standard MAC. Also, the paper shows how damage can be detected using MCC even if the accompanied magnitude changes are minimal.