Complex Notation in Flutter Analysis

Abstract

Flutter analysis in aircraft or bridge engineering has to include motion-induced aerodynamic forces. These forces are mathematically described in two equivalent ways, namely, by real number or complex number expressions. Accordingly, flutter analysis can be performed using either real or complex arithmetic. At first glance, the use of either kind of notation seems to be more a question of personal preference, as both lead to the same numerical results. Nevertheless, this paper attempts to advocate the use of complex notation both in aircraft and bridge flutter analysis. Real-number and complex-number descriptions of the same mechanical phenomena are compared. It is shown that, apart from computational advantages, complex notation leads to mathematically more compact and more elegant expressions, which is of significance particularly from an educational standpoint.