Localization of breathing cracks using combination tone nonlinear response

Abstract

In this paper, a new nonlinear combination tone system identification technique is investigated to identify breathing crack damage in isotropic rod structures. Inspired by the combination tone phenomenon observed in the human auditory system, the difference of two harmonic excitation frequencies is utilized to detect and locate the breathing crack. The method of multiple scales is used to analyze a simplified but representative bilinear system and gain insight into the concept. An experimental investigation is performed to verify the proposed approach. Compared to previously introduced techniques for nonlinear system identification of breathing cracks using super-harmonic or sub-harmonic signals, the proposed approach is much more robust and easier to implement.