Free vibration of a cracked double-beam carrying a concentrated mass

Abstract

This paper presents the free vibration of a cracked double-beam carrying a concentrated mass located at an arbitrary position. The double-beam consisting of two different simply supported beams connected by an elastic medium is modelled by using finite element method. The influence of the concentrated mass on the frequencies and mode shapes is investigated. The relationship between the natural frequency and the location of concentrated mass is established and related to the mode shapes. The numerical simulations show that when there is a crack, the frequency of the double-beam changes sharply when the concentrated mass is located close to the crack position. This sharp change can be amplified by wavelet transform and this is useful for crack detection. The crack location can be determined by the location of peaks in the wavelet transform of the relationship between frequency and mass location.

Application of Roving Mass Technique Associated with Wavelet Transform to Structural Damage Detection and Localization

“…The change in the structural stiffness due to the existence of damage in the beam may not be so evident. Therefore, in this research, the Wavelet Transform is used to help in the process of locating possible stiffness changes due to damages (Rizos, Aspragathos and Dimarogonas, 1990;Mermetas and Erol, 2001;Kotambkar, 2014;Khoa and Quang, 2016). This research also presents experimental tests results on steel beams with simulated damages.…”