Abstract
In this paper, we develop a damage identification method for one-dimensional lumped structures based on the measurement of traveling waves excited by ambient loads. First, the waves going forward and backward through a certain point on the structure are measured using a sensor array. The dispersion equation of the one-dimensional waveguide gives a traveling wave decomposition scheme in the frequency domain. Then, the wave transfer functions, which describe the correlation between the in-coming and out-going traveling waves at the boundary of a certain region of the structure, are identified. Since the characteristic impedance of the traveling wave is sensitive even to the local damage in early-stage, the wave transfer function may change significantly as the damage progresses. Numerical examples show that the proposed method is capable to detect the existence and the position of the early damages only using a couple of sensors.
