Structural damage detection using PCA method under varying operational condition

Great attention has been paid to researches on structural damage detection using structural vibration characteristics. Using the online measured structural vibration responses to identify and monitor structural damage is one of the important ways to insure reliable operation and to reduce maintenance cost of in-service structures. One of the main obstacles for deploying a monitoring system on-site is the enviromnental and operational variation of structures. Often the so-called damage-sensitive features employed in these damage detection techniques are also sensitive to changes of the environmental and operational conditions of the structures. This paper presents an application of principal component analysis (PCA) for damage detection in order to effectively eliminate operational effect from the health system with natural frequencies being taken as damage features. The ASCE structural health monitoring benchmark problem with normal operational mass variation is considered for such a purpose. Simulation results demonstrate the effectiveness of the proposed method.