Operational modal analysis for structural health monitoring

The dynamic properties of super-tall buildings have been well studied but the low-rise and moderate-high buildings do not attract enough attention. The project presented in this paper involves a series of ambient vibration tests and Operational Modal Analysis (OMA) for low-rise and moderate-high buildings. The purpose is to develop a database for the dynamic properties of this type of buildings and finally conduct Structural Health Monitoring (SHM) for these buildings. Ambient vibration tests and OMA were conducted for 2 representative buildings. Because the number of sensors was limited, in order to obtain detailed mode shapes multiple setups of measurement were carried out for each building, with each setup covering one portion of the building. Common locations were measured between each two successive setups such that the partial mode shapes from different setups could be assembled to global mode shapes. The identified modal frequencies, modal damping ratios and mode shapes reveal interesting dynamic behaviors of the buildings.