Modal Testing and System identification of a three story steel frame
Abstract »Structural Health Monitoring plays a vital role in assessing in-situ the performance of a structure. There are several techniques available for System Identification and Damage Detection. Structural health monitoring based on the vibration of structures has attracted the attention of researchers in many fields such as: civil, aeronautical and mechanical engineering. This paper provides focuses on the state-of-the art methods for modal parameters extraction from modal testing. A three story bookshelf frame has been used for the experimental study and a free vibration test has been conducted. The book shelf frame, made of galvanized steel, has the following dimension: 60 cm width, 27cm depth and 133 cm height. The frame has been instrumented wireless sensors. The wireless sensors used here are tri-axial. Three accelerometers have been installed on each floor of the frame. The real-time monitoring has been performed using the Lab View software. The Frequency Domain Decomposition (FDD) and Stochastic Subspace Identification (SSI) methods have been used here to extract the modal properties from dynamic response. The extracted results from both methods have been compared and they are found to be close to each other.