Operational Modal Analysis and Continuous Dynamic Monitoring of Metal Roofing Panel

The metal roofing system is widely used in the platform canopy of the high-speed railway. When metal roofing blows off under strong wind, the blown off roofing can interface with normal operation of high-speed train. Therefore, it is vital important to propose an efficient method to detect the early abnormal behavior of the metal roofing system. In this paper, the operational modal analysis is firstly performed on a scaled model of the metal roofing system, and the first four order modal parameters are estimated. Subsequently, an aluminum clip linking the panel and purlin is removed to simulate the slightly change of the boundary condition. However, it is observed that the modal frequency is insensitive with such an early structural change. Afterwards, a continuous dynamic monitoring campaign is developed to investigate the temperature effect on the modal frequency. It is found that the fundamental frequency is negatively correlated with temperature during a day. The temperature varying from 20 to 60 degrees Celsius results in the frequency fluctuation within 0.2Hz.