Shake Table Tests on a Scaled Masonry Building: Performance Comparison of Various MEMS Accelerometers for SHM

This study presents the results of an experimental investigation conducted on a 2:3 scale model of a two-storey stone masonry building. We tested the model on the UniKORE L.E.D.A. lab shake table, simulating the Mw 6.3 earthquake ground motion that struck L’Aquila, Italy, on April 06, 2009, with progressively increasing peak acceleration levels. We installed a network of accelerometric sensors on the model to capture its structural behaviour under seismic excitation. Medium- to lower-cost MEMS accelerometers (Classes A and B) were compared with traditional piezoelectric sensors commonly used in Structural Health Monitoring (SHM). The experiment assessed the structural performance and damage progression of masonry buildings subjected to realistic earthquake inputs. Additionally, the collected data provided valuable insights into the effectiveness of different sensor types and configurations in detecting key vibrational and failure patterns. All the sensors were able to accurately measure the dynamic response during seismic excitation. However, not all of them were suitable for Operational Modal Analysis (OMA) in noisy environments, where their self-noise represents a crucial factor. This suggests that the self-noise of the MEMS accelerometers must be less than 1 µg/√Hz, or preferably below 0.5 µg/√Hz, to obtain good results from the OMA analysis. Therefore, we recommend ultra-low-noise sensors for detecting differences in structural behaviour before and after seismic events. Our findings provide valuable insights into the seismic vulnerability of masonry structures and effectiveness of sensors in detecting damage. The management of buildings in earthquake-prone areas can benefit from these specifications.