Dynamic response of masonry structures to temperature variations: experimental investigation of a brick masonry wall

Structural health monitoring (SHM) is essential for preserving historical and modern infrastructure by tracking dynamic properties such as frequencies and mode shapes. Changes in these properties can indicate structural damage, but environmental factors like temperature can also cause similar variations, complicating damage detection. This study investigates from an experimental point of view the effect of temperature on the dynamic behaviour of masonry structures, focusing on a masonry wall subjected to thermal load variations within operational conditions. The experimental setup involved a masonry wall specimen tested at the Structural Laboratory of the University of Minho, Portugal. The mock-up was subjected to various boundary conditions and loading scenarios. The results showed that the natural frequencies of the masonry wall can be significantly influenced by temperature changes, variations strictly related to the boundary conditions and the stress acting on the mock-up. In contrast, mode shapes seem not to be affected by temperature variations. This study provides valuable insights into the temperature-induced variations in the dynamic properties of masonry structures, emphasising the need to consider environmental effects in SHM applications. By filtering out these environmental influences, more accurate damage detection and proactive maintenance strategies can be developed, enhancing the safety and longevity of both historical and modern structures.