Damage identification using temperature-driven SHM

Temperature-driven structural health monitoring (SHM) of bridge structures has progressed over the past several years due to its advantages over other conventional forms of monitoring. The concept for temperature-driven evaluation utilizes thermal inputs as excitations to the structural system. Therefore, data acquisition of these excitations, along with the corresponding responses (e.g. strains or displacements), allows for identification of unique signatures (or baselines) of the structure. Some of the logistical advantages of temperature-driven SHM are the large measurement signal-to-noise ratios, minimal data storage and time synchronization requirements, and relatively inexpensive equipment. However, research has indicated the biggest advantage is the sensitivity of temperature-driven signatures to realistic structural changes, potentially as a result of damage. Recently, a long-span cantilever truss bridge has been instrumented with a temperature-driven monitoring system that includes localized temperature, strain, and displacement measurements. A numerical study of the structure is presented, which evaluates the sensitivity of the SHM system to realistic damage scenarios.