Benchmark Studies For Structural Health Monitoring Using Analytical And Experimental Models

The latest bridge inventory report for the United States indicates that 25% of the highway bridges are structurally deficient or functionally obsolete. With such a large number of bridges in this condition, safety and serviceability concerns become increasingly relevant along with the associated increase in user costs and delays. Biennial inspections have proven subjective and need to be coupled with standardized non-destructive testing methods to accurately assess a bridge’s condition for decision making purposes. Structural health monitoring is typically used to track and evaluate performance, symptoms of operational incidents, anomalies due to deterioration and damage during regular operation as well as after an extreme event. Dynamic testing and analysis are concepts widely used for health monitoring of existing structures. Successful health monitoring applications on real structures can be achieved by integrating experimental, analytical and information technologies on real life, operating structures. Real-life investigations must be backed up by laboratory benchmark studies. In addition, laboratory benchmark studies are critical for validating theory, concepts, and new technologies as well as creating a collaborative environment between different researchers. To implement structural health monitoring methods and technologies, a physical bridge model was developed in the UCF structures laboratory as part of this thesis research. In this study, the development and testing of the bridge model are discussed after a literature review of physical models. Different aspects of model development, with respect to the physical bridge model are outlined in terms of design considerations, instrumentation, finite element modeling, and simulating damage scenarios. Examples of promising damage detection methods were iii evaluated for common damage scenarios simulated on the numerical and physical models. These promising damage indices were applied and directly compared for the same experimental and numerical tests. To assess the simulated damage, indices such as modal flexibility and curvature were applied using mechanics and structural dynamics theory. Damage indices based on modal flexibility were observed to be promising as one of the primary indicators of damage that can be monitored over the service life of a structure. Finally, this thesis study will serve an international effort that has been initiated to explore bridge health monitoring methodologies under the auspices of International Association for Bridge Maintenance and Safety (IABMAS). The data generated in this thesis research will be made available to researchers as well as practitioners in the broad field of structural health monitoring through several national and international societies, associations and committees such as American Society of Civil Engineers (ASCE) Dynamics Committee, and the newly formed ASCE Structural Health Monitoring and Control Committee.