The main objective of the work reported in this monograph is the fabrication of an experimental apparatus to detect slowly evolving anomalies (i.e., decrease in stiffness due to fatigue failure) in complex mechanical systems at an early stage by observing time series data of the available ultrasonic and performance measuring sensors. The information on evolving anomaly will serve as an input to the life extending control policy that will, in turn, generate corrective actions to mitigate fatigue crack damage in the specimen structures and thereby extend the remaining life of the system without any significant loss in performance. The monograph presents the design requirements for the experimental testbed. Physical modeling gives out the expected resonant frequencies. Finally, system identification presents the actual resonant frequencies achieved from the setup and compares the same with the theoretical physical model. The monograph discusses the proximity of the resonant frequencies achieved through physical modeling and system identification and presents conclusions on the same.