Structural damage localization with tolerance to large time synchronization errors in WSNs

With recent technological advances in smart sensor platforms, structural condition monitoring implementations based on Wireless Sensor Networks (WSNs) have received considerable attention. Modal identification is an integral step in many structural condition monitoring systems. However, accurate time synchronization is not always possible, leading to incorrect identification of the mode shapes. Although strict time synchronization of the wireless sensors has been viewed as crucial for the identification of mode shapes, a new perspective is taken herein. The distortion in the identified mode shapes is characterized and accommodated. Then the resulting mode shapes are used with a flexibility-based damage detection approach to localize damage to the exact elements. Numerical simulations considering a simply supported beam are used to demonstrate that the requirement of frequent sensor synchronization can be relaxed with this approach, without sacrificing accuracy in the results.