On detection of damage location of bridges

Using vibration signatures to detect damages of a bridge has been a popular non-destructive evaluation approach. However, conventionally defined modal parameters may not be sufficiently sensitive for many types of bridge damages. Furthermore, typical modal parameters are global parameters, it is difficult to use them to determine the location of damage. In this paper, we present a newly defined modal parameter, the energy transfer ratio (ETR) as a base line signature to detect and locate certain types of damages. Theoretical analysis on ambient test and signature extraction and model bridge test verification are also described. It is shown that using ETR is more superior than other vibration signatures in locating the damages in bridges.