Field Tests of Bridge Damage Detection by Using the Passive Tap-Scan Method

In recent years, using a passing vehicle to detect damage has attracted extensive attention. Among these works, the tap-scan damage detection method can achieve a high signal to noise ratio by applying the tapping force at a sensitive frequency that is higher than the frequency band of environmental noises. Further analysis shows that this method can detect the stiffness transition of beam structures, because the vehicle acceleration is very sensitive to the stiffness gradient. This paper will further report the new design of the passive tap-scan damage detection vehicle updated for practical implementations. The results from two field tests are used to demonstrate that this vehicle can not only find the damage on beam surface, but also give the quantitative estimation of damage severity. All these findings demonstrate the practical potential of the passive tap-scan method.