AE source location of debonding steel-rod inserted and adhered inside rubber

Abstract

Rubber bearings have been applied worldwide to bridge and building components. However, it comes out a critical issue, since significant amounts of damage and deterioration of the bearings have been reported. Therefore, the authors attempted an experimental study on damage evaluation of rubber bearings, by using acoustic emission (AE) method. In the case, it was found that the velocity of the elastic-wave propagating inside the rubber was slower than those of concrete, steel, and other rigid materials. As a result, one question remains on the location accuracy, where AE sources are generated inside the rubber.In order to clarify an applicability of AE method to damage evaluation of rubber bearings, experimental research was conducted. A steel rod was inserted in a rubber specimen and the tip of the rod was adhered. Then, debonding of the rod was measured with a pull-out test. Even distances from the tip of the steel rod to the rubber surface were investigated. Two types of AE sensors were used, with resonances at 60 kHz and 150 kHz. A three-dimensional location analysis was performed by AE method to identify debonded locations. Thus, both applicability and accuracy of AE method in the rubber bearings are verified, and a good promise to evaluate the damage in the rubber bearings is confirmed.