Design and Development of In Situ Fatigue Sensors for Structural Health Monitoring of Highway Bridges

Abstract

Initial development work for an in situ fatigue sensor for the detection of fatigue damage in steel bridge structures is presented. The in situ fatigue sensor is designed to be bonded to the base structure and is based on the strain-life fatigue analysis method. Sensors are constructed of electrically conductive material with notched sensor arms producing varying stress concentration factors. The sensor operates on the principle of predictable progressive failure of the parallel arms as fatigue damage is accumulated in the base structure. Experimental results of the behavior of the fatigue sensor under constant amplitude loading of a base structure-mimicking carrier specimen are compared with the simulation results obtained by the finite-element analysis method and show reasonable agreement.