Total Fatigue Life In Structural Health Monitoring

The monitoring and evaluation of structural fatigue damage has become a significant problem to be studied. The fatigue life gage is a perfect sensor in monitoring cumulative fatigue damage. The characteristic of fatigue life gage is studied and the fatigue response model is proposed, substantive progress in the application of the sensor.This paper is based on 863-high-tech project (Study on fatigue life gage be used in platform health monitoring). Proposing a new method to apply the fatigue life gage on the structure health monitoring and making some research works in this field, the main points are summarized as follows:1) The performance of the fatigue life gauge is studied, including the characteristic calibration curve and response character, the mechanism of electrical resistance, manufacturing technique and application.2) Based on the date of constant loading, the rule of variable- amplitude loading was obtained. The experimental results and calculations are compared and analyzed, the results denote that the program is feasible.3) On the basis of probability statistical theory, dispersibility of resistance change of fatigue life gage be analyzed and the calculating method of the dispersibility is set up.4) The methodology and strategy for life analysis with structural health monitoring data has applied to the Tsing Ma Bridge, the relevant relation between increased resistance and load spectrum was obtained. On the basis of increased resistance, get the load of the bridge and calculate its residual life. The result is satisfied.