Abstract:
In the laboratory environment, using acoustic emission(AE) technique to monitor the fatigue crack growth process of steel tower commonly used in steel Q345B. Test results show that, there is a good corresponding relationship between the three stages of the cumulative count of acoustic emission and the three stages of the description of the fracture mechanics, the whole process can be well characterized, through the analysis of test data, it is proved that AE signal has the property of fatigue warning; For the first time to put forward the fatigue damage process characterized by the average counts within a period of time Δ
C/Δ
N, can effectively overcome the large dispersion of data, the material failure is not easy to judge the faults of counting rate,it is more convenient to early warning fatigue fracture, in order to provide the basis for acoustic emission monitoring and early warning pattern recognition. At the same time in the second stage of cumulative fatigue damage, the logarithm value of the average counts within a period of time Δ
C/Δ
N and intensity factor amplitude Δ
K exist the apparent ground relation,can provide the basis for the monitoring and early warning of fatigue crack growth of Q345B.