Mechanical structural health prognosis with nonlinear mixed frequency ultrasonic signal analysis

In order to detect the early fatigue crack of mechanical components simply, this paper puts forward ultrasonic testing technology different side collinear mixing. Firstly, based on nonlinear theory, method calculating difference frequency and sum coefficients mixing is deduced. Then, ram-5000 SINAP system used aluminum alloy specimens with five depth cracks, corresponding spectrum diagram drawn. From experimental results, we get that positively correlated within a certain depth. Finally, by analyzing fitting data, prediction models are established. Through analysis combination above two models, model relative coefficient established, average error three compared. The results show has better results. research work in makes useful exploration for detection prediction.