Traditional linear Lamb wave damage monitoring method is less sensitive to small injury

which limits application and development of structural health monitoring technology of Lamb wave. On the basis of analysis on nonlinear Lamb wave propagation mechanism and nonlinear Lamb wave character parameter extraction method

the experimental research on structure fatigue damage monitoring mechanism of nonlinear Lamb wave is conducted.Experimental verification on T6061 aluminum plates show that the nonlinear Lamb wave character parameters on early micro damage such as structure fatigue has good sensitivity

and nonlinear parameters and damage degree exists same change trend. This provides feasible ideas for warning and assessment for early damage such as metal structure fatigue.