Characterization of Concrete Hole Defects by Ultrasonic Finite Amplitude Method

The finite amplitude method is a nonlinear ultrasonic technique that uses the relation of higher order ultrasonic harmonics with nonlinear parameters of damaged materials and structures for the characterization of material defects, which has been more often used in material microscopic damage diagnostics. The finite amplitude method is used in detecting concrete with different sizes of holes. The results show that the nonlinear parameter can sensitively reflect the extent of the hole defect.