Nonlinear Lamb wave for the assessment of ratcheting behavior in IF steel

This work demonstrates the use of nonlinear Lamb wave for characterizing the ratcheting behavior in interstitial free (IF) steel. Lamb wave has been used to measure the generated second harmonic component during ratcheting fatigue. A pair of wedge transducers is used to generate and detect the fundamental and second harmonic component of Lamb wave at various interruption of damage and correlation is made with nonlinear ultrasonic parameter. It is seen that acoustic nonlinear parameter evaluated using Lamb wave is very much sensitive to plasticity that has been induced during ratcheting.