Active lamb wave based crack monitoring and evaluation using projection of reflection field

Monitoring and evaluation of damage were one of the hot issues in structural health monitoring. Lamb wave based crack damage monitoring and evaluation method was proposed by using projection of reflection field. Propagation, reflection and scattering of endpoints of Lamb waves were analyzed firstly. Linear sensor array was adopted to capture and rebuild the projection of damage reflection field onto the array based on the reflection and scattering discipline of monitoring waves at the crack. The length of the crack could be evaluated by calculating the distance between the peaks in the rebuilt field. The experimental results show that the proposed method can realize the evaluation of the length of crack damage, and provide a way for the online monitoring of crack propagation.