Parameters Tuning of TFM and Defect Detection of CFRP Sheet Based on Ultrasonic Array Probe

Carbon fiber-reinforced plastics (CFRP) becomes wildly used while easily delaminated during manufacture and use, thus it is important to detect those delamination defects. This paper aims to provide an effective method to detect small delamination defects in CFRP sheets, and Total Focusing Method (TFM) holds the trend of development in the testing field. In order to improve the imaging effect, several parameters of TFM including excitation signal length, time-delay matrix, characteristic value and weight function of superimposed echo signals are analyzed and tuned, and then simulations and experiments are performed to verify the validity of the parameters tuning.