Ultrasonic testing of missing styrofoam in the bottom corner of honeycomb sandwich structure

The defects of the missing styrofoam often occur in the co-cured honeycomb sandwich structure. In the experiment, an ultrasonic focusing probe with a customized wedge was used to detect the reference block with artificial defects. The results show that the ultrasonic wave signal of the defects was obvious, and such defects could be accurately identified by the mehtod.