Sub-aperture virtual source total focus method applied to oblique wedges
Under the wedge oblique incidence detection process,the use of wedges will further reduce the defect detection capability of total focus method(TFM).Especially in the detection of large depth defects and coarse-grained material,the TFM image will have a low signal-to-noise rate due to the decrease in the amplitude of defect feedback.In order to improve the incident energy,a sub-aperture virtual source total focus method(SVS-TFM)is proposed for oblique wedge imaging.The results show that this technique can control the sub-aperture element excitation by time delay to form a virtual source emission,which significantly increases the acoustic energy emitted into the detected component.When the transverse L value is 20-40 mm,the amplitude of Φ3 side drilling in the depth range of 17-38 mm is 4.58-7.12 dB higher than that in the brass full-focusing image.When the transverse L value is 30-40 mm,in the depth range of 40-65 mm,the amplitude of Φ1 side drilling is 0.63-2.35 dB higher than that of carbon steel TFM image.Therefore,this technology is applied to the detection of coarse grain materials under the oblique incidence detection process of wedges,and has a good detection effect.
万方数据
维普
