Full matrix focusing method has been proved with the advantages of good signal-to-noise ratio and high-resolution image. However, it is still suffering from the problems of the time-consuming data acquisition and processing. In order to solve the problem, two kind simplified matrix focusing methods are provided in this paper. One is a triangular matrix focusing algorithm based on the principle of reciprocity for the multi-channel ultrasonic system. The other is a trapezoidal matrix focusing algorithm based on the energy weight of the different channel to the imaging area. In order to prove the validity of the provided algorithms, both side-drilled hole and oblique crack defects are used for the imaging comparation. The results show that the imaging quality of the triangular matrix focusing algorithm is basically consistent to that of the full matrix focusing method, and the imaging quality of the trapezoidal matrix focusing algorithm can be slightly reduced as the amount of multi-channel data decreases. In addition, both data acquisition and computational efficiency using the provided algorithms have been improved significantly.

Full matrix focusing method of ultrasonic phased array has been proved with advantages of good signal-to-noise ratio and imaging resolution in the field of Ultrasonic NDT. However, it is still suffering from the time-consuming data acquisition and processing. In order to solve the problem, two simplified matrix focusing methods are provided in the paper. One provided method is a triangular matrix focusing algorithm based on the principle of reciprocity for the multi-channel ultrasonic system. The other provided method is a trapezoidal matrix focusing algorithm based on the energy weight of the different channel to the focusing area. Time of data acquisition and computational is decreased with the provided simplified matrix focusing methods. In order to prove the validity of two provided algorithms, both side-drilled holes and oblique cracks are used for imaging experiments. The experimental results show that the imaging quality of the triangular matrix focusing algorithm is basically consistent to that of the full matrix focusing method. And imaging quality of the trapezoidal matrix focusing algorithm is slightly reduced with the amount of multi-channel data decreasing. Both data acquisition and computational efficiency using the triangular matrix focusing algorithm and the trapezoidal matrix focusing algorithm have been improved significantly compared with original full matrix focusing method.