Research Of The Ultrasonic Beam Formation Based On The Principle Of Lowest Energy

Ultrasonic phased array technique is one of the research hotpot in the field of ultrasonic testing. Phased array consists of a series of piezoelectric chip array. Using electric excitation circuit whose phase can be precisely controlled to drive each array to launch ultrasonic wave. The ultrasonic be launched by each array in space interfere to form sonic beam. The beam will produce the reflected wave when it meet the interface with different acoustic resistance in space. The reflected wave can be received by receiving equipment, then form to beam, finally form complete waveform figure, and to judge whether there are defects in the material. The measurement technology is easy to control, high accuracy, it develop quickly in the fields of medical and industrial.In order to have some understanding of measurement, this paper firstly introduces the basic knowledge of phased array measurement and the principle of measurement. Based on this, the delay time of phased array is stressed. The delay time of phased array related to the effective of ultrasonic focus and deflection in the space. Therefore, it is very important to research delay time.Based on the different characteristics of ultrasonic wave when spread in space, research delay-time under two kinds of circumstances. Studying the paths of ultrasonic wave and calculating the delay time. Because of the sonic path relatively simple, delay time can be counted by geometric method.In the second part mainly research the characteristics and the calculation of Sonic.The path of sonic will change when passing from one medium to another. In such cases, delay time calculation will become very complex. Finding the equation of delay time based on Neil theorem and Fee horse principle.But the equation is very complicated and hard to solve. Finally we had to use a computer to solve. Writing out a MFC interface by VisualC++6.0...