method and device for focus of expanding waves of a phased array in spherical limited materials

摘要

The present invention relates to a method and apparatus for focusing ultrasonic waves that are propagated from a phased array toward a spherically-bounded object so that they arrive at a pre-selected focal point at the same time and in phase and thereby significantly improve, nondestructively, the detectability of possible flaws in and structural characteristics of the object. The disclosed method comprises calculating the location of a plurality of preferred refraction points on a surface of the spherical work piece using an iterative process. Each of the preferred refraction points correspond to one of the elements of the phased array mechanism. The locations of the preferred refraction points depends upon the location of the pre-selected focal point and the locations of the phase elements. After the preferred refraction points are calculated, the method comprises calculating a pulse firing time for each element of the phased array mechanism that relates to the relative timing of the emitted waves from the elements.