Sound fields radiated from a linear phased array based on analytical solutions of transient elastic waves

Beam characteristics of a linear phased array transducer are critical to its engineering applications as well as to its design. This paper proposes a method for the theoretical calculation of ultrasound field radiated by a linear phased array coupled to an elastic solid by a longitudinal wave couplant. In this case, the ultrasound field can be determined by superposition of the exact and analytical solutions of transient elastic waves induced by a number of discrete line sources normally acting on an elastic half-space. Based on the theoretical calculation, this work investigated the influences of several important parameters in a linear array transducer, such as wave length, array size, ratio of element width to inter-element spacing, to the ultrasound field characteristics. Interesting phenomena and useful results are obtained, which provide fast and accurate guidance for linear phased array transducer design. It also satisfies diverse and specific demands for actual engineering testing using arrayed transducers.