On Raleigh Equation and Accuracy of its Real Roots Calculations

Abstract

Composite materials require adequate means of nondestructive testing, evaluation, and monitoring. Ultrasonic methods and tools are one means to meet these objectives. The latest advances of electrical and electronic engineering and nondestructive testing methods provide the foundation for a wide class of modern ultrasonic equipment. However, some recent experimental results require reevaluation of existing basic theories, especially in the field of acoustic wave propagation. More accurate calculations of the real roots of the Rayleigh equation with their value approximations by different polynomials given in this paper may be useful for improvement of nondestructive testing of materials. This work also considers additional roots of the Rayleigh equation as a basis for new types of surface waves.