title: Modeling the quasicompressional wave field of a rectangular transducer in a transversely isotropic solid.
abstract: A fast model for simulating the transient quasicompressional wave field of a rectangular ultrasonic transducer directly coupled to a transversely isotropic elastic half-space of general orientation is developed. The so-called two-tier asymptotic approach and the uniform stationary phase method are used to derive the high-frequency asymptotics of time-harmonic displacements. Then, transient fields are modeled by means of harmonic synthesis. In geometrical regions, the formulas involve elementary and inside boundary layers, well-known special functions (Fresnel integral and generalized Fresnel integral), and are applicable in the radiating near field. The asymptotics elucidate the physics in terms of various arrivals and give explicit dependence of the radiated waves upon model parameters. The asymptotic code is tested against a direct numerical solution. It is at least a thousand times faster but describes accurately both arrival times and amplitudes of various pulses radiated by the transducer.
authors.affiliation: Centre for Waves and Fields, School of Engineering, South Bank University, 103 Borough Road, London SE1 0AA, United Kingdom. d.gridin@ic.ac.uk
authors.forename: Dmitri
authors.initials: D
authors.lastname: Gridin
mesh_terms: D016880:Anisotropy; D008962:Models, Theoretical; D014159:Transducers; D014465:Ultrasonics