Transient scattering of a plane SH wave by a rough cavity of arbitrary shape embedded in an elastic half-space

Transient scattering of plane SH waves by a corrugated cavity embedded in a 2-D elastic half-space is investigated. The scattered wave field resulting from a steady-state incident wave is determined by using the direct boundary integral equation method. The transient response is constructed from the steady-state solution by using the Fourier synthesis.;Circular and elliptical based rough cavities are examined. Their corrugated surfaces are generated by perturbing the corresponding smooth cavity surface in periodic or random fashions. For the randomly corrugated cavities, both random normal and random uniform distributions are considered. The importance of the cavity shape, the nature of the corrugation (periodic vs. random), the angle of incidence, the location of the observation station, and the predominant period of the incident Ricker wave in the transient scattering of elastic waves are studied in detail.;In general, the half-space surface response clearly detects the cavity corrugation within the near field, i.e. the cavity roughness is apparent essentially above the cavity only. In this region, the cavity roughness for the elliptical models has greater impact on the surface response than the corresponding circular models.;The choice of seed parameter to initiate the generation of the random uniform and random normal perturbation vectors has little effect on the surface motion. Averaging the responses across the seed parameter further indicates that the random normal and random uniform cavities are very similar. Thus the seed parameter averaged random cavity results are combined to form a mean response. Comparison of the surface responses with respect to the corrugation type demonstrates that the periodically corrugated cavity produces a more significant effect on the half-space surface response than randomly corrugated cavities.