Abstract
This paper is concerned with 3-D inverse scattering analysis for a spherical cavity in a viscoelastic solid. In recent years, polymer and composite materials have been developed for various uses and applied to
aerospace and civil engineering structures. Therefore, it is desirable to develop a defect detection method for polymer and composite materials by using ultrasonic non-destructive testing which is widely used in various engineering fields. Since the stress and strain of polymer and composite materials have time-dependency, the viscoelastic property must be considered. Therefore, it is required to develop a forward analysis technique to understand the ultrasonic wave propagation behaviors for defects and an inverse analysis technique to reconstruct the size and shape of defects in a viscoelastic solid. The forward analysis technique in time domain has already been developed by our group. On the other hand, the inverse scattering technique based on Born approximation for a defect in a viscoelastic solid has not been developed yet. Therefore, in this research, a 3-D inverse scattering technique is developed for the reconstruction of a spherical cavity in a viscoelastic solid. Some numerical results are demonstrated to verify the developed inverse scattering technique by reconstructing size and shape of a spherical cavity in a viscoelastic solid.
