2021 Volume 77 Issue 2 Pages I_69-I_79
This paper presents a 3-D elastodynamic time-reversal method using the topological sensitivity for the defect detection indicator in order to determine the number and position of defects in an elastic solid. The time-reversal method has been developed as one of the inverse scattering techniques in the field of the ultrasonic non-destructive evaluation and earthquake seismology. However, in general, it is difficult to quantitatively evaluate the convergence positions of the time-reversal waves in time-domain. The authors et al. have been studying the reconstruction of defect shape by utilizing the topology sensitivity for the calculation of the time-reversal method for scalar wave problems and 2-D elastodynamic problems. In this research, we extend the previous researches for such problems to 3-D elastodynamic problems., The convolution quadrature time-domain boundary element method (CQBEM) for 3-D elastodynamics is utilized to calculation 3-D elastodynamic wave fields. As numerical examples, some defect detection results are demonstrated to investigate the performance of the present method.
