Figures & data
Figure 1 Plane wave insonification of an isotropic cylinder.
Figure 2 Experimental setup.
Figure 3 Flowchart of the inversion algorithm.
Table 1. Material properties of steel cylinders.
Figure 4 A typical backscattered echo from a steel cylinder made from Mat. 1.
Figure 5 Experimental form function for Mat. 1 at normal incidence.
Figure 6 Experimental form function for Mat. 2 at normal incidence.
Figure 7 Experimental form function for Mat. 3 at normal incidence.
Table 2. Resonances of steel cylinders.
Table 3. Calculated wave velocities of steel cylinders by using the simplex and GAs.
Table 4. Calculated wave velocities, percentage of error and number of iterations by using GA and considering different number of experimental resonances, Mat. 1.
Table 5. Calculated wave velocities, percentage of error and number of iterations by using simplex method and considering different number of experimental resonances, Mat. 1.
Figure 8 Change in longitudinal wave velocity by number of iterations using GA for Mat. 1.
Figure 9 Change in shear wave velocity by number of iterations using GA for Mat. 1.
Figure 10 Convergence behaviour of simplex method for Mat. 1, blue triangles are initial guesses.
Figure 11 Convergence zone for Mat. 1 using simplex method. Initial values leading to divergence are marked by a cross (×) and the area confined by cross signs is the convergence zone.
Figure 12 Comparison between experimental and calculated form functions for Mat. 1.
Figure 13 Comparison between experimental and calculated form functions for Mat. 2.
Figure 14 Comparison between experimental and calculated form functions for Mat. 3.
