Figure 10

Comparison between numerical FEM predictions and measurements for the structure after using both the perturbational solution (for the domain 0 ≤ L ≤ a/4) and numerical optimization (for the domain a/4<L ≤ a/2). The optimization was assisted by the perturbational solution of equation (32) as a starting point. It is seen that the deviation over most of the domain is now within 1% only, with the worst deviation around the a/2 end now within 2% (compared to 4% in Fig. 9 when using PT alone).