Excitation design for damage detection using iterative adjoint-based optimization—Part 2: Experimental demonstration

The iterative, adjoint-based excitation optimization technique developed in Part 1 is evaluated on an experimental structure consisting of a non-linear cantilever beam. The developed technique is shown to be effective at producing excitations which significantly improve the detectability of damage relative to two different “naive” excitations (a random input and a chirp). The technique is also demonstrated to be effective across multiple damage levels. In addition, by formulating a second-order version of the adjoint problem, it is shown that the terms needed to solve the associated adjoint equation are readily available from many commercially available finite element packages, which further enhances the usability of the technique.