Guided Wave Excitation and Sensing in Constant Irregular Cross Section Structures with the Semianalytical Finite-Element Method

Guided waves play an important role in practical structural health monitoring (SHM) systems. Due to the complexity of irregular cross sections, there has been little research on guided wave modal control done using excitation and sensing distribution models. In this paper, the semianalytical finite-element (SAFE) method for the quick and reliable solution of guided wave excitation and sensing in irregular cross sections is developed, and modal control method is proposed by optimal transducer design. The free-vibration and forced solutions to a pin-force excitation in an I-type bar are determined up to a frequency of 150 kHz. The effects of four loading and sensing cases are discussed, and the time–transient responses of four cases are calculated. The maximization of the signal amplitude of the desired modal signal and the suppression of other modes can be achieved with different excitation and sensing distributions. The experimental investigation of an I-type bar is shown to validate the reasonability of the modal control method. Finally, a feasible optimal and economical excitation/sensing transducer design method is presented and discussed.