Excitation of guided wave modes in arbitrary cross-section structures by applied surface tractions

Abstract

Abstract To assure the integrity and safety of truss structures, much work has been done for inspection in bars using ultrasonic guided waves methods. Guided waves have been widely used for Non-Destructive Testing (NDT) and Structural Health Monitoring (SHM) because of their long propagation distance and reliable responses. Though good for assessment of guided wave in the regular section structures such as cylinders, pipes and rails, the excitation of guided wave modes in irregular bars lack further research due to the arbitrary cross-section. This paper presents the excitation and propagation of guided waves in arbitrary cross-section structures by coupling the normal mode expansion (NME) method with the semi-analytical finite element (SAFE) method. Then, a Tee-bar example of finite element (FE) simulations is performed to validate the proposed SAFE-NME method. Moreover, the validated method is used to develop a double mode inspection strategy for multi-damages identification, showing the potential for NDT & SHM applications.