The success of guided wave-based structural health monitoring (SHM) systems substantially relies on the effective design of sensing array as well as the insightful interpretation of active sensing signals. However, identifying the optimum design parameters, such as transducer dimensions, interrogating frequency, preferable wave mode, and sensing locations, is a challenging task. In addition, the multimodal, dispersive nature of guided waves as well as their complex interaction dynamics with structural features and damage further give rise to the difficulty of properly analyzing the sensing signals. Thus, highly efficient computational models of guided wave-based SHM procedures are of critical importance for both SHM system design and signal interpretation. Several demanding requirements for the computational models can be identified: accuracy for high frequency, short wavelength, long propagating distance waves, efficiency in terms of computational time and computer resources, and versatility to explore a wide range of design parameters such as different material and geometric scenarios. However, commercially available numerical modeling tools that are based on a finite element method (FEM) cannot satisfy all these requirements, as ultrasonic wave propagation in large-scale, complex structures usually results in a computationally prohibitive problem.