## 1 Introduction  
Laminated composite materials are extensively used in various engineering fields such as the aerospace industry, land-vehicle manufacturing, wind and hydrogen power applications, etc. [1; 2; 3; 4]. Among the major advantages of composite materials are their high strength-to-weight ratios and the possibility to achieve oriented mechanical properties, which can be combined to produce a laminate designed for a specific high-performance structure [1; 5; 6]. However, damage may still occur in such materials, which makes them an important object for emerging non-destructive testing (NDT) [7] and structural health monitoring (SHM) [8] techniques, in particular, those utilizing elastic guided waves (EGWs) as a physical basis [9; 10]. Specific wave phenomena underlying EGW-based NDT/SHM techniques are including (but, of course, not limited to) EGW excitation with either contact or non-contact techniques, their propagation through or along the object, possible scattering by structural components and/or occurring damage and corresponding wave motion detection employing various sensing technologies [7; 8; 9; 10]. Development of efficient ultrasonic wave-based diagnostic strategies adopted for composite structures requires a thorough understanding of the of elastodynamic behavior of such materials [11; 12; 13; 14]. Prior extensive theoretical studies allow for the optimization of NDT/SHM system performance and enhance their damage detection and characterization capabilities [15; 16; 17; 18; 19]. For the numerical simulation of the elastodynamic behavior of laminated composite structures, various computational techniques have been widely adopted [20], among which mesh-based methods, especially the finite element method (FEM) and its modifications, play an important role [21; 22]. When a multi-layered elastic structure is discretized with the standard FEM, e.g., employing various open-source or commercially available codes [23], at least one finite element is required within the sub-layer thickness. Therefore, computational costs are growing dramatically compared to conventional metallic structures when laminated composites are simulated, especially for three-dimensional problems [23; 24]. To overcome this burden, several strategies are adopted. They include the application of more sophisticated FEM algorithms, e.g., the spectral element method [25]. Relying on the specific approximation functions, it is especially beneficial for the simulation of wave propagation problems in the time domain [26]. Another alternative is to adopt approximate plate or shell theories, where the dependency of strains and displacements in the vertical direction is resolved analytically, thus reducing the model dimension by one order [27], or approximated in a more simple way than in complete 3D models [28; 29]. For relatively thick composites, especially those where certain periodicity exists in stacking sequence, the whole laminate could be replaced by a single anisotropic layer [30; 31]. Its effective elastic properties are obtained by employing either static [31; 32] or dynamic [33] homogenization approaches. The adequacy and efficacy of such approaches considering the evaluation of EGW phenomena in various composites have been studied in Ref. [34; 35]. For instance, a comparison of the static effective medium model with the exact multi-layered model for non-symmetric cross-ply laminates showed that this approximation provides similar results if the number of plies is quite large. Otherwise, it is adequate only for fundamental EGW modes at low frequencies. Such results were obtained both for phase velocity dispersion curves of fundamental and higher-order EGWs and for transient in-plane wave propagation excited by a line source.