A convergence formula for sound transmission loss of composite laminates based on three different shear deformation theories

The analysis of Sound Transmission Loss (STL) for composite laminates based on Classical Plate Theory (CPT), First-order Shear Deformation Theory (FSDT), and Third-order Shear Deformation Theory (TSDT) has been widely applied. However, in the process of conducting sound transmission loss, there are no accurate criteria and formulas available for determining its convergence criterion. The current method for determining convergence is based on several typical frequencies to judge the convergence across the entire frequency range, leading to inaccurate results in the high-frequency region. In this paper, a new convergence criterion and formula are developed based on CPT, FSDT, and TSDT. These can be directly applied to determine the convergence of the sound transmission loss calculation process for composite laminates, suitable for truncated iteration of sound transmission loss across all frequency ranges.