On the Calculation of Transmissibility Functions for Vibro-Acoustic Finite Element Models
54º Congreso Español de Acústica — Tecniacústica 2023
Abstract
In recent years, the interest in the research of transmissibility functions rose for several applications, like Force Identification, Operational Modal Analysis, Operational Transfer Path Analysis, etc. In this work, the authors analyze a formulation based on the Finite Element Method (FEM) and the computational effort of two methods used to obtain the transmissibility functions for acoustic and vibro-acoustic models. In the first method, the required receptances are extracted from the inverse of the global dynamic stiffness matrix and multiplied to obtain the transmissibility between the involved responses. In the second, the required receptances are extracted from the respective adjugates of the global dynamic stiffness matrix to obtain the transmissibility. A review and comparison of the two methods is presented for acoustic and vibro-acoustic models. To verify and compare both methods, two simple examples are presented. The transmissibility analyses are conducted using a FEM code from where the matrices are extracted and imported to a routine, developed in Matlab environment, used to compute the transmissibility functions estimated by these two methods. The simulation times and accuracy obtained using these methods are presented and briefly discussed. The obtained results confirm the expected significant computational time reduction without loss of accuracy.