Development of a Novel Deterministic-Statistical Approach for Vibro-Acoustic Problems in Mid-Frequency based on Modified Integration Rule

Abstract

Recently, FE-SEA was proposed especially for the analysis of vibro-acoustic problems in mid-frequency regime. In practical applications, the use of conventional FEM in this hybrid FE-SEA method entails some inherent drawbacks, which is closely associated with well-known “overly-stiff” feature of FEM and the balance of mass matrix and stiffness matrix. In this work, a modified integration rule (MIR) is applied in the acoustic FEM model to readjust the mass matrix. Then, the MIR-FEM is embedded to achieve a hybrid MIR-FE-SEA framework, aiming to further improve the accuracy of mid-frequency response prediction. In the proposed MIR-FE-SEA model, the plate structure which often has a higher modal density is considered as a statistical subsystem and modeled statistically using statistical energy analysis (SEA). The acoustical cavity with a relative lower modal density is modeled deterministically using MIR-FEM. The coupling between these two different types of subsystems is achieved through the diffuse field reciprocity relation. The proposed MIR-FE-SEA is verified by various numerical examples.