###### Abstract  
Due to the limitation of the SEA method, the hybrid FE-SEA method has become a powerful tool to solve the medium-frequency \"acoustic-vibration problem\". However, in most cases, the solution process of the hybrid FE-SEA model is often accompanied by ill-posed matrix problems, such as the inverse solution of the matrix, and the calculation accuracy is not high, which affects the overall calculation accuracy of the hybrid FE-SEA model. In this paper, the calculation method for the effective coupling matrix of the hybrid FE-SEA model is further improved. Based on the basic parameter solving method of the hybrid FE-SEA model, the hybrid FE-SEA model for three-coupled systems is established. In this paper, the deterministic subsystem and the random subsystem response solving problem in three-coupled systems is studied. The method is extended to the multi-coupled system, and an improved calculation method for the coupling matrix of the hybrid FE-SEA model is proposed. On the basis of the weighted iterative method of the principal element, intermediate variables and error transfer are introduced. The parameter identification problem of the effective coupling loss factor of the hybrid FE-SEA model is solved, which provides a solution for parameter identification of the hybrid FE-SEA model. FE-SEA modeling; parameter identification; medium frequency Article An Identification Method for the \"Effective Coupling Loss Factor\" Based on the Hybrid FE-SEA Model  
202313368720233/12/3/1  
accuracy of identification parameters is not high. Moreover, with rapid increase in the number of subsystems, the computational accuracy decreases. With the development of the medium- and low-frequency acoustic-vibration coupling problem and the development of the classical SEA extension method, an accurate and feasible method for parameter identification of the hybrid model is needed. Modeling parameter identification of the hybrid FE-SEA model is related to the solution accuracy of the whole model and is the key to establishing and solving the hybrid model correctly. The identified parameters mainly include the coupling loss factor, the internal loss factor, the output power, the modal density, etc. The basic process of parameter identification is shown in Figure 1. The principle is to compare the differences between the physical model and the computational model and to realize parameter identification by comparing the decoupling model and the power-flow model. At present, there are many studies in the literature on parameter identification of the classical SEA model but few studies on parameter identification of the hybrid model. The research mainly includes the following aspects. [PERSON] [1] has improved the hybrid FE-SEA modeling technology. The complex dynamic system is divided into two parts to solve the problem, and the relationship between the direct field and the reverberation field is deduced. The reciprocity principle of \"direct field\" and \"reverberation field\" is applied to extend the boundary connection to any degree of freedom. At the same time, the parameter identification of the coupling loss factor of the complex system is systematically expounded. [PERSON] [2] studied the modeling parameter identification method of the mixed FE-SEA model. The coupling loss factor, the internal loss factor, and modal density parameter identification methods are included. It is proposed that the above parameters can be solved by the FEA model, and the effectiveness of this method is verified by experiments. This method can consider the detailed structures of complex subsystems, which is helpful to improve the prediction accuracy of the hybrid FE-SEA model in the low- and medium-frequency range. The results show that the coupling loss factor of the mixed model can be obtained by using the FEA finite-element model for low- and medium-frequency analysis.