###### Abstract
[PERSON] [3] pointed out that the calculation method of the reference solution in parameter identification of the mixed FE-SEA model could be verified by the finite-element random sampling method. The power-flow balance equations of the subsystems are derived by examples, and the responses of each subsystem are obtained using the power-flow balance equations. The results show that the finite-element random sampling method has a good agreement with the prediction results of the existing analysis methods. [PERSON] [4] derived the theoretical calculation formula of the coupling loss factor for arbitrary curve connection and other connection modes according to the calculation theory of coupling loss factors for mixed-model \"line connection\". The theory of parameter identification of the mixed FE-SEA model has been promoted. However, for the theoretical calculation of complex coupling systems, some problems have not been solved yet. [PERSON] [5; 6] used the interval method of Chebyshev polynomials to identify the parameters of a mixed model. The advantage of this identification method is that it does not need to determine the parameter probability distribution. It only needs to determine the parameter interval range and obtain the parameter interval of the system by solving the parameter equation. However, it is only applicable to cases in which the parameter range is small, and the error of solving the parameters in a wide range is large. To solve this problem, [PERSON] [7] proposed an improved parameter perturbation algorithm. The method is applied to parameter identification and system-response prediction of the hybrid model. The improved parameter perturbation method preserves the higher-order term and is used to calculate the inverse of the interval matrix. The Taylor-series-correction algorithm is used to approximate the interval matrix vector, and the differences between the Monte Carlo simulation method and the parameter perturbation method are compared by examples. [PERSON] [8] proposed a finite-element and distribution method to solve the interval parameter linear equation of the system, which separated the non-deterministic parameters. The boundary of each parameter is determined by calculating the extremum problem of the solution of the equation. [PERSON] [9]proposed an unknown-parameter inverse analysis method. The effects of different test precisions and different target parameters on parameter identification results are compared and the convergence conditions of parameter solutions are derived. Methods for the interval parameter identification of mixed models also include the interval Gaussian elimination method, the interval iteration method, the non-probability interval method, the interval correspondence method, the interval perturbation finite-element method, and the Legendre orthogonal polynomial method [10; 11; 12; 13; 14; 15; 16; 17]. In terms of domestic research, [PERSON] [18] applied the FE-SEA hybrid method to analyze the acoustic coupling problem of thin plates under the action of damping materials. Based on the SEA method, the power-flow balance equation of two subsystems is derived. The identification method of the loss-factor parameters in the thin-plate subsystem and its influence on the energy transfer of the hybrid model were studied. The FE-SEA hybrid model was established to verify the validity of parameter identification. In terms of the experimental acquisition of mixed-model parameters, [PERSON] [19] used the PIM power input method to study the coupling loss-factor problem of the experimental acquisition of mixed-model parameters. A new method combining a theoretical method with an experimental method was proposed to determine the energy and equivalent mass of subsystems. Thus, the coupling loss factor of the system was obtained, and the influence of the test error source was avoided. Figure 1: Parameter identification model.