| The problem of structures’ dynamical environment prediction has been an issue of great concern in engineering. In recent years, the prediction for structure vibration is not only focus on that in the low-frequency domain, but also in the high-frequency domain. Therefore, higher requirements have been made to the current method of dynamical environment prediction.Finite element method(FEM) plays an important role in the traditional vibration prediction. However, the FEM has an inevitable problem as a deterministic analysis method based on element discrete, which may bring large amount of calculation in the high-frequency domain. In addition, when calculating is proceed in the high-frequency domain, FEM is very sensitive to the variety of the uncertainty parameters, such as structure geometry and physics, which is a factor that limits the application of FEM method in the high-frequency domain.Currently, the method based on energy, such as statistical energy analysis(SEA), is the widely used method for vibration environments prediction, especially for acoustic vibration problems. SEA calculates the average response of the subsystems using the statistics which reduces the influence of the uncertainty of the structure and the great consume of the computer at high frequencies. But SEA can’t get the accurate spatial distribution of the response. Moreover, SEA has strict limit for the modal density of the subsystem which restricts the use of the SEA in engineering. Therefore, a method which overcomes the shortcomings of the certain method and has the advantage of the SEA is ideal. Energy finite element method(EFEA) is just a good choose.In this paper, by studying the EFEA approach, we hope to apply EFEA method to the actual complex engineering problems. Thus, firstly we studied the basic theory EFEA method in this paper. Then we study the EFEA model of the MSC.NASTRAN and develop the model by programing. Besides, we apply the EFEA and SEA to a practical problem for dynamical environment prediction. According to this work, we assess the EFEA for general engineering problems.Because there are few of examples using EFEA for general engineering problems, this paper complete the vibration environment prediction for a complex structure, which is a very significant attempt for EFEA to apply to general engineering problems. |
