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For the case of the in-plane vibration of a plate, the power is carried by shear and longitudinal waves generating an in-plane two-dimensional displacement field. The objective of this paper is to propose experimental techniques for the measurement of the in-plane vibration intensity (power flow per unit width of a cross section) of the plate. The theoretical basis is outlined for the experimental techniques. The experimental techniques have been implemented to measure the in-plane vibration intensity in the plate. The experimental results of the in-plane vibration intensity in the plate have been compared with the theoretical results. It is shown that the experimental techniques can be effectively used to measure the in-plane vibration intensity in the plate.

In this paper, Power Flow Boundary Element Method (PFBEM) is studied as a new tool of the noise and vibration analysis in medium-to-high frequency ranges, and the noise and vibration prediction software using this method is developed. The developed prediction system includes both direct and indirect approaches, and also offers the various functions like baffled condition, absorption boundary condition and so forth. To verify the accuracy, the developed prediction system is applied to the prediction of the vibration energy distributions in simple beams and thin plates, and the results are compared with the exact solutions of Power Flow Analysis (PFA). As practical examples, car cabins surrounded by the materials of different absorption coefficients are modeled and the distributions of smoothed acoustical energy density are successfully predicted.

The Power Flow Finite Element Method (PFFEM) offers very promising results in predicting the vibration responses of system structures. We have developed the PFFEM based software for the vibration analysis in medium-to-high frequency ranges. The software can analyze the system structures composed of beam, plate, shell, link and other. components developed, and has many useful functions. In homogeneous domain, the software solves the energy governing differential equations for multi-DOF structural elements. At the discontinuities, it generates joint elements to cover the vibrational attenuation and can solve the joint element equations by using the wave transmission approach very efficiently. For the application of real vehicle system, an automobile is examined with respect to several parameters.

The Energy Flow Analysis (EFA) offers very promising results in predicting the noise and vibration responses of system structures in medium-to-high frequency ranges. We have developed the Energy Flow Finite Element Method (EFFEM) based software, EFADS C++ R4, for the vibration analysis. The software can analyze the built-up structures composed of beam, plate, spring-damper, rigid body elements and so on, and has many useful functions. For the effectiveness and convenience of software, the main functions of the whole software are modularized into translator, model-converter, and solver. The translator module makes it possible to use of finite element (FE) model for the vibration analysis at low frequencies. The model-converter module changes FE model into energy flow finite element (EFFE) model.

The Energy Flow Analysis (EFA) can be effectively used to predict structural vibration in medium-to-high frequency range. In this paper, Energy Flow Finite Element Method (EFFEM) based on EFA has been used to predict the vibration of an automobile door. The predicted results for the frequency response function of the door have been compared with corresponding experimental results. In the experiment, the automobile door has been divided into several subsystems and the loss factor of each subsystem has been measured. The input mobility at a source point has been also measured. The data for the loss factors and the input mobility have been used as the input data to predict the vibration of the automobile door with EFFEM. The frequency response functions have been measured over the surface of the door.