Modeling Aspects of Energy Flow Analysis applied to Timber Structures
* Presenting author
This contribution presents a numerical approach for the prediction of the vibrational energy that flows through structures e.g. made of cross laminated timber.The applicability of the classical FEM is limited since the sensitivity of the results increases with frequency. For higher frequencies, the plates adjacent to a junction can be considered as semi-infinite if the reflections occur with a clearly smaller amplitude or incoherently to the excitation. This enables the use of statistical methods like the Statistical Energy Analysis (SEA). SEA delivers averaged results and thus copes with the sensitivity. The classical SEA is restricted to the wave transmission between plate-like structures. For wood, the elastic modulus perpendicular to the fiber direction is about one thirtieth of the one in fiber direction. Therefore, the thickness modes occur at comparatively low frequencies. Solid elements are able to represent these effects. As both techniques have a restricted validity regarding the frequency range, SEA averaging techniques are applied in the post-processing of the FEM to obtain the Energy Flow Analysis.The necessary resolution in frequency and space as well as comparisons to the SEA suggest dividing the frequency domain into three ranges which offer distinct modeling techniques and evaluation quantities.