The objective of this research is model numerically a washing machine in order to forecast and optimize the acoustic emission. The work can be divided in two main parts (dynamic modeling and acoustic modeling) and
only one software is used for work: LMS Virtual.Lab. The first part involves the realization of the parametric model 3D CAD of the washing
machine and its dynamic simulation in the multi-body environment of LMS Virtual.Lab Motion. The multi-body technique allows the interaction among various parts that compose the appliance,
the known inputs and the gravity. The external forces applied to the numerical model come from experimental accelerations acquired directly on the physical model in various conditions. Accelerations are converted in forces by processing. Thus the experimental outputs become,
based on the inverse analysis method, the numerical inputs.
Then the model is implemented by introducing of flexible parts in order to make it closer to the physical one. In this particular case, two washing machine parts are meshed (the tub and the case) with the finite element method (FEM). The structural mesh is uses first of all for the modal
analysis of the single parts and then for the vibrational rigid-flexible analysis of the whole model when even the external forces are considered. The dynamic rigid-flexible simulations are then
compared and validated with experimental tests. The second part has as purpose the studying of the acoustic behavior of the washing
machine to forecast acoustic emission. So an acoustic model is created in the LMS Virtual.Lab Acoustics environment that permits to analyze the panel acoustic power sound emission based on the dynamic rigid-flexible simulation results previously performed in the LMS Virtual.Lab
Motion multibody environment. In this specific case, the acoustic inputs are the dynamic simulations outputs: surfacing speeds depending on the modal participation factors calculated considering the natural frequencies of the panels. The acoustic analysis is carried out by the
boundary element technique (BEM) that allows the construction of the acoustic mesh of the washing machine case based on the structural mesh. The panel acoustic power is then compared and validated with experimental tests where the acoustic holography technique is used.
In the present work a numerical model of the washing machine vibro-acoustic behavior is shown. The future work will be the optimizing the acoustic emission depending on the geometry, materials and the domestic environment conditions is reached.
