Validation of coupled waveguide finite element-wavedomain boundary element (WFBE) method for the case of an infinite plate strip

摘要

The purpose of the work reported here is to validate and verify results obtained using the Waveguide Finite Element and Wavedomain Boundary Element(WFBE) method using the software WANDS. This study concerns the vibro-acoustic behaviour of a plate strip in terms of its mobility, sound radiation and transmission loss. Moreover, it aims to provide a basis for employing the method in more complicated cases. The plate strip is assumed to be infinite in length but have a finite width where it is confined by parallel boundaries. Simply supported boundaries are considered, allowing ready comparison with analytical results. The comparisons between the analytical results and the numerical ones show that WFBE is applicable for investigating the waveguide structure behaviour. However, some practical aspects of implementing this method using the WANDS software should be borne in mind in order to obtain correct results. Firstly, the Waveguide Boundary Element (WBE) mesh must have a closed boundary. Secondly, for comparison with the analytical results, a finite rigid baffle needs to be included in the model by extending the length of the WBE fluid model beyond the width of the structure. Thirdly, in the current implementation of WANDS it is better to use solid elements rather than plates for calculating cases incorporating the WFE-WBE coupling, e.g. the radiated power and the transmission loss. This latter aspect could be dealt with by improvements to the software.