Forced response of light weight plates with truss-like cores

Abstract

The waveguide finite element (WFE) method is used for forced response calculations of light weight plates with truss-like cores and produces favourable results for plate investigations where the lateral direction is finite. Standard FE-packages can be used to gain the mass and stiffness matrices of a small slice of the plate. The forced response results presented illustrate the strength of the WFE-calculations. This is demonstrated through comparisons with the outcome of standard FE-calculations. The fact that the plate can be taken as infinite in the longitudinal direction without enlarging the computational effort, is especially valuable for general profile design, since otherwise longitudinal resonances would obscure the trends for arbitrary lengths. It is demonstrated that the application of a reduced wave basis can serve as a promising way to limit the necessary calculation effort for WFE-applications. Only if nearfield effects are of primary concern, the full wave basis has to be retained. The application of standard reduction methods like the Guyan or improved reduction system (IRS) is far less reliable and should be avoided. An example, a regional train floor, demonstrates the applicability of the WFE-method for forced wave propagation on real extruded profile plates. It is demonstrated by mobility measurements that the salient physical behaviour is adequately described by the calculation model.