Comparison between finite element and hybrid finite element results to test data for the vibration of a production car body

Abstract

The Hybrid Finite Element Analysis (Hybrid FEA) method is based on combining conventional Finite Element Analysis (FEA) with analytical solutions and energy methods for mid-frequency computations. The method is appropriate for computing the vibration of structures which comprises stiff load bearing components and flexible panels attached to them and for considering structure-borne loadings with the excitations applied on the load bearing members. In such situations, the difficulty in using conventional FEA at higher frequencies originates from requiring a very large number of elements in order to capture the flexible wavelength of the panel members which are present in a structure. In this presentation a three-way comparison will be offered for the vibration of a production vehicle body in the frequency range 200 Hz–1000 Hz. Six different excitation locations are utilized (one at a time); for each excitation the mobility of five reference body points on the load bearing members, and the mobility of eight flexible vehicle panels is measured and the measurements are compared with both conventional FEA results and with Hybrid FEA computations. Discussion about the development of the Hybrid FEA model and the correlation of both numerical solutions to the test data will be presented.The Hybrid Finite Element Analysis (Hybrid FEA) method is based on combining conventional Finite Element Analysis (FEA) with analytical solutions and energy methods for mid-frequency computations. The method is appropriate for computing the vibration of structures which comprises stiff load bearing components and flexible panels attached to them and for considering structure-borne loadings with the excitations applied on the load bearing members. In such situations, the difficulty in using conventional FEA at higher frequencies originates from requiring a very large number of elements in order to capture the flexible wavelength of the panel members which are present in a structure. In this presentation a three-way comparison will be offered for the vibration of a production vehicle body in the frequency range 200 Hz–1000 Hz. Six different excitation locations are utilized (one at a time); for each excitation the mobility of five reference body points on the load bearing members, and the mobility of eight ...