A New Hybrid Method for Mid-Frequency Vibration of Beam-Plate System Under External Point Loading

Abstract

In this paper, a new hybrid method combining finite element analysis (FEA) and energy finite element analysis (EFEA) is developed for predicting the vibrational response of beam-plate system in mid-frequency range, which enables the local detailed response of the system to be obtained. The waves produced in the system exhibit low- and high-frequency vibrational characteristics simultaneously, which are called stiff member and flexible member separately. The former is modeled using classical FEA, meanwhile the latter is simulated by EFEA. However, unlike classical EFEA, the vibrational energy is considered as the superposition of the direct field and the reverberant field associating the mechanism of wave propagation in high-frequency. Furthermore, the power transfer between two fields is considered according to the transferring pathway analysis of power flow, which is more accurate than the traditional EFEA at the driving points and boundaries. Additionally, the compatibility of the stiff and flexible members is formulated in a global matrix of the system, in which the interactions between these two members are captured. The new developments are validated by a beam-plate system with a line junction under an external point loading applied on the beam, and good correlations are found when compared with the results from very dense classical FEA model.