Exact dynamic characteristic analysis of a double-beam system interconnected by a viscoelastic layer

As an important composite beam structure, the double-beam system with a viscoelastic connection layer has a wide range of applications in engineering. Accurate analysis of its dynamic characteristics is an imperative requirement for the design, monitoring and evaluation, or vibration control of these structures. Existing researches usually introduce some simplifications or assumptions, and ignore the damping characteristics of the structure in most cases, which results in inaccurate dynamic analysis results of such double-beam structures and cannot meet the actual requirements. For this reason, a generalized mechanical model that can consider the damping factor is established in this paper to accurately simulate the double-beam system with a viscoelastic connection layer, and its dynamic characteristics are accurately analyzed by dynamic stiffness method. On this basis, the effects of structural parameters on the modal frequencies and mode shapes of the system are studied. The results show that the stiffness of the connection layer has little effect on the system mode; the modal frequencies of the double-beam system can be reduced by increasing the mass or damping coefficient of the connection layer, where the influence of damping on the low-order modes of the system is very significant, but its effect on the higher-order modes are clearly inferior to that of mass.