Elastic-viscoelastic-elastic composite (EVEC) structure is an efficient vibration suppression technology which can be applied to a variety of environments. The method to determine the parameters of the Biot constitutive model of the viscoelastic material, to incorporate the model into EVEC finite element dynamic equations and to reduce the dimension of the equations, is investigated. The conventional nonlinear curve fitting problem is transformed into the nonlinear optimization problem with constraints in complex frequency domain. The Biot model is integrated into the finite element dynamic equations of the EVEC structures by introducing the auxiliary coordinate after a series of mathematical transformations, and then the modal parameters can be solved directly. The traditional iterative can be avoided, and the calculation process is greatly simplified. The finite element shear, compressional and combination models of the EVEC beam structure are established based on different energy consumption patterns. The convergence of the corresponding finite elements is investigated. The linear and nonlinear vibration characteristics of the EVEC beam structure are studied for different boundary conditions and structural parameters. Numerical simulation results show the scope of application of the three finite element models, and the damping mechanism of the EVEC beam structure are revealed as well. The EVEC beam / plate structures are studied experimentally. The storage modulus and loss factor of the ZN-1 type viscoelastic material are measured for nonlinear curve fitting to determine the parameters of the Biot model. Thirty EVEC beams with different thicknesses are tested to obtain the natural frequencies and loss factors. The experimental results provide validation for the finite element shear, compressional and combination models of the EVEC beam structures. The scopes of application of the three models are determined from the quantization.

Professor Fulei Chu received his PhD from Southampton University in UK. He is now a professor of mechanical engineering at Tsinghua University in Beijing. He is the Vice President of the Chinese Society for Vibration Engineering (CSVE). He serves as members of the editorial board for many journals, including Proceedings of the Institution of Mechanical Engineers-Part C, Journal of Mechanical Engineering Science, Journal of Vibration Engineering, Journal of Vibration and Shock, Mechanical Engineering and Technology and others. His research interests include rotating machinery dynamics, machine condition monitoring and fault detection, nonlinear vibration and vibration control. He has published more than 300 papers in peer review journals, including more than 30 papers in the Journal of Sound and Vibration and 25 papers in the journal of Mechanical Systems and Signal Processing. He has received many awards in China, including the Outstanding Young Researcher Award from Natural Science Foundation of China.