Finite Element Analysis Of The Vibration Characteristics Of Sandwich Structure With Viscoelastic Layer

Currently, elastic-viscoelastic complex structures are widely utilized in reducing the structural vibrations. How to analyze the vibration of the viscoelastic damped structure accurately and optimize it has been an important question in designing damped structures. Because the conventional method depends on many experiments and experiences, it costs too much in application. Considering this problem, The author makes the numerical computation of the sandwich structure through FEA. Based on this, the optimization of the structure through NN is also presented in this paper.Because of the frequency-dependent property of viscoelastic material, the structure is difficult to be analyzed by usual method. To solve this problem, the author proposes the modal strain energy iteration method, and using ANSYS to calculate the resonance frequencies and loss factors of the damped sandwich structure. Some factors such as the restriction, thickness and temperature which affect the vibration characteristics of the structure are also discussed. This method is available in analyzing and designing viscoelastic damped structure, and it can give an assurance of practicability and accuracy. Hence, it has great value in both theory and application of the damping engineering.Based on the results of the finite element analysis, the GRNN which replaces the conventional method, is used to establish the parametric fitting expressions of the resonance frequeneies and loss factors with geometric parameters of the strueture. Then, the author uses the SQP arithmetic to optimize the geometric parameters. The result testifies it works well. This method could get accurate model through less FEA, and make the optimization more effective.In this paper, the dynamic response of the damped structure is also studied. By using a simplified numerical method which is given for the approximate computation in engineering, the author computes the dynamic response of the complex sandwich structure under harmonic excitation through ANSYS. The damping ratio of the structure is regarded as Rayleigh damping ratio in this method. At the end, an experiment scheme is given for further research.