The modelisation of constrained damping layer treatments using the finite element method: spatial model and viscoelastic behaviour

Abstract

Surface and integrated damping treatments with viscoelastic layers play an important position among the passive damping treatments for light and flexible structures under vibration. Application simplicity, low cost, reduced structural modification and reduced additional mass, along with an inherent high efficiency, are the main reasons of it successful usage. However, the design process of these treatments is not simple and requires a reliable tool for adequate designing and analysis. The finite element method can be used for this purpose. However some considerations and special care are necessary to the spatial modelisation of the treatment and with the viscoelastic material properties characterisation. In this work, a finite element commercial software (MSC/Nastran) was used to simulate the constrained and the integrated viscoelastic treatments applied on aluminium plates. The spatial modeling of the treatment is developed using a layered scheme of plate/brick conventional finite elements. The dynamic properties of the viscoelastic material are taken into account in the numerical simulation using the complex modulus approach. The numerical results are correlated with experimental data obtained in four treated specimens by direct comparison of the frequency response functions and by using some FRF-based correlation indicators.