6533b855fe1ef96bd12b0435

RESEARCH PRODUCT

Determination of energy fluxes in composite plates or processed by Vico-constrained damping patch

subject

description

Lightening structures is an important issue in the world of transport. On the other hand, for the improvement of comfort, increasing performance is demanded today, particularly in the vibratory and acoustic field, which leads to the addition of damping materials. The proposed research work consists in the vibrational optimization of the structures by the addition of viscoelastic patches damping positioned wisely. The main function of the viscoelastic used to improve the vibro-acoustic performances, is to provide a mechanism of dissipation of mechanical energy. This attenuation of noise and vibrations causes a conversion of mechanical energy into thermal energy, which, after diffusion into the structure, will disappear by different heat exchange mechanisms. To optimize the positions and shapes of the patches used for the reduction of the vibratory levels, a modeling of the dynamic behavior of the patch structures must be performed. The infrared thermography used to measure the surface thermal fields can then indirectly reveal the zones of mechanical stresses that have appeared in the damping viscoelastic material. These measurements, combined with the thermo-mechanical modeling of the phenomena, will then make it possible to localize the areas to be treated using viscoelastic patches with a minimum weight addition and maximum efficiency. This work includes a theoretical part with the development of models allowing to describe the thermomechanical behavior of the patched structures and an experimental part with the development of a methodology based on the use of the thermal camera for the identification of zones with high deformation energy.Measurements will be carried out on mechanically loaded structures at different frequencies. The state of stress of the set of positioned patches located in the field of view of the thermal camera will be deduced.