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Homogénéisation multi-échelle pour un objectif d’amortissement modal dans la conception d’aubes composite tissé 3D

Abstract : The goal of this work is to control the damping of the first modes of the fan blade during the design phase.A numerical method for the viscoelastic homogenization of 3D woven composite materials is developed. Two homogenizations are made, at the yarn's scale and at the woven one. The complex modulus of the resin, the elastic properties of the yarns and the geometry of the microstructure allow a characterization of the damping in frequency and temperature. The matrix formulation of the homogenization, for a finite element implementation, allowed the use of model reduction techniques in parametric studies on the viscoelastic properties of the composite's constituents.A comparison of the numerical predictions with the modal damping obtained by modified Oberst test, for low frequencies and a range of temperature between -40°C and 120°C, provided coherent results in terms of absolute values and trends. These tests also show areas of stress gradient which are small compared to the weaving pattern size motivating the introduction of a verification methodology of the scale separation hypothesis at different wavelengths. The definition of the elastic and dissipated energy fractions by decomposition of the constitutive law into singular values allows an analysis of the main contributions to the damping at both 3D woven and fan blade scale.The insertion of a hybridized 3D woven composite with elastomer tows within the fan blade is proposed in order to increase the modal damping of the first flexion. A spatial study of the areas dissipating the most energy is performed to optimize the placement of the hybrid weaving pattern.
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Submitted on : Tuesday, May 24, 2022 - 3:29:12 PM
Last modification on : Saturday, August 6, 2022 - 3:07:42 AM

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  • HAL Id : tel-03677256, version 1

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Florian Conejos. Homogénéisation multi-échelle pour un objectif d’amortissement modal dans la conception d’aubes composite tissé 3D. Mécanique des matériaux [physics.class-ph]. HESAM Université, 2021. Français. ⟨NNT : 2021HESAE022⟩. ⟨tel-03677256⟩

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