F. Dinzart

• École Nationale d'Ingénieurs de Metz

Reinforced PPS thermoplastics exposed to variations in temperature and humidity are subject to aging and interface degradation. These phenomena can lead to ruptures due to the interphase weakening. In this study, a micromechanical model based on the equivalent inclusion model is implemented using the viscoelastic behaviours of the neat and aged gra...

In this work, a new micromechanical model is presented to determine the effective behavior of piezoelectric composite materials with ellipsoidal reinforcements and imperfect interfaces. The integral equation is obtained by the Green's function technique applied to the electroelastic heterogeneous problem. This integral equation is further solved in...

A coated inclusion-based homogenization scheme is developed for three-phase viscoelastic composites in the Laplace-Carson domain. The interphase between inclusion and matrix is considered as a coating in a composite-like inclusion and shows altered viscoelastic behavior compared to the matrix. The strain concentration equations between the viscoela...

In this work, a new micromechanical model to determine the effective elastic behavior of composite materials with ellipsoidal reinforcements and imperfect interfaces is developed. By using the Green's functions technique, the integral equation of the linear elastic medium is reformulated in the presence of imperfect interfaces. The integral equatio...

In this work, the effective elastic properties of composite materials with multi-coated reinforcements are estimated by a new formulation of the multi-inclusion model based on Green's functions technique and integral equation which gives the local strain and stress fields through strain concentration equations in each phase of the composite-inclusi...

This contribution is focused on the analysis of the interphase in applied short glass fiber reinforced thermoplastics. The interphase in fiber-matrix composites is defined as the intersection region with modified bulk material properties. Especially for FE simulations of composites and the validation of multi-scale material modeling approaches, the...

The interphase in applied fiber-matrix composites is defined as the intersection region with modified bulk material properties. Especially for FE simulations of composites and the validation of multi-scale material modeling approaches, the information about the existing interphase becomes important. In this study, the interphase thickness in a shor...

The interphase in applied fiber-matrix composites is defined as the intersection region with modified bulk material properties. Especially for FE simulations of composites and the validation of multi-scale material modeling approaches, the information about the existing interphase becomes important. In this study, the interphase thickness in a shor...

A new time-incremental internal variables homogenization scheme for Maxwellian linear viscoelastic heterogeneous materials is proposed. This scheme is based on the exact solution of the ellipsoidal Eshelby inclusion problem obtained in the time domain. In contrast with current existing methods, the effective behavior as well as the evolution laws o...

Abstract This study presents the experimental characterization of new thermoplastic elastomers that comprised polypropylene and waste tire rubber (WTR). The processing was investigated to obtain standard tensile test samples. Particles and matrix compatibilization has been examined and the melt flow index was found to be a suitable way to determin...

In this work, a new homogenization method to estimate the effective behavior of viscoelastic heterogeneous materials with multi-coated reinforcements is presented. Unlike classical methods that are based on the Laplace transform, the present internal variables formulation operates directly in the time domain. Using the Green’s function techniques,...

This paper is devoted to present an approach to model behavior of hemp fibers reinforced thermoplastic composites. Experimental investigations using common testing methods have shown that major physical dissipative phenomena which explained the behavior of polypropylene/ hemp fibers (PP/Hemp) composites took place in the matrix. Moreover these diss...

This paper is devoted to present an approach to model behavior of hemp fibers reinforced thermoplastic composites. Experimental investigations using common testing methods have shown that major physical dissipative phenomena which explained the behavior of polypropylene/ hemp fibers (PP/Hemp) composites took place in the matrix. Moreover these diss...

This article is devoted to the study of mechanical behaviour of a polypropylene reinforced with short hemp fibres available industrially. The main objective of this study is to understand the major physical phenomena to be taken into account to propose, in an upcoming work, a relevant modelling of these composites. Important experimental investigat...

In this study, the magnetoelectroelastic behavior is investigated for magnetic–piezoelectric composites with coated reinforcements under antiplane mechanical and in-plane electromagnetic loads. The coating is considered as a layer with properties different from those of the inclusion and the matrix. The developed model is based on the solution of t...

Résumé : Ces travaux portent sur l'étude du comportement et de l'endommagement d'un thermoplastique, polypropylène, chargé de fibres courtes de chanvre. Des essais de traction à différentes vitesses de déformations (10 -4 à 10 -2 s -1), températures (0°C à 60°C) et taux de chanvres (5% à 20%) ont été effectués. Le comportement thermomécanique dynam...

Résumé : L'insertion dans une matrice thermoplastique (PP) de poudrettes (< 1 mm) de pneumatiques usagés (PUNR) issues de broyage est une voie de valorisation. Après formulation du mélange compatibilisé pour cinq taux massique de PUNR de 5% à 25%, des essais de traction ont été réalisés à trois vitesses de déformation (10 -4 , 10 -3 , 10 -2 s -1)....

In this work, a micromechanical model for the estimate of the magneto-electro-elastic behavior of the magnetic-piezoelectric composites with coated reinforcements is proposed. The coating is considered as a thin layer with properties different from those of the inclusion and the matrix. The micromechanical approach based on the Green’s functions te...

The constitutive law of a two-phase isotropic polymer blending described by fractional derivative models is obtained through a classical self-consistent scheme. A parametric analysis is driven to describe the influence of the four parameters associated with the constitutive law description and to comprise the conditions of application of the model....

In this work, a micromechanical model for the estimate of the electroelastic behavior of the piezoelectric composites with coated reinforcements is proposed. The piezoelectric coating is considered as a thin layer with active electroelastic properties different from those of the inclusion and the matrix. The micromechanical approach based on the Gr...

The dynamic behaviour of elastomers is assumed to follow a constitutive dif-ferential equation of non-integral (fractional) order. In order to describe the peculiar frequency response of the loss factor, the constitutive equation has been refined by introducing the fifth parameter to the classical fourth-order equation. The asymmetry of the loss fa...

The thermomechanical response of beams made up of thermoplastic polymer is analysed in the case of cyclic bending. The material behavior is modelled by a viscoelastic law depending on temperature and frequency. Inertia eects are neglected. The stress, strain and temperature distributions are expressed as functions of the beam geometry, the loading...

The temperature distribution is determined in a tube, made up of a polymeric material, sustaining a cyclic torsion. The existence and stability of stationary solutions are assessed. The temperature may reach a steady-state value depending on the balance in the heat generated by deformation and the heat removal at the surroundings. The influence of...

The shear band structure in a thermo-viscoplastic material has been analyzed under quasi-static conditions during the final stage of the localization process. A closed form expression of the bandwidth, of the size of the heat-affected zone and of the failure time has been obtained for a homogeneous material. The analysis is based on the assumption...

Le couplage thermo-mécanique et l'adoucissement thermique sont les propriétés du matériau qui sont à l'origine du développement des bandes de cisaillement adiabatique. Cependant les défauts géométriques ou métallurgiques fournissent les sites où le processus de localisation de la déformation plastique est initié. Dans cet article, les effets de la...