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Communication Dans Un Congrès Année : 2022

The heat build-up and the stress heterogeneity effects on glass-fiber reinforced PA11 under monotonic loading

Lili Wan
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  • IdHAL : lili-wan
Cristian Ovalle
Lucien Laiarinandrasana

Résumé

The heat build-up induced by the conversion of plastic work into dissipative heat [1] is a common phenomenon for polymers subjected to static/dynamic loading. A complex multi-axial stress state leads polymers to ductile deformation and promotes the heat build-up [2], which may result in a significant temperature rise and affects mechanical properties. Without considerations of the heat build-up effect, polymers mechanical responses are not correctly predicted. Thus, it’s of prime importance to understand the heat build-up mechanisms and to develop coupled thermomechanical constitutive models. This study aims at investigating the heat build-up of reinforced PolyAmide 11 (PA11) by taking into account the stress gradient and triaxiality under quasi-static loading. To this end, several uniaxial tensile tests, at three crosshead speeds for PA11 reinforced by three contents of short glass fiber, were carried out on notched and pre-cracked flat samples, i.e. with different theoretical stress state. During the deformation, a high accuracy infrared camera was used to record the specimen’s surface temperature through both thickness and width. Digital image correlation (DIC) technique was employed to obtain the strain field at sample width. The stress state fields, for notched and pre-cracked specimen, are respectively based on Bridgman [3] and HRR [4, 5] theory. For both geometries, good correlations between the profile of heat build-up and theoretical stress states at notch/crack width were highlighted. A heat build-up gradient was observed in sample thickness, which confirms the heterogeneous stress state for the thickness of a flat sample. About evolution of heat build-up with respect to the applied displacement, a significant heat build-up was obtained mainly during the load-softening. Concerning the influence of the fiber contents and crosshead speeds, a higher temperature rise was measured with less glass fiber reinforcement and higher crosshead speed. For the future work, developing and implementing a thermomechanical model, accounting for the heat build-up and the damage, for the simulation of polymer components will be an encouraging challenge. [1] G.I. Taylor and H. Quinney, Proc. R. Soc. Lond. A, 143, 307-326 (1934). [2] C. Ovalle, G. Boisot, and L. Laiarinandrasana, Mechanics of Materials, vol. 145, p.103375 (2020). [3] B. P.W., Twenty-fifth Annual Convention of the Society (Chicago, 1943). [4] J. W. Hutchinson, Journal of the Mechanics and Physics of Solids, vol. 16, no. 1, pp. 13–31 (1968). [5] J. R. Rice and G. F. Rosengren, Journal of the Mechanics and Physics of Solids, vol. 16, no. 1, pp. 1–12 (1968).
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Dates et versions

hal-03994864 , version 1 (17-02-2023)

Identifiants

  • HAL Id : hal-03994864 , version 1

Citer

Lili Wan, Cristian Ovalle, Lucien Laiarinandrasana. The heat build-up and the stress heterogeneity effects on glass-fiber reinforced PA11 under monotonic loading. 15th International Conference on Advanced Computational Engineering and Experimenting (ACEX), Jul 2022, Florence, Italy. ⟨hal-03994864⟩
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