Determination of thermal contact conductance in vacuum-bagged thermoplastic prepreg stacks using infrared thermography

Baumard, Théo; Almeida, Olivier de; Menary, Gary; Maoult, Yannick Le; Schmidt, Fabrice; Bikard, Jérôme

doi:10.1063/1.4963511

Cited by 3 publications

(3 citation statements)

References 13 publications

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“…Additional problematics have to be considered to propose a comprehensive simulation approach for the direct forming of non-consolidated semipreg, as both the infrared heating phase and the impregnation/reconsolidation will involve different mechanisms. The matrix droplets at the surface of the fabric lead to thermal contact resistances that increase temperature gradients through-the-thickness in multiply stacks [58]; the thick resin-rich interlayer might affect interply slip behaviour which in turns impacts the magnitude of wrinkles [59,60]. The effect of intra-ply sliding on the quality of impregnation of the final part will also have to be investigated [61,62].…”

Section: Discussionmentioning

confidence: 99%

Experimental characterization and modeling of the temperature and rate-dependent shear behaviour of powder-impregnated glass fiber/PA66 woven semipregs

Baumard

Menary

Almeida

et al. 2019

Composites Science and Technology

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This study focuses on the characterization of the in-plane shear response of a novel powder-impregnated, nonconsolidated PA66/glass semipreg to evaluate its forming behaviour. The effects of temperature and rate on the behaviour of the semipreg and the preconsolidated material were investigated using bias-extension tests. Results obtained show an increase in shear stress with decreasing temperature and increasing rate, with the semipreg exhibiting a lower sensitivity to the test speed. An increase of the flow distance to impregnate the yarns, due to intra-ply sliding mechanisms specific to the powder-impregnated semipreg, is observed. A model based on a hypoelastic approach with temperature and rate dependence is proposed to represent the material behaviour. Isothermal simulations of the bias-extension test are conducted. Results show a good agreement between the model and experimental data in terms of force and shear angle prediction.

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Section: Discussionmentioning

confidence: 99%

Experimental characterization and modeling of the temperature and rate-dependent shear behaviour of powder-impregnated glass fiber/PA66 woven semipregs

Baumard

Menary

Almeida

et al. 2019

Composites Science and Technology

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“…Thermal contact resistance consists in quantifying the heat transfer between two domains (for example, the part and the mold) by intrinsically taking into account surface defects, possible air gaps or contact losses. [56][57][58] FreeFem++ makes it possible to properly consider this parameter by simultaneously solving the transient heat transfer both in the mold and in the part, thus introducing a strong coupling between domains. TCRs are usually supposed to be constant, both temporally and spatially, since the heat transfer in thin plates is mainly driven by convection and by conduction in the composite.…”

Section: Main Modelling Strategiesmentioning

confidence: 99%

Thick thermoplastic composite laminate consolidation: Experimental observations and numerical approaches

Denis

NGuyen

Lecointe

et al. 2022

Journal of Composite Materials

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Since the benefits of composite materials have been demonstrated, particularly those relevant to the fields of transports and energy, increasingly high industrial expectations are emerging. As the control of the processes is complex, the thickness of the composite materials does not usually exceed a few millimetres. The aim of the work presented in this paper is to highlight new phenomena related to the oven/autoclave consolidation of thicker thermoplastic composites. In the case of such thick composites, the influence of certain phenomena that are usually neglected becomes important and a physical interpretation becomes necessary (the thermal contact resistance between mold and part and the influence of mold geometry). Here, an experimental approach is compared with numerical simulations of heat transfer and crystallization in order to validate the proposed thermokinetics model. Finally, some numerical observations are discussed and analyzed.

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“…This study was conducted at Institut Clément Ader, using a novel method based on infrared thermography and inverse analysis to identify the temperatures of the lamps and thermal conductivity tensor of the material [9]. This experimental setup also allowed to characterize the inter-ply thermal contact resistances in a non-consolidated composite stack.…”

Section: Heating Simulationmentioning

confidence: 99%

Towards a coupled heating-forming simulation of the thermoforming of thermoplastic composites

Baumard

Menary

Almeida

et al. 2017

AIP Conference Proceedings

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Abstract.A strategy for the simulation of the whole thermoforming process, from the infrared heating to the stamping, is presented here. Two loosely coupled simulation tools are being developed: the first one computes a realistic 3D, transient temperature field of the composite stack inside an infrared oven, considering the radiative, conductive and convective heat transfers; the temperature distribution is used as an input for the second that aims at simulating the thermomechanical behaviour of the composite during the forming step via a non-orthogonal constitutive model. The steps for the identification of the model parameters are introduced. Initial validation tests show realistic results in term of shear angle distribution.

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Determination of thermal contact conductance in vacuum-bagged thermoplastic prepreg stacks using infrared thermography

Cited by 3 publications

References 13 publications

Experimental characterization and modeling of the temperature and rate-dependent shear behaviour of powder-impregnated glass fiber/PA66 woven semipregs

Experimental characterization and modeling of the temperature and rate-dependent shear behaviour of powder-impregnated glass fiber/PA66 woven semipregs

Thick thermoplastic composite laminate consolidation: Experimental observations and numerical approaches

Towards a coupled heating-forming simulation of the thermoforming of thermoplastic composites

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