Complex fibers orientation distribution evaluation in short glass fiber-reinforced thermoplastic (PA66 GF50)

Abstract

Abstract. The use of composites made of polyamide 6.6 matrix and short-glass-fibers in automobile industry is progressive due to its low density and cost. The injection molded short glass fiber-reinforced (SGFR) thermoplastics structural parts such as intake, manifold and engine mount housing, induce complex fiber orientation distributions (FOD). This microstructure governs the macroscopic properties such as the mechanical stiffness and fatigue resistance. To estimate the FOD on such industrial parts at complex angles and ribs, we rely on simulation results and micro tomography analysis. The interest of this paper is to develop a semi-automated, quick and efficient orientation tensor identification approach from 2D microscopic images, which is capable of observing relatively larger surface compared to micro tomography. We finally conclude by comparing it with micro tomography and simulation results. Furthermore, we investigate its relevance with fatigue service ability.

A model to describe the cyclic anisotropic mechanical behavior of short fiber-reinforced thermoplastics

“…As proposed in [4] for example, the microstructure is characterized by the distribution of fibers orientations, described by a second-order tensor a ψ and a fourth-order tensor A ψ . a ψ was determined from 2D optical micrographs by following the procedure described in [5]. A ψ is estimated from a ψ using the orthotropic fitted closure equation proposed by Cintra and Tucker [6].…”

“…D is an operator applied to second-order tensors defined by D ijkl (a, b) = a ik b jl + a il b jk + a jl b ik + a jk b il . The constants K i with i ∈ [1,5] are given in [16].…”

Structure Analysis and Its Correlation with Mechanical Properties of Microcellular Polyamide Composites Reinforced with Glass Fibers

“…Sample preparation either for SEM or optical microscopy is not straightforward with thick-walled (thicker than 4 mm) samples of polyamides reinforced with glass fiber [10]. Because of cell deformation, the invasive sample preparation process can be even more difficult for foamed pieces.…”