scholarly journals Fiber Orientation Predictions—A Review of Existing Models

2020 ◽  
Vol 4 (2) ◽  
pp. 69 ◽  
Author(s):  
Susanne Katrin Kugler ◽  
Armin Kech ◽  
Camilo Cruz ◽  
Tim Osswald
Keyword(s):  
Fiber Orientation ◽  
Mechanical Performance ◽  
Historical Review ◽  
Fiber Reinforced Polymers ◽  
Strong Impact ◽  
Fiber Reinforced ◽  
Reinforced Polymers ◽  
Virtual Engineering ◽  
Rotary Diffusion ◽  
Orientation Phenomenon

Fiber reinforced polymers are key materials across different industries. The manufacturing processes of those materials have typically strong impact on their final microstructure, which at the same time controls the mechanical performance of the part. A reliable virtual engineering design of fiber-reinforced polymers requires therefore considering the simulation of the process-induced microstructure. One relevant microstructure descriptor in fiber-reinforced polymers is the fiber orientation. This work focuses on the modeling of the fiber orientation phenomenon and presents a historical review of the different modelling approaches. In this context, the article describes different macroscopic fiber orientation models such as the Folgar-Tucker, nematic, reduced strain closure (RSC), retarding principal rate (RPR), anisotropic rotary diffusion (ARD), principal anisotropic rotary diffusion (pARD), and Moldflow rotary diffusion (MRD) model. We discuss briefly about closure approximations, which are a common mathematical element of those macroscopic fiber orientation models. In the last section, we introduce some micro-scale numerical methods for simulating the fiber orientation phenomenon, such as the discrete element method (DEM), the smoothed particle hydrodynamics (SPH) method and the moving particle semi-implicit (MPS) method.

scholarly journals A Flow-Dependent Fiber Orientation Model

2020 ◽  
Vol 4 (3) ◽  
pp. 96
Author(s):  
Susanne Katrin Kugler ◽  
Argha Protim Dey ◽  
Sandra Saad ◽  
Camilo Cruz ◽  
Armin Kech ◽  
...  
Keyword(s):  
Fiber Orientation ◽  
Mechanical Performance ◽  
Mechanistic Model ◽  
Elongational Flow ◽  
Simulation Software ◽  
Fiber Reinforced Polymers ◽  
Macroscopic Model ◽  
Fluid Viscosity ◽  
Fiber Reinforced ◽  
Elongational Flows

The mechanical performance of fiber reinforced polymers is dependent on the process-induced fiber orientation. In this work, we focus on the prediction of the fiber orientation in an injection-molded short fiber reinforced thermoplastic part using an original multi-scale modeling approach. A particle-based model developed for shear flows is extended to elongational flows. This mechanistic model for elongational flows is validated using an experiment, which was conducted for a long fiber reinforced polymer. The influence of several fiber descriptors and fluid viscosity on fiber orientation under elongational flow is studied at the micro-scale. Based on this sensitivity analysis, a common parameter set for a continuum-based fiber orientation macroscopic model is defined under elongational flow. We then develop a novel flow-dependent macroscopic fiber orientation, which takes into consideration the effect of both elongational and shear flow on the fiber orientation evolution during the filling of a mold cavity. The model is objective and shows better performance in comparison to state-of-the-art fiber orientation models when compared to μCT-based fiber orientation measurements for several industrial parts. The model is implemented using the simulation software Autodesk Moldflow Insight Scandium® 2019.

scholarly journals Model Calibration and Data Set Determination Considering the Local Micro-Structure for Short Fiber Reinforced Polymers

2021 ◽  
Vol 5 (2) ◽  
pp. 40
Author(s):  
Andreas Primetzhofer ◽  
Gabriel Stadler ◽  
Gerald Pinter ◽  
Florian Grün
Keyword(s):  
Fiber Orientation ◽  
Model Calibration ◽  
Short Fiber ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Micro Structure ◽  
Data Set ◽  
Reinforced Polymers ◽  
Whole Life Cycle ◽  
Local Fiber

To ensure the usability of parts made of fiber-reinforced polymers, a lifetime assessment has to be made in an early stage of the development process. To describe the whole life cycle of these parts, continuous simulation chains can be used. From production to the end of the service life, all influences are mapped virtually. The later material strength is already given after the manufacturing process due to the process dependent fiber alignment. To be able to describe this fiber orientation within the lifetime assessment, this paper presents an approach for model calibration and data set determination to consider the local micro-structure. Therefore, quasi-static and cyclic tests were performed on specimens with longitudinal and transversal fiber orientation. A supplementary failure analysis provides additional information about the local micro-structure. The local fiber orientation is determined with µCT (micro computer tomography)-measurements, correlated to the extraction positions of the specimen, and implemented in a dataset. With an attached lifetime calculation on a demonstrator, a major influence of the local micro-structure on the calculation results can be shown. Therefore, it is indispensable to consider the local fiber orientation in the data set determination of short fiber reinforced polymers.

Macroscopic fiber orientation model evaluation for concentrated short fiber reinforced polymers in comparison to experimental data

2020 ◽  
Vol 41 (7) ◽  
pp. 2542-2556 ◽  
Author(s):  
Susanne K. Kugler ◽  
Gregory M. Lambert ◽  
Camilo Cruz ◽  
Armin Kech ◽  
Tim A. Osswald ◽  
...  
Keyword(s):  
Experimental Data ◽  
Model Evaluation ◽  
Fiber Orientation ◽  
Short Fiber ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Reinforced Polymers ◽  
Orientation Model

scholarly journals Assessing the performance of electrospun nanofabrics as potential interlayer reinforcement materials for fiber-reinforced polymers

2021 ◽  
Vol 30 ◽  
pp. 263498332110025
Author(s):  
Katerina Loizou ◽  
Angelos Evangelou ◽  
Orestes Marangos ◽  
Loukas Koutsokeras ◽  
Iouliana Chrysafi ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Mechanical Response ◽  
Mechanical Performance ◽  
Polyamide 6 ◽  
Processing Parameters ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Scanning Calorimetry ◽  
Multiwalled Carbon ◽  
Reinforced Polymers

Multiscale-reinforced polymers offer enhanced functionality due to the three different scales that are incorporated; microfiber, nanofiber, and nanoparticle. This work aims to investigate the applicability of different polymer-based nanofabrics, fabricated via electrospinning as reinforcement interlayers for multilayer-fiber-reinforced polymer composites. Three different polymers are examined; polyamide 6, polyacrylonitrile, and polyvinylidene fluoride, both plain and doped with multiwalled carbon nanotubes (MWCNTs). The effect of nanotube concentration on the properties of the resulting nanofabrics is also examined. Nine different nanofabric systems are prepared. The stress–strain behavior of the different nanofabric systems, which are eventually used as reinforcement interlayers, is investigated to assess the enhancement of the mechanical properties and to evaluate their potential as interlayer reinforcements. Scanning electron microscopy is employed to visualize the morphology and microstructure of the electrospun nanofabrics. The thermal behavior of the nanofabrics is investigated via differential scanning calorimetry to elucidate the glass and melting point of the nanofabrics, which can be used to identify optimum processing parameters at composite level. Introduction of MWCNTs appears to augment the mechanical response of the polymer nanofabrics. Examination of the mechanical performance of these interlayer reinforcements after heat treatment above the glass transition temperature reveals that morphological and microstructural changes can promote further enhancement of the mechanical response.

scholarly journals Phase-contrast and dark-field imaging for the inspection of resin-rich areas and fiber orientation in non-crimp vacuum infusion carbon-fiber-reinforced polymers

2021 ◽  
Vol 56 (16) ◽  
pp. 9712-9727 ◽  
Author(s):  
Jonathan Glinz ◽  
Jan Šleichrt ◽  
Daniel Kytýř ◽  
Santhosh Ayalur-Karunakaran ◽  
Simon Zabler ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Fiber Orientation ◽  
Phase Contrast ◽  
Dark Field ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced Polymers ◽  
Reinforced Polymers ◽  
Vacuum Infusion ◽  
Carbon Fiber Reinforced

AbstractIn this work, we present a multimodal approach to three-dimensionally quantify and visualize fiber orientation and resin-rich areas in carbon-fiber-reinforced polymers manufactured by vacuum infusion. Three complementary image modalities were acquired by Talbot–Lau grating interferometer (TLGI) X-ray microcomputed tomography (XCT). Compared to absorption contrast (AC), TLGI-XCT provides enhanced contrast between polymer matrix and carbon fibers at lower spatial resolutions in the form of differential phase contrast (DPC) and dark-field contrast (DFC). Consequently, relatively thin layers of resin, effectively indiscernible from image noise in AC data, are distinguishable. In addition to the assessment of fiber orientation, the combination of DPC and DFC facilitates the quantification of resin-rich areas, e.g., in gaps between fiber layers or at binder yarn collimation sites. We found that resin-rich areas between fiber layers are predominantly developed in regions characterized by a pronounced curvature. In contrast, in-layer resin-rich areas are mainly caused by the collimation of fibers by binder yarn. Furthermore, void volume around two adjacent 90°-oriented fiber layers is increased by roughly 20% compared to a random distribution over the whole specimen.

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