Download or read book Observation of Fiber Orientation in Injection Molded Long Fiber Reinforced Composites written by 楊怡福 and published by . This book was released on 2018 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Natural Fiber Orientation in Polymer Composites Produced by Injection Molding Process written by Rajasekaran Karthikeyan and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Short fiber reinforced polymer composites (SFRPC) produced by injection molding process have established a commercial utilization in all sectors due to low cost and lower weight of the components. The polymers are reinforced with natural fibers to improve their performance. The orientation of short natural fibers in the polymer composite influences the mechanical performance. This research thus focused on the prediction of natural fiber orientation using a theoretical model and then studied the mechanical properties of natural fiber reinforced composites. The theoretical model was derived by incorporating the shape factor of natural fibers into the angular velocity of the fluid element in order to predict the orientation during the injection molding process. The ANSYS- FLUENT software was used to find the velocity distribution in the fluid domain, from which the angular velocity of the fluid element and the orientation angle were found numerically. This numerical orientation result was then compared to the experimental data. The orientation angle of rigid particles rotating at a fixed distance from the inlet gate was measured by an experimental method where a transparent cavity was filled through an injection molding process An experimental setup was developed to study the orientation behavior of short natural fibers in the flowing viscous fluid. Two experimental case studies were conducted to validate the orientation angles of natural fibers using the derived equation. The case study was performed in two molds with one of varying section, and another wide area section and the experimental orientation angles were compared with the numerical predictions. The numerical results of the flow front and velocity distribution obtained from simulation software were compared with digitized images of the flow front from the experimental method. The natural fibers have improved the strength and modulus of the composites. The composite specimens were produced for different compositions of sisal fiber using compression-molding process and the mechanical properties of the composites were studied. An increase in tensile strength, tear strength, and improved hardness was observed in sisal fiber composites. The morphological study using X-ray tomography and Scanning electron microscopy (SEM) has shown the defects, and the fiber orientation. Short fiber reinforced polymer composites (SFRPC) produced by injection molding process have established a commercial utilization in all sectors due to low cost and lower weight of the components. The polymers are reinforced with natural fibers to improve their performance. The orientation of short natural fibers in the polymer composite influences the mechanical performance. This research thus focused on the prediction of natural fiber orientation using a theoretical model and then studied the mechanical properties of natural fiber reinforced composites. The theoretical model was derived by incorporating the shape factor of natural fibers into the angular velocity of the fluid element in order to predict the orientation during the injection molding process. The ANSYS- FLUENT software was used to find the velocity distribution in the fluid domain, from which the angular velocity of the fluid element and the orientation angle were found numerically. This numerical orientation result was then compared to the experimental data. The orientation angle of rigid particles rotating at a fixed distance from the inlet gate was measured by an experimental method where a transparent cavity was filled through an injection molding process An experimental setup was developed to study the orientation behavior of short natural fibers in the flowing viscous fluid. Two experimental case studies were conducted to validate the orientation angles of natural fibers using the derived equation. The case study was performed in two molds with one of varying section, and another wide area section and the experimental orientation angles were compared with the numerical predictions. The numerical results of the flow front and velocity distribution obtained from simulation software were compared with digitized images of the flow front from the experimental method. The natural fibers have improved the strength and modulus of the composites. The composite specimens were produced for different compositions of sisal fiber using compression-molding process and the mechanical properties of the composites were studied. An increase in tensile strength, tear strength, and improved hardness was observed in sisal fiber composites. The morphological study using X-ray tomography and Scanning electron microscopy (SEM) has shown the defects, and the fiber orientation.

Download or read book Flow Induced Alignment in Composite Materials written by T. D. Papathanasiou and published by Woodhead Publishing. This book was released on 1997-10-21 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of aligning short fibers in a fiber-reinforced material is to improve the mechanical properties of the resulting composite. Aligning the fibers, generally in a preferred direction, allows them to contribute as much as possible to reinforcing the material. In some cases, the mechanical properties of these aligned, short-fiber composites can approach those of continuous-fiber composites, with the advantages of lower production costs and greater ease of production. Since its publication, this book has been consistently recognized as one of the most important contributions to this field.

Download or read book Science and Engineering of Short Fibre Reinforced Polymer Composites written by Shao-yun Fu and published by Woodhead Publishing. This book was released on 2019-08-24 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: Science and Engineering of Short Fibre Reinforced Polymer Composites, Second Edition, provides the latest information on the ‘short fiber reinforced composites' (SFRP) that have found extensive applications in automobiles, business machines, durable consumer items, sporting goods and electrical industries due to their low cost, easy processing and superior mechanical properties over parent polymers. This updated edition presents new developments in this field of research and includes new chapters on electrical conductivity, structural monitoring, functional properties, self-healing, finite element method techniques, multi-scale SFRCs, and both modern computational and process engineering methods. Reviews the mechanical properties and functions of short fiber reinforced polymer composites (SFRP) Examines recent developments in the fundamental mechanisms of SFRP's Assesses major factors affecting mechanical performance, such as stress transfer and strength Includes new chapters on electrical conductivity, structural monitoring, functional properties, self-healing, finite element method techniques, multi-scale SFRCs, modern computational methods, and process engineering methods

Download or read book Direct Processing of Long Fiber Reinforced Thermoplastic Composites and their Mechanical Behavior under Static and Dynamic Load written by Melanie Rohde-Tibitanzl and published by Carl Hanser Verlag GmbH Co KG. This book was released on 2015-12-07 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanical behavior of fiber reinforced thermoplastic composites is mainly influenced by fiber length. However, fiber length is strongly reduced during processing. For this reason direct processing techniques are increasingly applied in order to avoid fiber fracture and thus to generate composites with long fibers. This work investigates the influence of fiber length especially on fatigue behavior of thermoplastic composites. The processing influences on fiber length of composites during injection molding compounding are thereby analyzed and quantified. It is thus shown how to directly influence fiber length in the composite.

Download or read book Experimentation on Fiber Orientation in Injection Molded Short fiber Reinforced Composites written by Robert Boyd Davis and published by . This book was released on 1988 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polypropylene Handbook written by József Karger-Kocsis and published by Springer. This book was released on 2019-03-18 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book extensively reviews Polypropylene (PP), the second most widely produced thermoplastic material, having been produced for over 60 years. Its synthesis, processing and application are still accompanied by vigorous R&D developments because the properties of PP are at the borderline between those of commodity and engineering thermoplastics. Readers are introduced to various tacticities and polymorphs of PP, and their effects on structural properties. Further, the book addresses the control of optical properties using nucleants, provides strategies for overcoming the limited cold/impact resistance of PP, examines in detail the effects of recycling, and presents guidelines for the property modification of PPs through foaming, filling and reinforcing with respect to target applications. Special attention is paid to descriptions and models of properties as a function of morphological variables. Last but not least, the book suggests potential practical applications of PP-based systems, especially in the packaging, appliances, building/construction, textile and automotive sectors. Each chapter, written by internationally respected scientists, reflects the current state-of-art in the respective field and offers a vital source of information for students, researchers and engineers interested in the morphology, properties, testing and modeling of PP and PP-based systems. The content is indispensable to the appropriate application of PPs and related composites.

Download or read book Fiber Orientation Analysis of Long Glass Fiber Reinforced Polypropylene in Injection Molded Spiral Flow written by and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis and Performance of Fiber Composites written by Bhagwan D. Agarwal and published by Wiley-Interscience. This book was released on 1990-10-08 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Having fully established themselves as workable engineering materials, composite materials are now increasingly commonplace around the world. Serves as both a text and reference guide to the behavior of composite materials in different engineering applications. Revised for this Second Edition, the text includes a general discussion of composites as material, practical aspects of design and performance, and further analysis that will be helpful to those engaged in research on composites. Each chapter closes with references for further reading and a set of problems that will be useful in developing a better understanding of the subject.

Download or read book Rheology of Filled Polymer Systems written by A.V. Shenoy and published by Springer Science & Business Media. This book was released on 1999-01-31 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rheology of filled polymer systems is an ever expanding field in the polymer industry today. Using a concise, practical and simple format this comprehensive work explains the concepts behind filled polymer systems and the rheological techniques involved in studying their behaviour. Aware that the readers of the book may come from differing background, the first three chapters familiarize the reader with the basics about polymers, fillers and physicochemical interactions between them, rheology and rheometry. Covering such topics as preparation of filled polymer systems, steady shear viscous properties and extentional flow properties, this book covers the areas of importance from an introductory level through to more complex issues.

Download or read book Flow Induced Alignment in Composite Materials written by T.D. Papathanasiou and published by Woodhead Publishing. This book was released on 2021-10-19 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of aligning short fibers in a fiber-reinforced material is to improve the mechanical properties of the resulting composite. Aligning the fibers, generally in a preferred direction, allows them to contribute as much as possible to reinforcing the material. The first edition of this book detailed, in a single volume, the science, processing, applications, characterization and properties of composite materials reinforced with short fibers that have been orientated in a preferred direction by flows arising during processing. The technology of fiber-reinforced composites is continually evolving and this new edition provides timely and much needed information about this important class of engineering materials. Each of the original chapters have been brought fully up-to-date and new developments such as: the advent of nano-composites and the issues relating to their alignment; the wider use of long-fiber composites and the appearance of models able to capture their orientation during flow; the wider use of flows in micro-channels in the context of composites fabrication; and the increase in computing power, which has made relevant simulations (especially coupling flow kinematics to fiber content and orientation) much easier to perform are all covered in detail. The book will be an essential up-to-date reference resource for materials scientists, students, and engineers who are working in the relevant areas of particulate composites, short fiber-reinforced composites or nanocomposites. Presents recent progress on flow-induced alignment, modelling and design of fiber and particulate filled polymer composites Discusses important advances such as alignment of CNTs in polymer nanocomposites and molecular alignment of polymers induced by the injection molding process in the presence of fillers such as short fibers Presents fiber interaction/diffusion modelling and also the fiber flexure/breakage models

Download or read book Fiber Orientation in Injection Molded Composites written by Randy Scott Bay and published by . This book was released on 1991 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental measurements of fiber orientation are reported for two parts injection molded from nylon 6/6 reinforced with 43 weight percent of glass fibers. The parts are a center-gated disk and a film-gated strip. Orientation is measured from polished cross-sections and reported as a function of position, both across the thickness and in the flow direction. Both parts have a layered structure, with outer shell layers of flow-aligned fibers surrounding a central core of either random-in-plane (strip) or transversely aligned fibers (disk). The experiments are compared to predictions of a finite difference simulation of the mold filling problem. The simulation predicts the presence, nature and location of the layers very well. However, it overpredicts the small out-of-plane fiber orientation and places the core-shell transition too close to the midplane. A comparison with selected experimental results suggests that the major source of error is the closure approximation used by the fiber orientation equation. The simulation is exercised for a variety of cases to show the importance of material and process parameters. Injection time is an important parameter, but injection temperature and mold temperature have little effect on fiber orientation. A method is presented to predict the thermo-mechanical properties of injection molded composites. The property predictions suggest that current accuracy of orientation predictions in injection molding is not adequate to accurately predict these properties. To improve the accuracy of the orientation predictions a new closure approximation is developed. When used to predict orientation in injection moldings, this new closure approximation predicts correctly the small out-of-plane fiber orientation and places the core-shell transition further from the midplane, but the core layer is still predicted to be thinner than in the experiments. It appears that the transient behavior of the theory is limiting how accurately the location of the transition is predicted. Experimental results from the shell region of injection molded strips are compared with distribution function results; the comparison demonstrates clearly that the interaction coefficient decreases as the volume fraction of the fibers increases. An empirical model based on these results relates the interaction coefficient to the fiber concentration and aspect ratio.

Download or read book Improved Fiber Orientation Predictions for Injection Molded Composites written by Jin Wang and published by . This book was released on 2007 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: Short fibers are commonly utilized to reinforce the polymer matrix for injection molded parts. Fibers suspended in the molten polymer matrix are oriented by the flow during the mold filling process, and acquire a preferential orientation pattern in the final part. The fiber orientation introduces anisotropy to the mechanical and thermal properties of the material, including the elastic modulus, the tensile strength, and the thermal expansion. A final part is stronger and stiffer in the direction along which the most fibers align, while it is weaker and more compliant in the other directions. An accurate prediction of fiber orientation in injection molding is crucial for designing a mold and controlling part properties. The well-established Folgar, Advani, and Tucker model is widely used to predict fiber orientation. However, recent experiments indicate that this theory overestimates the change rate of the fiber orientation tensor, and therefore predicts a similar orientation pattern in injection-molded parts regardless of the flow length, the part thickness, or the mold filling speed. A strain reduction factor (SRF) was introduced by Huynh (2001) to decrease the change rate of orientation tensor. Though it produces an excellent agreement with experimental data, the SRF model is not objective and encounters difficulty in complex flows. Inspired by the idea of reducing the growth rates of the eigenvalues of the orientation tensor by a scalar factor, a new orientation model was built, in which we modified the closure and fiber-fiber interactions terms accordingly. A possible approach to reduce the rotation rates of the eigenvectors was also explored, but no successful model with this feature was found. A finite difference program was developed and used to simulate the filling process for two simple geometries: end-gated strips and center-gated disks. The program is based upon the Hele-Shaw approximation to solve the velocity field, and implements the new orientation model to predict the fiber orientation. The results using the same scalar factor as the SRF model show an excellent agreement with experimental measurements, for both strips and disks, in small thicknesses and at different filling speeds. A special treatment was proposed for thick strips, to account for the radial flow front that is observed in short-shot experiments and is different from the almost flat flow front in thin strips. The finite difference program was also extended to simulate the filling process of injection molds with rotation, compression, and expansion (RCEM). The comparison of the predicted and measured fiber orientation demonstrates again the usefulness of our new orientation model. The new orientation theory was further implemented to model complex flows where the full equations of motion must be solved. The solver of fiber orientation equations was added to FIDAP(TM), a commercial finite element software, through user subroutines. The final program is able to solve for velocity, temperature, pressure, and fiber orientation in any two- or three-dimensional geometry. Flow through the gate of our end-gated strips was simulated, and the fiber orientation was calculated. The orientation results were compared to the measured values at a region just inside the gate, and then were used as inlet conditions for the finite difference program to successfully predict the downstream orientation. Our new orientation model is aphenomenological theory, and the value of the scalar factor to reduce the orientation change rate is determined by matching experimental data. Since the rheology of a fiber suspension is affected by the fiber orientation, a rheological experiment measuring the shear viscosity and the normal stress difference is one approach to determine the phenomenological parameters. The formulations were worked out for the shear stress and the normal stress difference with respect to the fiber orientation in a parallel-disk rotational rheometer, and the model was fit to the measured values in a least square sense by adjusting the model parameters. This provides a convenient and viable route for determining the parameters of the orientation model.

Download or read book Hybrid Natural Fiber Composites written by Anish Khan and published by Woodhead Publishing. This book was released on 2021-01-21 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research on natural fiber composites is an emerging area in the field of polymer science with tremendous growth potential for commercialization. Hybrid Natural Fiber Composites: Material Formulations, Processing, Characterization, Properties, and Engineering Applications provides updated information on all the important classes of natural fibers and their composites that can be used for a broad range of engineering applications. Leading researchers from industry, academia, government, and private research institutions from across the globe have contributed to this highly application-oriented book. The chapters showcase cutting-edge research discussing the current status, key trends, future directions, and opportunities. Focusing on the current state of the art, the authors aim to demonstrate the future potential of these materials in a broad range of demanding engineering applications. This book will act as a one-stop reference resource for academic and industrial researchers working in R&D departments involved in designing composite materials for semi structural engineering applications. Presents comprehensive information on the properties of hybrid natural fiber composites that demonstrate their ability to improve the hydrophobic nature of natural fiber composites Reviews recent developments in the research and development of hybrid natural fiber composites in various engineering applications Focuses on modern technologies and illustrates how hybrid natural fiber composites can be used as alternatives in structural components subjected to severe conditions

Download or read book Composite Reinforcements for Optimum Performance written by Philippe Boisse and published by Woodhead Publishing. This book was released on 2020-10-22 with total page 730 pages. Available in PDF, EPUB and Kindle. Book excerpt: Composite Reinforcements for Optimum Performance, Second Edition, has been brought fully up to date with the latest developments in the field. It reviews the materials, properties and modelling techniques used in composite production and highlights their uses in optimizing performance. Part I covers materials for reinforcements in composites, including chapters on fibers, carbon nanotubes and ceramics as reinforcement materials. In Part II, different types of structures for reinforcements are discussed, with chapters covering woven and braided reinforcements, three-dimensional fibre structures and two methods of modelling the geometry of textile reinforcements: WiseTex and TexGen. Part III focuses on the properties of composite reinforcements, with chapters on topics such as in-plane shear properties, transverse compression, bending and permeability properties. Finally, Part IV covers the characterization and modelling of reinforcements in composites, with chapters focusing on microscopic and mesoscopic approaches, X-ray tomography analysis and modelling reinforcement forming processes. With its distinguished editor and international team of contributors, Composite Reinforcements for Optimum Performance, Second Edition, is an essential reference for designers and engineers working in the composite and composite reinforcement manufacturing industry, as well as all those with an academic research interest in the subject. Discusses the characterization and modeling of reinforcements in composites, focusing on such topics as microscopic and mesoscopic approaches, X-ray tomography analysis, and modeling reinforcement forming processes Provides comprehensive coverage of the types and properties of reinforcement in composites, along with their production and performance optimization Includes sections on NCF (non-crimp fabrics), natural fiber reinforcements, tufting composite reinforcements, sustainability, multiscale modeling, knitted reinforcements, and more

Download or read book Peterson s Stress Concentration Factors written by Walter D. Pilkey and published by John Wiley & Sons. This book was released on 2020-01-07 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt: The bible of stress concentration factors—updated to reflect today's advances in stress analysis This book establishes and maintains a system of data classification for all the applications of stress and strain analysis, and expedites their synthesis into CAD applications. Filled with all of the latest developments in stress and strain analysis, this Fourth Edition presents stress concentration factors both graphically and with formulas, and the illustrated index allows readers to identify structures and shapes of interest based on the geometry and loading of the location of a stress concentration factor. Peterson's Stress Concentration Factors, Fourth Edition includes a thorough introduction of the theory and methods for static and fatigue design, quantification of stress and strain, research on stress concentration factors for weld joints and composite materials, and a new introduction to the systematic stress analysis approach using Finite Element Analysis (FEA). From notches and grooves to shoulder fillets and holes, readers will learn everything they need to know about stress concentration in one single volume. Peterson's is the practitioner's go-to stress concentration factors reference Includes completely revised introductory chapters on fundamentals of stress analysis; miscellaneous design elements; finite element analysis (FEA) for stress analysis Features new research on stress concentration factors related to weld joints and composite materials Takes a deep dive into the theory and methods for material characterization, quantification and analysis methods of stress and strain, and static and fatigue design Peterson's Stress Concentration Factors is an excellent book for all mechanical, civil, and structural engineers, and for all engineering students and researchers.

Download or read book Cellulose Fibers Bio and Nano Polymer Composites written by Susheel Kalia and published by Springer Science & Business Media. This book was released on 2011-04-11 with total page 743 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because we are living in an era of Green Science and Technology, developments in the field of bio- and nano- polymer composite materials for advanced structural and medical applications is a rapidly emerging area and the subject of scientific attention. In light of the continuously deteriorating environmental conditions, researchers all over the world have focused an enormous amount of scientific research towards bio-based materials because of their cost effectiveness, eco-friendliness and renewability. This handbook deals with cellulose fibers and nano-fibers and covers the latest advances in bio- and nano- polymer composite materials. This rapidly expanding field is generating many exciting new materials with novel properties and promises to yield advanced applications in diverse fields. This book reviews vital issues and topics and will be of interest to academicians, research scholars, polymer engineers and researchers in industries working in the subject area. It will also be a valuable resource for undergraduate and postgraduate students at institutes of plastic engineering and other technical institutes.