Download or read book Simulation and Validation of Mold Filling During Compression Resin Transfer Molding CRTM Process written by Prabhas M. Bhat and published by ProQuest. This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In Compression Resin Transfer Molding (CRTM), the fiber preform is placed in the mold; the top of the mold is lowered until there is a small gap between the preform and the mold. The measured amount of resin is injected through one or more gates into this highly permeable gap. Then the resin injection is switched off and the mold is closed by moving the mold platen towards the preform until it reaches the desired thickness. This action compresses the preform and pressurizes the resin to flow into the preform and occupy the empty regions between the fibers. This process is very attractive for high volume production of net shape composite structures and is being considered by automobile manufacturing industry for structural components. The challenge is to create void free structures with reasonable applied force with filling times of the order of a few minutes. A model and simulation of the process can help identify the important parameters in the process that will aid in achieving this goal. An existing numerical simulation that can model the RTM process has been modified to accommodate the presence of gap elements, compression of preform and reduction of mesh size during the process. The process is modeled in three stages: (i) resin injection into the gap, (ii) closing of the gap with negligible compression of the preform and (iii) preform compaction. An analysis of the process has been conducted to identify the important non-dimensional parameters that influence the process. A parametric study reveals the relationship between the material, process and the geometric variables in this process. To validate the numerical model, an experimental set-up was constructed. The set-up includes a semi cylindrical transparent mold which is compressed using pressurized water in a collapsible tube. Independent experiments are conducted to measure the permeability of the fabric and the force required for compression. Various process parameters such as the location of the resin front during the compression, the rate of compression and the force are recorded as a function of time. These results are compared with the simulation to gauge the accuracy of the model and the reliability in the characterization of the material parameters. This simulation should prove useful in development of process inputs for large scale structures to produce void free parts with optimal compression rates and pressures.

Download or read book Process simulation of wet compression moulding for continuous fibre reinforced polymers written by Poppe, Christian Timo and published by KIT Scientific Publishing. This book was released on 2022-07-18 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interdisciplinary development approaches for system-efficient lightweight design unite a comprehensive understanding of materials, processes and methods. This applies particularly to continuous fibre-reinforced plastics (CoFRPs), which offer high weight-specific material properties and enable load path-optimised designs. This thesis is dedicated to understanding and modelling Wet Compression Moulding (WCM) to facilitate large-volume production of CoFRP structural components.

Download or read book Advanced Fibre Reinforced Polymer FRP Composites for Structural Applications written by Jiping Bai and published by Woodhead Publishing. This book was released on 2022-12-05 with total page 844 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Fibre-reinforced Polymer (FRP) Composites for Structural Applications, Second Edition provides updates on new research that has been carried out on the use of FRP composites for structural applications. These include the further development of advanced FRP composites materials that achieve lighter and stronger FRP composites, how to enhance FRP integrated behavior through matrix modification, along with information on pretension treatments and intelligence technology. The development of new technology such as automated manufacturing and processing of fiber-reinforced polymer (FRP) composites have played a significant role in optimizing fabrication processing and matrix formation. In this new edition, all chapters have been brought fully up-to-date to take on the key aspects mentioned above. The book's chapters cover all areas relevant to advanced FRP composites, from the material itself, its manufacturing, properties, testing and applications in structural and civil engineering. Applications span from civil engineering, to buildings and the energy industry. - Covers all areas relevant to advanced FRP composites, from the material itself, its manufacturing, properties, testing and applications in structural engineering - Features new manufacturing techniques, such as automated fiber placement and 3D printing of composites - Includes various applications, such as prestressed-FRP, FRP made of short fibers, continuous structural health monitoring using advanced optical fiber Bragg grating (FBG), durability of FRP-strengthened structures, and the application of carbon nano-tubes or platelets for enhancing durability of FRP-bonded structures

Download or read book Resin Transfer Moulding for Aerospace Structures written by T. Kruckenberg and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resin Transfer Moulding and other similar 'liquid moulding' manufacturing methods have been used to make non-structural composites for the last 35 years. However, in the last eight years these methods have become the subject of enormous interest by aerospace manufacturing companies. Resin Transfer Moulding for Aerospace Structures describes all aspects of Resin Transfer Moulding (RTM) for aerospace structures. Written by an international team of experts, from both industry and academia, it is a comprehensive work providing complete and detailed information on the process of RTM from theoretical modelling to practical experience. With subjects including manufacturing, tooling, fabric design and flow modelling all covered, this book is an invaluable up-to-the-minute reference source which provides the reader with a good understanding of RTM and its possible uses, especially for high performance applications. Resin Transfer Moulding for Aerospace Structures is an ideal guide for those in the aerospace and related industries, who want to understand and utilize RTM, as well as those directly involved in the RTM industry.

Download or read book Liquid Moulding Technologies written by C D Rudd and published by Elsevier. This book was released on 1997-01-01 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid moulding technologies such as RTM and SRIM are increasingly used for manufacturing composites in a variety of industries. Most interest stems from the automotive industry in the continuing search for weight savings, manufacturing economies and vehicle refinement.Liquid Moulding Technologies provides a unique insight into the development and use of such processes with a comprehensive description of the material, process variants, equipment, control strategies and tooling techniques used. Procedures for materials characterisation, preform and mould design are also described and the text is augmented by a number of case studies for prototype and production parts.This book is an invaluable source for both industrial moulders and those working in research and development.

Download or read book Mesoscale simulation of the mold filling process of Sheet Molding Compound written by Meyer, Nils and published by KIT Scientific Publishing. This book was released on 2022-07-12 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sheet Molding Compounds (SMC) are discontinuous fiber reinforced composites that are widely applied due to their ability to realize composite parts with long fibers at low cost. A novel Direct Bundle Simulation (DBS) method is proposed in this work to enable a direct simulation at component scale utilizing the observation that fiber bundles often remain in a bundled configuration during SMC compression molding.

Download or read book An Efficient Analysis of Resin Transfer Molding Process Using Extended Finite Element Method written by Yeonhee Jung and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical simulation for Resin Transfer Molding (RTM) manufacturing process is attempted by using the eXtended Finite Element Method (XFEM) combined with the level set method. XFEM allows to obtaining a good numerical precision of the pressure near the resin flow front, where its gradient is discontinuous. The enriched shape functions of XFEM are derived by using the level set values so as to correctly describe the interpolation with the resin flow front. In addition, the level set method is used to transport the resin flow front at each time step during the mold filling. The level set values are calculated by an implicit characteristic Galerkin FEM. The multi-frontal solver of IPSAP is adopted to solve the system. This work is validated by comparing the obtained results with analytic solutions.Moreover, a localization method of XFEM and level set method is proposed to increase the computing efficiency. The computation domain is reduced to the small region near the resin flow front. Therefore, the total computing time is strongly reduced by it. The efficiency test is made with simple channel or radial flow models. Several application examples are analyzed to demonstrate ability of this method. A wind turbine blade is also treated as industrial application. Finally, a Graphic User Interface (GUI) tool is developed so as to make easy the pre/post-processing of the simulation.

Download or read book Verification of a Three Dimensional Resin Transfer Molding Process Simulation Model written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-23 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental evidence was obtained to complete the verification of the parameters needed for input to a three-dimensional finite element model simulating the resin flow and cure through an orthotropic fabric preform. The material characterizations completed include resin kinetics and viscosity models, as well as preform permeability and compaction models. The steady-state and advancing front permeability measurement methods are compared. The results indicate that both methods yield similar permeabilities for a plain weave, bi-axial fiberglass fabric. Also, a method to determine principal directions and permeabilities is discussed and results are shown for a multi-axial warp knit preform. The flow of resin through a blade-stiffened preform was modeled and experiments were completed to verify the results. The predicted inlet pressure was approximately 65% of the measured value. A parametric study was performed to explain differences in measured and predicted flow front advancement and inlet pressures. Furthermore, PR-500 epoxy resin/IM7 8HS carbon fabric flat panels were fabricated by the Resin Transfer Molding process. Tests were completed utilizing both perimeter injection and center-port injection as resin inlet boundary conditions. The mold was instrumented with FDEMS sensors, pressure transducers, and thermocouples to monitor the process conditions. Results include a comparison of predicted and measured inlet pressures and flow front position. For the perimeter injection case, the measured inlet pressure and flow front results compared well to the predicted results. The results of the center-port injection case showed that the predicted inlet pressure was approximately 50% of the measured inlet pressure. Also, measured flow front position data did not agree well with the predicted results. Possible reasons for error include fiber deformation at the resin inlet and a lag in FDEMS sensor wet-out due to low mold pressures. Fingerson, John C. and Loos, Alfred C. and ...

Download or read book A Sensitivity based Gate Location Algorithm for Optimal Mold Filling During the Resin transfer Molding RTM Process written by Roopesh Mathur and published by . This book was released on 2002 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: A sensitivity-based gate location algorithm for optimal filling of molds in the resin-transfer molding (RTM) process is described in this report. In the RTM process for composite manufacturing, a fiber preform is placed inside a mold and resin is injected into it under high pressures through inlets or gates. Finite-element-based resin-flow simulation codes have been successfully used for modeling and analysis of the process. This process is increasingly used for the manufacture of three-dimensional (3-D) composite parts with material and geometric complexities. In such cases, the locations of the gates cannot be determined easily except by expensive trial and error, both experimentally and computationally. Hence, systematic search methods working in tandem with flow simulations are necessary to determine gate locations for optimal filling. In this report, the governing equation for pressure along with the boundary conditions is differentiated with respect to the coordinates of each gate. The resulting system of pressure sensitivity fields is solved in parallel with the flow problem. The sensitivity fields are used to compute the gradients of the fill time with respect to the gate's coordinates. A standard gradient-based optimization algorithm is then used to determine the new coordinates of the gate location. This methodology of finding optimal gate locations for mold filling in RTM was demonstrated with a case study in which mold-filling time was minimized for the case of a single gate.

Download or read book A Sensitivity based Gate Location Algorithm for Optimal Mold Filling During the Resin transfer Molding RTM Process written by Roopesh Mathur and published by . This book was released on 2002 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: A sensitivity-based gate location algorithm for optimal filling of molds in the resin-transfer molding (RTM) process is described in this report. In the RTM process for composite manufacturing, a fiber preform is placed inside a mold and resin is injected into it under high pressures through inlets or gates. Finite-element-based resin-flow simulation codes have been successfully used for modeling and analysis of the process. This process is increasingly used for the manufacture of three-dimensional (3-D) composite parts with material and geometric complexities. In such cases, the locations of the gates cannot be determined easily except by expensive trial and error, both experimentally and computationally. Hence, systematic search methods working in tandem with flow simulations are necessary to determine gate locations for optimal filling. In this report, the governing equation for pressure along with the boundary conditions is differentiated with respect to the coordinates of each gate. The resulting system of pressure sensitivity fields is solved in parallel with the flow problem. The sensitivity fields are used to compute the gradients of the fill time with respect to the gate's coordinates. A standard gradient-based optimization algorithm is then used to determine the new coordinates of the gate location. This methodology of finding optimal gate locations for mold filling in RTM was demonstrated with a case study in which mold-filling time was minimized for the case of a single gate.

Download or read book Molding Simulation Theory and Practice written by Maw-Ling Wang and published by Carl Hanser Verlag GmbH Co KG. This book was released on 2022-06-07 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: This practical introductory guide to injection molding simulation is aimed at both practicing engineers and students. It will help the reader to innovate and improve part design and molding processes, essential for efficient manufacturing. A user-friendly, case-study-based approach is applied, enhanced by many illustrations in full color. The book is conceptually divided into three parts: Chapters 1–5 introduce the fundamentals of injection molding, and how molding simulation methodology is developed, especially focusing on the effects on molding quality from the rheological, thermodynamic, thermal, mechanical, and kinetic properties of plastics, as well as curing kinetics for thermoset plastics. Chapters 6–11 introduce CAE verification on injection molding including design guidelines of part, gating, runner, and cooling channel systems. Temperature control in hot runner systems, prediction and control of warpage, and fiber orientation are also discussed. Chapters 12–17 introduce research and development in innovative molding, illustrating how CAE is applied to advanced molding techniques, including co-/bi-injection molding, gas-/water-assisted injection molding, foam injection molding, powder injection molding, resin transfer molding (RTM), and integrated circuit (IC) packaging. The 2nd edition contains many updates, including elaboration of material measurement data, connection of Smart Design and Smart Manufacturing, demonstration of the flow-induced fiber orientation effect, implementations of material characterization methods on PU reactive foaming and RTM, studies of dispensing control and creeping behaviors effects on IC underfill process, and much more. Several CAE case study exercises for execution in Moldex3D software are included to allow readers to practice what they have learned and test their understanding.

Download or read book Development and Validation of Simulation Software for RTM and VARTM Process written by Peter Jong Ho Kim and published by . This book was released on 2009 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transport Phenomena in Liquid Composite Molding Processes written by João M.P.Q. Delgado and published by Springer. This book was released on 2019-01-29 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides valuable information on polymer composite manufacturing, with a focus on liquid molding processes and the resin transfer molding technique (RTM). It presents and discusses emerging topics related to the foundations, engineering applications, advanced modeling and experiments regarding the RTM process. A valuable resource for engineers, professionals in industry and academics involved in this advanced interdisciplinary field, it also serves as a comprehensive reference book for undergraduate and postgraduate courses.

Download or read book Methodologies for Resin Flow Prediction and Manipulation in Liquid Composite Molding Processes written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Resin Transfer Molding (RTM) process has gained popularity amongst composite manufacturers due to the surface quality and dimensional tolerances that can be achieved from this process. In this process, fiber preforms are placed in a rigid mold and resin is injected through a gate to fill the empty spaces between the fibers. Being a closed mold process, one cannot view the progression of flow during the filling stage. It has been commonplace that parts would contain regions unsaturated by resin. Not only would these parts have to be discarded, there was no knowledge as to how these unsaturated regions formed, and what to do to prevent repeat occurrence. Typically, a trial and error process is employed to attempt to correct for the problem. By modeling the RTM process as flow through anisotropic porous media, one can simulate and predict the flow in the mold if the permeability of the fiber is known. However, during the preform preparation or handling the permeability along mold edges varies from one point to the next. It was discovered that disturbances inside the mold led to alterations in the flow progression. The approach taken in this dissertation will be to manipulate the flow progression by selectively opening and closing gates during the filling process. The goal of the manipulation is to direct the flow in such a manner that despite the disturbances, one will be able to completely saturate the fibers with resin. The variation in flow progression is investigated and characterized using simulations. The fundamentals of flow manipulation are described with an introductory example. The true approach. A study quantifies the disturbance range and frequency in common manufacturing practice. With the nature of the disturbances better understood, several flow manipulation approaches were developed and compared. These approaches proved to be successful in the virtual manufacturing domain, but required experimental validation. Therefore, an experimental workstation was designed and built to accommodate the needs of the approaches. The workstation was used, and demonstrated the strengths and weaknesses of the various approaches.

Download or read book Flow Analysis with Fiber Preform Deformation During Compression Resin Transfer Molding written by Justin Merotte and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Compression resin transfer molding (CRTM) is an alternative solution to conventional resin transfer molding processes. It offers the capability to produce net shape composites with fast cycle times making it conducive for high volume production. The resin flow during this process can be separated into three phases; (i) metered amount of resin injection into a partially closed mold containing dry fiber preform, (ii) closure of the mold until it is in contact with the fiber preform displacing all the resin into the preform and (iii) further mold closure to the desired thickness of the part compacting the preform and redistributing the resin. Understanding the flow behavior in every phase is imperative for predictive process modeling that guarantees full preform saturation within a given time and under specified force constraints. In this thesis, the CRTM flow is modeled as a two dimensional flow in a gradually deformed porous medium during all three phases. The governing equations are formulated and coupled with the constitutive equations that describe the deformation and permeability behavior. Due to the non-linear nature of coupled system of equations, a numerical solution is developed that describes the flow front progression and the preform deformation during the process. A non dimensional analysis is conducted in which the applied force and initial gap size emerge as the important process variables that influence the process cycle time. Limiting cases are identified which reduce the flow to one dimensional flow for which a simplified solution is developed. The results are verified using an experimental setup whichapplies a constant force to the preform in a transparent mold allowing one to track the flow front. This study quantifies the effect of preform deformation due to the fluid pressure and should prove useful in applications that involve fluid impregnation in deforming porous media.

Download or read book Manufacturing Techniques for Polymer Matrix Composites PMCs written by Suresh G Advani and published by Elsevier. This book was released on 2012-07-18 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymer matrix composites are used extensively across a wide range of industries, making the design and development of effective manufacturing processes of great importance. Manufacturing techniques for polymer matrix composites (PMCs) provides an authoritative review of the different technologies employed in the manufacture of this class of composite.Following an introduction to composites and manufacturing processes, part one reviews the manufacturing of short fiber and nanoparticle based polymer matrix composites, with injection and compression molding examined in depth. Thermoplastic processing is the focus of part two. Sheet forming, fabric thermostamping, filament winding and continuous fiber reinforced profiles are investigated. Part three reviews thermoset processing. A survey of resin transfer molding follows, including vacuum-assisted and compression resin transfer molding. The pultrusion process is then considered, before the book concludes with an investigation into autoclave and out-of-autoclave curing processes in polymer matrix composites.With its distinguished editors and international team of expert contributors, Manufacturing techniques for polymer matrix composites (PMCs) is an essential guide for engineers and scientists working in the field of polymer matrix composites. - Provides an authoritative review of the different technologies employed in the manufacture of polymer matrix composites - Reviews the manufacturing of short fiber and nanoparticle-based polymer matrix composites, with injection and compression molding examined in depth - Examines thermoplastic processing, sheet forming, fabric thermostamping, filament winding and continuous fiber reinforced profiles

Download or read book ASC Series on Advances in Composite Materials written by Alfred C. Loos and published by DEStech Publications, Inc. This book was released on 2013 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains 16 original papers on the processing and manufacturing of thermoset and thermoplastic composites. In this book, nine chapters cover modeling and process parameters for many shapes of thermosets using RTM, VARTM and CRTM.