The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
J. G. Vaughan - One of the best experts on this subject based on the ideXlab platform.
-
Enhanced Pultrusion Using Photocure to Supplement Standard Thermal Cure
2020Co-Authors: E. Lackey, J. G. VaughanAbstract:The rapid cure that occurs when photointiated resins are exposed to light of the appropriate wavelength offers the potential for the use of photocure to improve the processing efficiency for the Pultrusion process. The objective of this research is to demonstrate the feasibility of a photocure Pultrusion process that utilizes standard Pultrusion tooling and equipment. In order to accomplish this objective, a hybrid thermal/photo initiator process which uses photocure to supplement standard thermal cure was developed. Results demonstrate the potential offered by this hybrid thermal/photo initiator process; exposure to UV energy lead to an increase in degree of cure and mechanical properties in the thermal/photo initiated composites.
-
Die Inlet Contour Impact on the Pressure Rise in a Pultrusion Die
Journal of Composite Materials, 2000Co-Authors: K. S. Raper, T. A. Mccarty, J. A. Roux, J. G. VaughanAbstract:The quality of a pultruded composite depends on many process control parameters and variables. The pressure rise in the Pultrusion die inlet is one such variable which can impact the quality of a pultruded product. An appreciable die inlet pressure rise can suppress void formation and enhance fiber "wet out." In this study, a model based on Darcy's law for flow in a porous medium and which employs the finite volume solution method is developed to predict the pressure and velocity fields as a function of various die inlet contours. Investigating the behavior of the pressure rise in the Pultrusion die inlet as a function of the shape of the die inlet contour can be a very useful and effective tool for analyzing and designing Pultrusion die inlets. Various die inlet contours such as the wedge, circular tapered die inlet, and some hypothetical die inlet contours were investigated to determine the impact on die inlet pressure rise. The original contributions of this paper are results which are useful for desig...
-
Permeability Impact on the Pressure Rise in a Pultrusion Die
Journal of Thermophysics and Heat Transfer, 1999Co-Authors: K. S. Raper, J. G. Vaughan, J. A. Roux, E. LackeyAbstract:The pressure rise in a Pultrusion die inlet can have a significant impact on the quality of a pultruded product; therefore, a model to predict the pressure rise would be a very useful and effective tool for enhancing the Pultrusion process and the pultruded product. There are several parameters that can strongly affect the pressure rise in the Pultrusion die inlet. One particular parameter is the permeability. In this study, three permeability models are employed to investigate their effect on the pressure rise in the Pultrusion die inlet. A numerical model, based on Darcy's law for flow in a porous media that employs the finite volume solution method, is developed to predict the pressure and velocity fields in the Pultrusion die. The numerical results are compared with some preliminary experimental data for both glass and graphite composites to determine which permeability model agrees best with the data. An effective fiber diameter is introduced to account for nonuniform fiber diameters and nonuniform spatial fiber distributions.
-
Investigation of the pressure behavior in a Pultrusion die for graphite/epoxy composites
Composites Part A-applied Science and Manufacturing, 1999Co-Authors: K. S. Raper, Jeffrey A. Roux, T. A. Mccarty, J. G. VaughanAbstract:Abstract There are a variety of ways to process composite materials. One such way is Pultrusion which is a continuous process for manufacturing composite materials of constant cross-sections. The Pultrusion process involves a number of variables and processing parameters which can affect the quality of a pultruded product. One variable of particular interest is the fluid resin pressure rise in the tapered inlet region of the die. The liquid resin pressure rise in the die inlet can have a significant impact on the quality of a pultruded product. An appreciable pressure rise can suppress void formations and enhance fiber “wet out”. Darcy’s law for flow in a porous media is used to mathematically model the fiber/resin system of the Pultrusion process, while employing the finite volume solution method to predict the pressure and velocity fields as a function of various process control parameters. The results obtained by the numerical model can establish a foundation by which process control parameters are selected to achieve an appreciable pressure rise which will enhance the quality of the pultruded composite. The results can also be applied to die inlet design.
-
Comparison of Measurements and Modeling for Pultrusion of a Fiberglass/Epoxy I-Beam
Journal of Reinforced Plastics and Composites, 1998Co-Authors: Jeffrey A. Roux, J. G. Vaughan, R. Shanku, E. S. Arafat, J. L. Bruce, V. R. JohnsonAbstract:This research presents the experimental characterization and modeling of three-dimensional unsteady-state temperature and degree of cure distributions for the Pultrusion manufacturing of fiberglass-epoxy I-beam composites. The model is capable of predicting temperature and degree of cure distributions for composites with Cartesian shapes in three dimensions and temperature profiles in Pultrusion dies without the aid of predetermined temperature values used as die wall boundary conditions. The numerical model is compared with experimentally measured temperatures and degrees of cure recorded during the actual Pultrusion manufacturing of the fiberglass-epoxy I-beams. Using a differential scanning calorimeter (DSC), the die composite exit degree of cure was also obtained. The finite volume method was utilized in the development of the numerical model for solving the governing energy and species equations used in modeling the entire heating section of the pultruder. The combinations of pull speed, fiber volume, and die temperature profiles can be modeled very economically to simulate Pultrusion manufacturing of composites. Since this research is not limited in terms of predetermined temperature values, it can be tailored easily to predict a multitude oftemperature profiles suited for a Pultrusion process. This research is also important because it provides realistic modeling of irregular cross-sectional geometries.
Ismet Baran - One of the best experts on this subject based on the ideXlab platform.
-
Numerical modeling of the mechanics of Pultrusion
Mechanics of Materials in Modern Manufacturing Methods and Processing Techniques, 2020Co-Authors: Michael Sandberg, Ismet Baran, Onur Yuksel, Raphaël Comminal, Mads Rostgaard Sonne, Masoud Jabbari, Martin Larsen, Filip Bo Salling, Jon Spangenberg, Jesper Henri HattelAbstract:Abstract This chapter concerns numerical modeling of the mechanics of Pultrusion processes, with a focus on the physics that takes place inside the Pultrusion die. The following topics are covered: (1) impregnation mechanisms of saturated and unsaturated flow to predict the resin impregnation and pressure rise in straight and tapered impregnation chambers; (2) thermochemical (TC) modeling, which concerns the development of temperature and degree of cure throughout the Pultrusion die; (3) TC-mechanical modeling for analyzing process-induced shape distortions and associated stresses and strains; and finally (4) methods for estimating the required pulling force to achieve the desired profile-advancing pulling speed.
-
Investigation of the thermal contact resistance in thermosetting Pultrusion process
2017Co-Authors: Ismet Baran, Cem Celal Tutum, Jesper Henri HattelAbstract:Introduction Pultrusion process is one of the most effective methods for production of composite materials with having constant cross-sectional profiles such as beams, stiffeners, tubes etc. This process has been widely used for manufacturing highly strengthened and continuous composite structures. The fascinating point of the Pultrusion process is the productivity and low cost. A schematic view of the Pultrusion process can be seen in Fig. 1.
-
The impact of process parameters on the residual stresses and distortions in Pultrusion
2017Co-Authors: Ismet Baran, Jesper Henri Hattel, Cem Celal TutumAbstract:1 General Introduction Pultrusion is a manufacturing process for producing continuous lengths of fiber reinforced composite shapes with a constant cross section. While Pultrusion machines vary in design, the process is basically the same. Fibers and resin materials are pulled through a heated forming die using a continuous pulling system and the cured profile is cut into its final length. A schematic view of the Pultrusion process can be seen in Fig. 1.
-
Probabilistic modelling of the process induced variations in Pultrusion
2017Co-Authors: Ismet Baran, Jesper Henri Hattel, Cem Celal TutumAbstract:1 General Introduction Manufacturing processes introduce several sources of uncertainties into the material properties as well as the dimensions of the final product. Hence, stochastic modeling of manufacturing processes has a great potential to improve the understanding of the variation in the final properties owing to the inherent uncertainties in the process. In this respect, instead of having a purely deterministic model, a stochastic model is used in combination with a deterministic model for the simulation of the Pultrusion process in the present paper. Pultrusion is a continuous and a cost effective composite manufacturing process in which constant cross sectional profiles are produced. Since the pultruded profiles are foreseen to be used more frequently in several industries such as construction, wind energy etc., it is necessary to take the uncertainties coming from the Pultrusion process into account to evaluate the level of variation of the desired final properties or dimensions of the product. A schematic view of the Pultrusion process is shown in Fig. 1.
-
Pultrusion of a vertical axis wind turbine blade part-I: 3D thermo-chemical process simulation
International Journal of Material Forming, 2015Co-Authors: Ismet Baran, Cem C. Tutum, Jesper H. Hattel, Remko AkkermanAbstract:A novel three dimensional thermo-chemical simulation of the Pultrusion process is presented. A simulation is performed for the Pultrusion of a NACA0018 blade profile having a curved geometry, as a part of the DeepWind project. The finite element/nodal control volume (FE/NCV) technique is used. First, a Pultrusion simulation of a U-shaped composite profile is performed to validate the model and it is found that the obtained cure degree profiles match with those given in the literature. Subsequently, the Pultrusion process simulation of the NACA0018 profile is performed. The evolutions of the temperature and cure degree distributions are predicted inside the heating die and in the post-die region where convective cooling prevails. The effects of varying process conditions on the part quality are investigated for two different heater configurations and with three different pulling speeds. Larger through-thickness gradients are obtained for the temperature and degree of cure as the pulling speed increases. This will affect the process induced residual stresses and distortions during manufacturing.
R.b. Pipes - One of the best experts on this subject based on the ideXlab platform.
-
Internet controlled thermoplastic impregnation of glass fibers yarns with Pultrusion
2020Co-Authors: Ozgu Ozturk, Justin Molenaur, R.b. PipesAbstract:The process for thermoplastic Pultrusion of glass fiber yarns is controlled with data acquisition software via the Internet. Consisting of the fiber distribution system with the guidance device, extruder, impregnation chamber, cooling unit, pulling mechanism, and take up device, the Pultrusion line is operated and/or monitored remotely to obtain optimum performance.
-
Optimization of thermoplastic impregnation of glass fiber yarns with Pultrusion
2020Co-Authors: Ozgu Ozturk, Michael Stadler, R.b. PipesAbstract:The influence of process variables on the degree of thermoplastic impregnation of glass fiber yarns by Pultrusion is investigated. The performance of the Pultrusion line consisting of fiber distribution system, guidance device, extruder, impregnation chamber, cooling unit, pulling mechanism, and take-up device is examined in order to evaluate variable sensitivity and to optimize the process for pulling speed.
-
Development of a facility for Pultrusion of thermoplastic-matrix composites
Composites Manufacturing, 2008Co-Authors: B. Tomas Åström, Per H. Larsson, R.b. PipesAbstract:Abstract An experimental facility for Pultrusion of thermoplastic-matrix composites has been designed and built. Unidirectionally reinforced composites have been manufactured and composite temperature and pressure distributions and process pulling forces have been experimentally determined. The Pultrusion facility is described in detail and the experimental results are discussed in terms of operating parameters and die design.
-
A modeling approach to thermoplastic Pultrusion. II: Verification of models
Polymer Composites, 1993Co-Authors: B. Tomas Åström, R.b. PipesAbstract:A fundamental understanding of the effects of processing parameters and die geometry in a Pultrusion process requires a mathematical model in order to minimize the number of necessary experiments. Previous investigators have suggested a variety of models for thermoset Pultrusion, while comparatively little effort has been spent modeling its less well understood thermoplastic counterpart. Herein, models to describe temperature and pressure distributions within a thermoplastic composite as it travels through the Pultrusion line are presented. The temperature model considers heat transfer in an infinite slab with either prescribed boundary temperature, or prescribed heat flux from the surfaces. The pressure model is based upon matrix flow relative to the fibers and incorporates a non-Newtonian matrix viscous, compaction, and friction resistance, is also presented. The models are evaluated studying and ideal Pultrusion process for manufacturing of unidirectional carbon-fiber-reinforced polyether ehterketone composites.
-
Modeling of a thermoplastic Pultrusion process
1991Co-Authors: B.t. Astroem, R.b. PipesAbstract:To obtain a fundamental understanding of the effects of processing parameters and die geometry in a Pultrusion process, a mathematical model is essential in order to minimize the number of trial-and-error experiments. Previous investigators have suggested a variety of more or less complete models for thermoset Pultrusion, while little effort seems to have been spent modeling its less well-understood thermoplastic equivalent. Hence, a set of intricately related models to describe the temperature and pressure distributions, as well as the matrix flow, in a thermoplastic composite as it travels through the Pultrusion die is presented. An approach to calculate the accumulated pulling force is also explored, and the individual mechanisms contributing to the pulling force are discussed. The pressure model incorporates a matrix viscosity that varies with shear rate, temperature, and pressure. Comparisons are made between shear-rate-dependent and Newtonian viscosity representations, indicating the necessity of including non-Newtonian fluid behavior when modeling thermoplastic Pultrusion. The governing equations of the models are stated in general terms, and simplifications are implemented in order to obtain solutions without extensive numerical efforts. Pressure, temperature, cooling rate, and pulling force distributions are presented for carbon-fiber-reinforced polyetheretherketone. Pulling force predictions are compared to data obtained from preliminary experimentsmore » conducted with a model Pultrusion line that was built solely for the Pultrusion of thermoplastic matrix composites, and the correlation is found to be qualitatively satisfactory.« less
G Mennig - One of the best experts on this subject based on the ideXlab platform.
-
Pultrusion of a flax polypropylene yarn
Composites Part A-applied Science and Manufacturing, 2007Co-Authors: I Angelov, S Wiedmer, M Evstatiev, K Friedrich, G MennigAbstract:The present work reports the Pultrusion of a flax reinforced polypropylene commingled yarn containing discontinuous flax and polypropylene fibers. This was the first attempt to pultrude this material. Rectangular cross-sectional profiles have been successfully produced using a self-designed Pultrusion line. In a series of experiments carried out with yarns of two different flax fiber contents, the Pultrusion parameters were varied. In particular, the preheating and die temperatures and also the pulling speed, which are the most relevant parameters regarding the potential future Pultrusion of natural fiber composite profiles at industrial scale. A complete characterization of each profile was conducted in order to examine the influence of processing parameters on the profile quality. The mechanical properties were evaluated by performing three point bending as well as Charpy impact tests.
-
Pultrusion of a flax/polypropylene yarn
Composites Part A-applied Science and Manufacturing, 2007Co-Authors: I Angelov, S Wiedmer, M Evstatiev, K Friedrich, G MennigAbstract:The present work reports the Pultrusion of a flax reinforced polypropylene commingled yarn containing discontinuous flax and polypropylene fibers. This was the first attempt to pultrude this material. Rectangular cross-sectional profiles have been successfully produced using a self-designed Pultrusion line. In a series of experiments carried out with yarns of two different flax fiber contents, the Pultrusion parameters were varied. In particular, the preheating and die temperatures and also the pulling speed, which are the most relevant parameters regarding the potential future Pultrusion of natural fiber composite profiles at industrial scale. A complete characterization of each profile was conducted in order to examine the influence of processing parameters on the profile quality. The mechanical properties were evaluated by performing three point bending as well as Charpy impact tests.
Sunil C. Joshi - One of the best experts on this subject based on the ideXlab platform.
-
The Pultrusion process for polymer matrix composites
Manufacturing Techniques for Polymer Matrix Composites (PMCs), 2014Co-Authors: Sunil C. JoshiAbstract:Abstract: Pultrusion is a continuous process for manufacturing composites with constant cross-sections or structural profiles having significantly long length. It is widely employed in the composites industry due to its continuous, automated and highly productive nature. This chapter presents a comprehensive study that covers the description, market, industry, innovations, variants and literature review of the Pultrusion process technology. The first section gives an overview of the Pultrusion process, its market and its history. The second section provides a detailed description on each component, the materials and the operations of Pultrusion. Section three covers the literature review on various experimental and computational analyses of Pultrusion. The fourth section encompasses the industrial standards, applications, patents, global markets and future trends of Pultrusion process and pultruded products. The fifth section closes the chapter with concluding remarks.
-
Time-Variant Simulation of Multi-Material Thermal Pultrusion
Applied Composite Materials, 2011Co-Authors: Sunil C. Joshi, X. ChenAbstract:Pultrusion being the viable and economical process for producing constant cross-section composite products, many variants of it are being tried out. This paper embarks on the Pultrusion with multi-materials; typically of polymer foam/glass fibre reinforced polymer (GFRP) sandwich panels. Unlike conventional composites Pultrusion, this process with more than two material phases, one of them dry, poses a challenge in simulating the thermal co-curing within the die. In this paper, the formulation and development of three-dimensional, finite element/nodal control volume (FE/NCV) approach for such multi-material Pultrusion is presented. The numerical features for handling the dry-wet material interfaces, material shrinkage, variations in pull speed and die heating, and foam-to-skin thickness ratio are discussed. Implementation of the FE/NCV procedure and its application in analyzing Pultrusion of polymer foam/GFRP sandwich panels with multi-heater environment are presented.
-
integrated approach for modelling cure and crystallization kinetics of different polymers in 3d Pultrusion simulation
Journal of Materials Processing Technology, 2006Co-Authors: Sunil C. JoshiAbstract:Abstract Pultrusion is one of the many manufacturing processes used for fabricating polymer composites. Both, thermosetting resins and thermoplastics are used as polymer matrices in Pultrusion. Behaviour of these two types of polymers in a Pultrusion die is different from each other and requires a different numerical strategy to simulate their reaction kinetics. In this paper the three-dimensional, finite element/nodal control volume (FE/NCV) approach for simulation of thermosetting and thermoplastic composites Pultrusion is discussed. The numerical schemes developed for modelling the curing of a thermosetting matrix and the crystallization of a thermoplastic binder are presented. Implementation of these schemes in the FE/NCV procedure is discussed. Finally, simulation case studies on the Pultrusion of Glass/EPON 9420 and APC-2 CF/PEEK with multi-heater, steel die assemblies are presented.
