Letteratura scientifica selezionata sul tema "Formulation filament"
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Articoli di riviste sul tema "Formulation filament"
1
Roulon, Stéphane, Ian Soulairol, Valérie Lavastre, Nicolas Payre, Maxime Cazes, Laurent Delbreilh e Jean Alié. "Production of Reproducible Filament Batches for the Fabrication of 3D Printed Oral Forms". Pharmaceutics 13, n. 4 (31 marzo 2021): 472. http://dx.doi.org/10.3390/pharmaceutics13040472.
Testo completoAbstract (sommario):
Patients need medications at a dosage suited to their physiological characteristics. Three-dimensional printing (3DP) technology by fused-filament fabrication (FFF) is a solution for manufacturing medication on demand. The aim of this work was to identify important parameters for the production of reproducible filament batches used by 3DP for oral formulations. Amiodarone hydrochloride, an antiarrhythmic and insoluble drug, was chosen as a model drug because of dosage adaptation need in children. Polyethylene oxide (PEO) filaments containing amiodarone hydrochloride were produced by hot-melt extrusion (HME). Different formulation storage conditions were investigated. For all formulations, the physical form of the drug following HME and fused-deposition modeling (FDM) 3D-printing processes were assessed using thermal analysis and X-ray powder diffraction (XRPD). Filament mechanical properties, linear mass density and surface roughness, were investigated by, respectively, 3-point bending, weighing, and scanning electron microscopy (SEM). Analysis results showed that the formulation storage condition before HME-modified filament linear mass density and, therefore, the oral forms masses from a batch to another. To obtain constant filament apparent density, it has been shown that a constant and reproducible drying condition is required to produce oral forms with constant mass.
2
Kennedy, Daniel T., e Robert A. Van Gorder. "Motion of open vortex-current filaments under the Biot–Savart model". Journal of Fluid Mechanics 836 (12 dicembre 2017): 532–59. http://dx.doi.org/10.1017/jfm.2017.826.
Testo completoAbstract (sommario):
Vortex-current filaments have been used to study phenomena such as coronal loops and solar flares as well as tokamaks, and recent experimental work has demonstrated dynamics akin to vortex-current filaments on a table-top plasma focus device. While MHD vortex dynamics and related applications to turbulence have attracted consideration in the literature due to a wide variety of applications, not much analytical progress has been made in this area, and the analysis of such vortex-current filament solutions under various geometries may motivate further experimental efforts. To this end, we consider the motion of open, isolated vortex-current filaments in the presence of magnetohydrodynamic (MHD) as well as the standard hydrodynamic effects. We begin with the vortex-current model of Yatsuyanagi, Hatori & Kato (J. Phys. Soc. Japan, vol. 65, 1996, pp. 745–759) giving the self-induced motion of a vortex-current filament. We give the ‘cutoff’ formulation of the Biot–Savart integrals used in this model, to avoid the singularity at the vortex core. We then study the motion of a variety of vortex-current filaments, including helical, planar and self-similar filament structures. In the case where MHD effects are weak relative to hydrodynamic effects, the filaments behave as expected from the pure hydrodynamic theory. However, when MHD effects are strong enough to dominate, then we observe structural changes to the filaments in all cases considered. The most common finding is reversal of vortex-current filament orientation for strong enough MHD effects. Kelvin waves along a vortex filament (as seen for helical and self-similar structures) will reverse their translational and rotational motion under strong MHD effects. Our findings support the view that vortex-current filaments can be studied in a manner similar to classical hydrodynamic vortex filaments, with the primary role of MHD effects being to change the filament motion, while preserving the overall geometric structure of such filaments.
3
Walker, B. J., K. Ishimoto, H. Gadêlha e E. A. Gaffney. "Filament mechanics in a half-space via regularised Stokeslet segments". Journal of Fluid Mechanics 879 (1 ottobre 2019): 808–33. http://dx.doi.org/10.1017/jfm.2019.723.
Testo completoAbstract (sommario):
We present a generalisation of efficient numerical frameworks for modelling fluid–filament interactions via the discretisation of a recently developed, non-local integral equation formulation to incorporate regularised Stokeslets with half-space boundary conditions, as motivated by the importance of confining geometries in many applications. We proceed to utilise this framework to examine the drag on slender inextensible filaments moving near a boundary, firstly with a relatively simple example, evaluating the accuracy of resistive force theories near boundaries using regularised Stokeslet segments. This highlights that resistive force theories do not accurately quantify filament dynamics in a range of circumstances, even with analytical corrections for the boundary. However, there is the notable and important exception of movement in a plane parallel to the boundary, where accuracy is maintained. In particular, this justifies the judicious use of resistive force theories in examining the mechanics of filaments and monoflagellate microswimmers with planar flagellar patterns moving parallel to boundaries. We proceed to apply the numerical framework developed here to consider how filament elastohydrodynamics can impact drag near a boundary, analysing in detail the complex responses of a passive cantilevered filament to an oscillatory flow. In particular, we document the emergence of an asymmetric periodic beating in passive filaments in particular parameter regimes, which are remarkably similar to the power and reverse strokes exhibited by motile$9+2$cilia. Furthermore, these changes in the morphology of the filament beating, arising from the fluid–structure interactions, also induce a significant increase in the hydrodynamic drag of the filament.
4
Moreau, Clément, Laetitia Giraldi e Hermes Gadêlha. "The asymptotic coarse-graining formulation of slender-rods, bio-filaments and flagella". Journal of The Royal Society Interface 15, n. 144 (luglio 2018): 20180235. http://dx.doi.org/10.1098/rsif.2018.0235.
Testo completoAbstract (sommario):
The inertialess fluid–structure interactions of active and passive inextensible filaments and slender-rods are ubiquitous in nature, from the dynamics of semi-flexible polymers and cytoskeletal filaments to cellular mechanics and flagella. The coupling between the geometry of deformation and the physical interaction governing the dynamics of bio-filaments is complex. Governing equations negotiate elastohydrodynamical interactions with non-holonomic constraints arising from the filament inextensibility. Such elastohydrodynamic systems are structurally convoluted, prone to numerical errors, thus requiring penalization methods and high-order spatio-temporal propagators. The asymptotic coarse-graining formulation presented here exploits the momentum balance in the asymptotic limit of small rod-like elements which are integrated semi-analytically. This greatly simplifies the elastohydrodynamic interactions and overcomes previous numerical instability. The resulting matricial system is straightforward and intuitive to implement, and allows for a fast and efficient computation, more than a hundred times faster than previous schemes. Only basic knowledge of systems of linear equations is required, and implementation achieved with any solver of choice. Generalizations for complex interaction of multiple rods, Brownian polymer dynamics, active filaments and non-local hydrodynamics are also straightforward. We demonstrate these in four examples commonly found in biological systems, including the dynamics of filaments and flagella. Three of these systems are novel in the literature. We additionally provide a Matlab code that can be used as a basis for further generalizations.
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Regnier, J., C. Cloarec, A. Cayla, C. Campagne e E. Devaux. "Multifilaments based on partially miscible polymers blend filled with carbon nanotubes". IOP Conference Series: Materials Science and Engineering 1266, n. 1 (1 gennaio 2023): 012020. http://dx.doi.org/10.1088/1757-899x/1266/1/012020.
Testo completoAbstract (sommario):
Abstract Many textile fields, such as industrial structures or clothing, use the electrical conductivity variation of yarns to detect fluid leakage. Such yarns can be developed by melt spinning conductive polymer composites (CPC). CPC filaments are composed of a polymer’s matrix which is blended with sufficient quantity of electrically conductive fillers to make the filament conductive. To combine properties or improve the compounds preparation, more and more studies are investigating different polymers blends. In this study, CPC monofilaments and multifilaments are developed and characterized to observe the formulation influence on spinnability and the implementation process on the water detection. Two principles of water detection are studied on the CPC which is composed of a blend of partially miscible polymers (polyethylene terephthalate (PET)/polybutylene terephthalate (PBT)) filled with carbon nanotubes (CNT). The principle of absorption is based on the electrical conductivity variation of the filament in contact with water. For the short circuit principle, the presence of the liquid is detected when the water creates a conductive path between two filaments in parallel.
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Varan, Cem, Davut Aksüt, Murat Şen e Erem Bilensoy. "Design and Characterization of Carboplatin and Paclitaxel Loaded PCL Filaments for 3D Printed Controlled Release Intrauterine Implants". Pharmaceutics 15, n. 4 (5 aprile 2023): 1154. http://dx.doi.org/10.3390/pharmaceutics15041154.
Testo completoAbstract (sommario):
Uterine cancer is the fourth most common cancer in women. Despite various chemotherapy approaches, the desired effect has not yet been achieved. The main reason is each patient responds differently to standard treatment protocols. The production of personalized drugs and/or drug-loaded implants is not possible in today’s pharmaceutical industry; 3D printers allow for the rapid and flexible preparation of personalized drug-loaded implants. However, the key point is the preparation of drug-loaded working material such as filament for 3D printers. In this study, two different anticancer (paclitaxel, carboplatin) drug-loaded PCL filaments with a 1.75 mm diameter were prepared with a hot-melt extruder. To optimize the filament for a 3D printer, different PCL Mn, cyclodextrins and different formulation parameters were tried, and a series of characterization studies of filaments were conducted. The encapsulation efficiency, drug release profile and in vitro cell culture studies have shown that 85% of loaded drugs retain their effectiveness, provide a controlled release for 10 days and cause a decrease in cell viability of over 60%. In conclusion, it is possible to prepare optimum dual anticancer drug-loaded filaments for FDM 3D printers. Drug-eluting personalized intra-uterine devices can be designed for the treatment of uterine cancer by using these filaments.
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Padilla, Marcel, Oliver Gross, Felix Knöppel, Albert Chern, Ulrich Pinkall e Peter Schröder. "Filament based plasma". ACM Transactions on Graphics 41, n. 4 (luglio 2022): 1–14. http://dx.doi.org/10.1145/3528223.3530102.
Testo completoAbstract (sommario):
Simulation of stellar atmospheres, such as that of our own sun, is a common task in CGI for scientific visualization, movies and games. A fibrous volumetric texture is a visually dominant feature of the solar corona---the plasma that extends from the solar surface into space. These coronal fibers can be modeled as magnetic filaments whose shape is governed by the magnetohydrostatic equation. The magnetic filaments provide a Lagrangian curve representation and their initial configuration can be prescribed by an artist or generated from magnetic flux given as a scalar texture on the sun's surface. Subsequently, the shape of the filaments is determined based on a variational formulation. The output is a visual rendering of the whole sun. We demonstrate the fidelity of our method by comparing the resulting renderings with actual images of our sun's corona.
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Van Gorder, Robert A. "Helical vortex filament motion under the non-local Biot–Savart model". Journal of Fluid Mechanics 762 (3 dicembre 2014): 141–55. http://dx.doi.org/10.1017/jfm.2014.639.
Testo completoAbstract (sommario):
AbstractThe thin helical vortex filament is one of the fundamental exact solutions possible under the local induction approximation (LIA). The LIA is itself an approximation to the non-local Biot–Savart dynamics governing the self-induced motion of a vortex filament, and helical filaments have also been considered for the Biot–Savart dynamics, under a variety of configurations and assumptions. We study the motion of such a helical filament in the Cartesian reference frame by determining the curve defining this filament mathematically from the Biot–Savart model. In order to do so, we consider a matched approximation to the Biot–Savart dynamics, with local effects approximated by the LIA in order to avoid the logarithmic singularity inherent in the Biot–Savart formulation. This, in turn, allows us to determine the rotational and translational velocity of the filament in terms of a local contribution (which is exactly that which is found under the LIA) and a non-local contribution, each of which depends on the wavenumber, $k$, and the helix diameter, $A$. Performing our calculations in such a way, we can easily compare our results to those of the LIA. For small $k$, the transverse velocity scales as $k^{2}$, while for large $k$, the transverse velocity scales as $k$. On the other hand, the rotational velocity attains a maximum value at some finite $k$, which corresponds to the wavenumber giving the maximal torsion.
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Prasad, Elke, John Robertson e Gavin W. Halbert. "An Additive Manufacturing MicroFactory: Overcoming Brittle Material Failure and Improving Product Performance through Tablet Micro-Structure Control for an Immediate Release Dose Form". Polymers 16, n. 18 (11 settembre 2024): 2566. http://dx.doi.org/10.3390/polym16182566.
Testo completoAbstract (sommario):
Additive manufacturing of pharmaceutical formulations offers advanced micro-structure control of oral solid dose (OSD) forms targeting not only customised dosing of an active pharmaceutical ingredient (API) but also custom-made drug release profiles. Traditionally, material extrusion 3D printing manufacturing was performed in a two-step manufacturing process via an intermediate feedstock filament. This process was often limited in the material space due to unsuitable (brittle) material properties, which required additional time to develop complex formulations to overcome. The objective of this study was to develop an additive manufacturing MicroFactory process to produce an immediate release (IR) OSD form containing 250 mg of mefenamic acid (MFA) with consistent drug release. In this study, we present a single-step additive manufacturing process employing a novel, filament-free melt extrusion 3D printer, the MicroFactory, to successfully print a previously ‘non-printable’ brittle Soluplus®-based formulation of MFA, resulting in targeted IR dissolution profiles. The physico-chemical properties of 3D printed MFA-Soluplus®-D-sorbitol formulation was characterised by thermal analysis, Fourier Transform Infrared spectroscopy (FTIR), and X-ray Diffraction Powder (XRPD) analysis, confirming the crystalline state of mefenamic acid as polymorphic form I. Oscillatory temperature and frequency rheology sweeps were related to the processability of the formulation in the MicroFactory. 3D printed, micro-structure controlled, OSDs showed good uniformity of mass and content and exhibited an IR profile with good consistency. Fitting a mathematical model to the dissolution data correlated rate parameters and release exponents with tablet porosity. This study illustrates how additive manufacturing via melt extrusion using this MicroFactory not only streamlines the manufacturing process (one-step vs. two-step) but also enables the processing of (brittle) pharmaceutical immediate-release polymers/polymer formulations, improving and facilitating targeted in vitro drug dissolution profiles.
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Shia, C. Y., R. J. Stango e S. M. Heinrich. "Analysis of Contact Mechanics for a Circular Filamentary Brush/Workpart System". Journal of Manufacturing Science and Engineering 120, n. 4 (1 novembre 1998): 715–21. http://dx.doi.org/10.1115/1.2830211.
Testo completoAbstract (sommario):
This paper addresses the contact problem associated with the filament/workpart interaction that arises during brushing processes. A discretized model of a filament within the brushing tool is developed by employing Lagrange’s equations in conjunction with special constraint equations that are appropriate for the impact and impending large displacement of a flexible fiber whose tip traverses a flat, rigid surface. This formulation leads to the identification of five nondimensional parameters which fully characterize the filament/workpart contact problem. A damping mechanism is also included which can be used for modeling complex filament interactions that arise during the actual brushing operation. Special consideration is given to examining the initial filament/workpart impact and the subsequent forces that are generated along the contact region. Initial velocity of the filament is determined by employing an inelastic impact mechanics analysis. Time-varying transient response of the filament is then obtained by employing a predictor-corrector technique in conjunction with a finite difference method. Overall brush force is computed by a superposition of filament contact forces exerted onto the workpart surface. Numerical results are reported and compared with experimentally obtained data for an actual brush/workpart system.
Tesi sul tema "Formulation filament"
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Lacorne, Jordan. "Fabrication additive par fil fondu d’un acier martensitique : Formulation du fil et étude du déliantage/frittage". Electronic Thesis or Diss., Lyon, INSA, 2024. http://www.theses.fr/2024ISAL0112.
Testo completoAbstract (sommario):
Le procédé FFF (Fused Filament Fabrication) est une technique de fabrication additive pour créer des pièces métalliques à moindre coût. Il comprend plusieurs étapes : l’élaboration et la fabrication des filaments composé d’une matrice polymère et de poudre métallique, l’impression des pièces dites vertes, le déliantage consiste à retirer la matrice polymère soit par dissolution par solvant, soit par dégradation thermique, le frittage densifie les pièces laissées poreuses après le déliantage. L’entreprise Nanoe, spécialisée dans les filaments céramiques, cherche à étendre son expertise aux pièces métalliques, notamment en acier H13. L’optimisation des formulations ainsi que l’amélioration des étapes de post-impression sont primordiaux pour la technologie FFF. L’objectif principal de cette thèse était de caractériser l’ensemble du procédé afin de l’améliorer. Pour cela, les travaux de thèse se sont articulés autour de trois axes : déterminer les propriétés mécaniques et rhéologiques requises pour obtenir des filaments imprimables ; optimiser le déliantage tout en évitant l’apparition des défauts ou des contaminations ; obtenir des pièces denses. L’étude de l’influence des modules de stockage G’ et de perte G” sur l’écoulement du feedstock lors de l’impression et la tenue de la pièce lors du déliantage a permis de définir les additifs utilisés dans le feedstock. Puis, L’optimisation du déliantage vise à réduire le temps de cycle tout en prévenant les défauts. Un nouveau cycle de déliantage a été mis au point, tenant compte des températures de dégradation des liants et des vitesses adaptées. Enfin, les recherches ont approfondi les paramètres de frittage de l’acier H13, en observant les effets sur la porosité et la microstructure, notamment grâce à des suivis dilatométriques et des analyses au MEB. Les résultats ont permis de mieux comprendre les mécanismes de densification et l’impact du taux de carbone sur la microstructure finaleThe FFF (Fused Filament Fabrication) process is an additive manufacturing technique for creating low-cost metal parts. It comprises several stages: the development and manufacture of filaments composed of a polymer matrix and metal powder, the printing of so-called green parts, debinding, which consists in removing the polymer matrix either by solvent dissolution or thermal degradation, and sintering, which densifies the parts left porous after debinding. Nanoe, which specializes in ceramic filaments, is looking to extend its expertise to metal parts, particularly in H13 steel. Optimizing formulations and improving post-printing steps are of prime importance for FFF technology. The main objective of this thesis was to characterize the entire process in order to improve it. To this end, the thesis work focused on three areas: determining the mechanical and rheological properties required to obtain printable filaments; optimizing debinding while avoiding the appearance of defects or contamination; and obtaining dense parts. A study of the influence of storage modulus G' and loss modulus G” on feedstock flow during printing and part strength during debinding enabled us to define the additives used in the feedstock.Then, the optimization of debinding aims to reduce cycle time while preventing defects. A new debinding cycle was developed, taking into account binder degradation temperatures and adapted speeds. Finally, the research focused on the sintering parameters of H13 steel, observing the effects on porosity and microstructure, notably through dilatometric monitoring and SEM analysis. The results provided a better understanding of densification mechanisms and the impact of carbon content on the final microstructure
Libri sul tema "Formulation filament"
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Barack, Obama, e United States. Congress. House. Committee on Foreign Affairs, a cura di. Certification for an export to the People's Republic of China: Message from the President of the United States transmitting certification that the export of one continuous mixer to be used to manufacture conductive polymer compounds to be further processed to make circuit protection devices, one jet mill to be used for particle size reduction of pigments and other powder products for cosmetic formulations, and one filament winding cell to be used to manufacture fiberglass assembly shelter poles for use in tents and shelters is not detrimental to the U.S. space launch industry and will not measurably improve the missile or space launch capabilities of the People's Republic of China, pursuant to Pub. L. 105-261, sec. 1512. Washington: U.S. G.P.O., 2009.
Cerca il testo completoCapitoli di libri sul tema "Formulation filament"
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De Bernardez, Leopoldo, Giampaolo Campana, Mattia Mele e Sebastian Mur. "Towards a Comparative Index Assessing Mechanical Performance, Material Consumption and Energy Requirements for Additive Manufactured Parts". In Lecture Notes in Mechanical Engineering, 302–10. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-28839-5_34.
Testo completoAbstract (sommario):
AbstractThe increasing use of Additive Manufacturing technologies and systems in several industrial sectors and their numerous applications turn the attention of scientists and investigators to studying and evaluating the environmental impacts of these processes. Additive Manufacturing generally allows for a reduction of raw material consumption and waste generation. On the other hand, the need for long processing times and the necessary thermal conditioning of the manufacturing chamber to avoid product defects, lead to a considerable amount of consumed energy per produced item. Energy consumption has been a primary concern of the research on the sustainability of Additive Manufacturing indeed. More recent studies extended the analysis through more complete evaluation methods such as the Life Cycle Assessment. This approach allows a detailed description of environmental impacts but is affected by some concerns about the need for an interpretation of the final results, which can be non-univocal. This fact is particularly critical when the assessment is intended to be used for comparison between alternative solutions.In this study, a novel index is introduced including three main aspects: material consumption, energy requirements and mechanical performance. The proposed formulation makes the index immediately usable for comparing alternative solutions. Within the scope of this study, the index has been applied to one of the most widespread Additive Manufacturing processes, namely Fused Filament Fabrication. The presented case study demonstrates the suitability of the proposed method to compare and identify the optimal choice among alternative manufacturing scenarios.
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Tian, Jing, Yanyan Zheng, Qing Ouyang, Ping Xue, Baohua Guo e Jun Xu. "Structure and Properties of Biodegradable Polymer Materials for Fused Deposition Modeling 3D Printing". In Advances in 3D Printing [Working Title]. IntechOpen, 2023. http://dx.doi.org/10.5772/intechopen.110175.
Testo completoAbstract (sommario):
The properties of 3D printed products are closely related to the raw materials and the processes by which they are made. The processes of melting, depositing, and cooling of polymers affect the orientation, crystallinity, and microstructure of the product. These in turn influence the thermal, mechanical, optical, and other properties of the printed part. Among various 3D printing methods, filament and pellet extrusion-based fused deposition modeling (FDM) 3D printing is the cheapest and mostly adopted. In this chapter, the devices and some biodegradable polymer materials applicable in FDM 3D printing are briefly introduced. In the first part, preparation and the structure-property relationship of polylactic acid/polybutylene succinate blend filaments are discussed. Rheological, thermal properties of the raw materials and the properties of the printed parts were characterized. In the second part, a pellet extrusion 3D printer with a micro-screw was designed for using pellets of polyhydroxyalkanoate composites, which are difficult to produce filaments. The relationship between the screw parameters of the micro-screw extrusion 3D printer, rheological properties of the composites, and the printed product performance has been investigated. Combining theory and practical application will provide guidance for formulating biodegradable polymer materials and designing equipment for FDM 3D printing.
Atti di convegni sul tema "Formulation filament"
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Francois, Marianne M., Robert B. Lowrie e Edward D. Dendy. "A Material Interface Transition Algorithm for Multiphase Flow". In ASME 2008 Fluids Engineering Division Summer Meeting collocated with the Heat Transfer, Energy Sustainability, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/fedsm2008-55304.
Testo completoAbstract (sommario):
Volume tracking method, also referred to as the volume-of-fluid (VOF) method introduces “numerical surface tension” that breaks a filament into a series of droplets whenever the filament is under-resolved. Adaptive mesh refinement can help avoid under-resolution, but a fully-developed flow will still generate filaments that cannot be resolved without enormous computational cost. We propose a complementary new approach that consists of transitioning to a continuous interface representation (i.e. without interface reconstruction) in regions of under-resolved interfacial curvature where volume tracking has become erroneous. The price of the continuous interface treatment is a small amount of numerical mass diffusion, even if the physical interface is immiscible. However, we have found that for certain measures, the overall accuracy is greatly improved by using our transitioning algorithm. The algorithm is developed in the context of the single fluid formulation of the incompressible Navier-Stokes equations. Numerical standard vortices advection test cases and Rayleigh-Taylor instability computations are presented to illustrate the transition algorithm potential.
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Yoshikawa, Nobuhiro. "Optimum Design of Net Reinforced Composite Pressure Vessel". In ASME/JSME 2004 Pressure Vessels and Piping Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/pvp2004-2269.
Testo completoAbstract (sommario):
A new breed of structural reinforcement for high pressure vessels is proposed by netted filament, whereas the conventional composite containers are fabricated with continuous filament winding. An enhancement of design variation is aimed at for light-weight together with adequate structural reliability ensured by means of structural optimization technique in the present study. Modeling the net segments as bar finite elements contacting with the surface of the metallic liner, a shape-finding problem raised by the geometrical non-linearity with the finite rotation of bar element is posed. The problem is solved on the basis of principle of minimum strain energy with respect to nodal position of the element. A formulation is derived to search for the optimum configuration of net reinforcing spherical dome. The optimum length of net segment is determined so as to realize uniform strain in net. Numerical examples validate the proposed formulation.
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Sangli, Aditya N., Austin Hultmark, Graham Aldinger, Ranjeet Rao, David M. Johnson, Ashutos Parhi e Prateek Sharma. "Filament Extension Atomization Spraying of High Concentration Whey Suspensions". In ASME 2022 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/imece2022-97022.
Testo completoAbstract (sommario):
Abstract Conventional spray nozzles are used in industries to atomize fluids for many applications. But these nozzles cannot atomize fluids having large viscosities and non-Newtonian characteristics. Dairy fluids like whey suspensions are examples of such fluids. Nozzles used in atomization of such suspensions for spray drying only operate with fluids having high water content. Atomizing suspensions with low water content will conserve energy by lowering the load on the spray dryer. In this study, we have used Filament Extension Atomization (FEA) technology to spray sweet dry whey suspension at 80% solids loading and Whey Protein Concentrate (WPC 80) at 50% solids loading. These concentrations are 30% above current industrial standards. We present our formulation techniques and non-Newtonian rheology characterization of the suspensions. By spraying the suspensions with FEA, we demonstrate tight control over drop size distribution in the spray with a D50 < 200 μm. Finally, we present a novel design for high throughput spraying of such dairy suspensions to be incorporated into industrial spray dryers.
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Aoki, Yoshio, Akiko Shoji e O.-Il Byon. "Damage Detection of CFRP Pipes and Ladder Structure by Using Localized Flexibility Method". In ASME 2001 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/imece2001/ad-23706.
Testo completoAbstract (sommario):
Abstract This paper presents modal-based structural damage detection. Specifically, we focus on localized flexibility properties that can be deduced from the experimentally determined global flexibility matrix. We present the underlying theory that can be viewed a generalized flexibility formulation in three different generalized coordinates, viz., localized or substructural displacement-basis, elemental deformation-basis and element strain-basis. Then, the present methods are applied to a CFRP pipes and shells having interior damage and the numerical and experimental results show that the elemental strain-basis method is quite useful for detecting the inside damage of the CFRP filament winding pipes.
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NAGARAJ, MANISH, CHRISTOPHER J. HANSEN e MARIANNA MAIARU. "PREDICTION OF DISTORTION AND RESIDUAL STRESS EVOLUTION IN THE FUSED FILAMENT FABRICATION PROCESS USING HIGHER-ORDER FINITE ELEMENTS". In Proceedings for the American Society for Composites-Thirty Eighth Technical Conference. Destech Publications, Inc., 2023. http://dx.doi.org/10.12783/asc38/36698.
Testo completoAbstract (sommario):
This work presents a higher-order finite element-based process modeling framework for material extrusion additive manufacturing. The numerical modeling is based on higher-order structural theories derived via the Carrera Unified Formulation, and allows for high-fidelity modeling in a computationally efficient manner. The element activation strategy is employed to simulate the material deposition process. A thermo-mechanical analysis is performed to determine the evolving temperature field within the part during the printing process, which is subsequently used to evaluate the distortion of the printed structure. Numerical assessments are performed, and the agreement of the numerical predictions with available reference experimental data validates the proposed process modeling framework for additive manufacturing.
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Mortazavi, Mehrad, Venkattraman Ayyaswamy, Arvind Gopinath e Sachin Goyal. "Fluid-Structure Interaction of Slender Biofilaments at Low Reynolds Numbers". In ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-70702.
Testo completoAbstract (sommario):
Abstract Active filamentous organelles such as cilia and flagella oscillate due to the interplay between activity, elasticity, and viscous hydrodynamic drag. The presence of no-slip boundaries also impacts the viscous drag forces on the filament. Recent efforts to develop low Reynolds numbers synthetic swimmers and mixers that mimic the ciliary dynamics have used effective elastic filaments that are animated. The instabilities underlying the spatiotemporal dynamics of such biomimetic filaments are dominated equally by elasticity and fluid-solid viscous interactions. Predicting ensuing patterns requires robust computational models that can capture both large-amplitude elastic deformation of the filaments and associated long-ranged hydrodynamic interactions. To address this coupled elastohydrodynamic problem, we develop a composite framework that combines a computational rod model valid for slender filaments and slender body theory (SBT) that accounts for hydrodynamic interactions. The presence of no-slip boundaries is accounted for by using a wall-corrected slender body theory (W-SBT). We analyze the accuracy of the slender body formulations and compare them to solutions obtained via computational fluid dynamic solvers. SBT and W-SBT are found to be computationally faster than other hydrodynamic models; however, they may not provide accurate solutions for small aspect ratio filaments. The fluid-structure interaction model we present here, provides a starting point to computationally investigate the movements of natural and biomimetic cilia and flagella in the vicinity of plane walls.
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Watson, Olivia, Boston Blake, Steven Pagano e Babak Eslami. "Optimization of Infill Percentage Versus Nozzle Diameter in Fused Deposition Modeling 3D Printing". In ASME 2024 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2024. https://doi.org/10.1115/imece2024-145944.
Testo completoAbstract (sommario):
Abstract Fused Deposition Modeling (FDM) 3D printing has evolved from a prototyping tool to a multifaceted manufacturing technique. To fully harness its capabilities, improving production repeatability, efficiency, and material quality is essential. This study explores the relationship between nozzle diameters and two common filaments: polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS). Nozzle diameter is crucial in FDM 3D printing, influencing print quality, speed, and material flow. However, the impact of varying nozzle diameters on different filaments is underexplored. Our research fills this gap, providing key insights. We found significant differences in print quality and mechanical properties across various nozzle diameters and materials. Smaller nozzles generally produce better quality prints and surface finishes but take longer. Material-specific nozzle selection is important, as some filaments work better with certain nozzle sizes. PLA performs well across various sizes, showing excellent print quality and robustness. ABS is sensitive to larger nozzles due to its high printing temperature needs. Our findings offer valuable guidelines for selecting nozzle sizes tailored to specific filaments, enhancing 3D printing efficiency, precision, and quality. These insights are particularly beneficial for industries like automotive and consumer goods, where precision and customization are crucial. Understanding nozzle diameter and filament dynamics can also lead to advanced printing algorithms and material formulations, optimizing multi-material printing and other complex applications.
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Wang, Liang, Yongxing Wang, Antonio M. Recuero e Ahmed A. Shabana. "Use of ANCF Finite Elements in MBS Textile Applications". In ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/detc2015-46330.
Testo completoAbstract (sommario):
The objective of this investigation is to present a new flexible multibody system (MBS) approach for modeling textile roll-drafting sets used in chemical textile industry. The proposed approach can be used in the analysis of textile materials which have un-common material properties best described by specialized continuum mechanics constitutive models, for instance, the lubricated polyester filament bundles (PFB) presented in this paper. In this investigation, PFB is modeled as a hyper-elastic transversely isotropic material using absolute nodal coordinate formulation (ANCF). The PFB strain energy density function is decomposed into a fully isotropic component and an orthotropic, transversely isotropic component expressed in terms of five invariants of the right Cauchy-Green deformation tensor. Using this energy decomposition, the second Piola-Kirchhoff stress and the elasticity tensors can also be split into isotropic and transversely isotropic parts. Constitutive equations are used to evaluate the generalized material forces associated with the coordinates of three-dimensional fully-parameterized ANCF finite elements. The proposed model allows for modeling the dynamic interaction between the rollers and PFB and allows for using spline functions to specify the PFB forward velocity. The paper demonstrates that the textile material constitutive equations and the MBS algorithms can be used effectively to obtain numerical solutions that define the state of strain of the textile material and the relative slip between rollers and PFB and therefore provide a good method to study the roll-drafting process in the chemical textile industry.
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Goyal, Sachin. "Modeling Thermal Fluctuations of Bio-Filaments With Elastic Rod Theory". In ASME 2013 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/detc2013-13457.
Testo completoAbstract (sommario):
Bio-filaments at sub-micron scales such as DNA perform their biological functions via well-regulated structural deformations that involve large twisting and bending. The strain energies associated with these deformations are of the order of the thermal kinetic energies of surrounding solvent molecules. Therefore, the bio-filaments at such small length scales also exhibit large fluctuations in their shape due to the random collisions of the solvent molecules with them. These thermal fluctuations may, on one hand, help the bio-filaments explore functionally desirable configuration space, while, on the other hand, hinder the regulation of their deformations by motor proteins. Nevertheless, it seems indispensable to model the thermal fluctuations to accurately study the dynamics of deformation of bio-filaments. This paper presents the first elastic rod formulation that incorporates the thermal fluctuations by modeling the impacts of solvent molecules as distributed stochastic force. For quasi-static fluctuations, this formulation leverages the simplicity of a rod formulation noted by Anker et al. [1] that allows solving it as an initial value problem (IVP) in single iteration, and yet capturing arbitrarily large (nonlinear) deformations with rigorous description of constitutive laws.
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Ali, Muhammad, e Isaiah Yasko. "Experimental Study of Composite Prepreg Layup and Fused Filament Fabricated Hydrodynamic Thrust Bearings". In ASME 2024 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2024. https://doi.org/10.1115/imece2024-144728.
Testo completoAbstract (sommario):
Abstract This research experimentally investigates the operating performance of composite hydrodynamic thrust bearings manufactured using prepreg layup and three-dimensional fused filament fabrication methods. Literature on the specific composite formulations being experimentally tested as hydrodynamic thrust bearing stock material in this study is not publicly available. Experimental analysis was conducted on a traditional aluminum-based, bisphenol resin and carbon fiber prepreg layup, and a three-dimensional fused filament fabricated chopped carbon fiber filled nylon hydrodynamic tapered-land thrust bearing. Each bearing was subjected to specific loads and sliding speeds ranging from 0.18–0.72 MPa and 4.11–8.23 m/s, respectively. Oil type and temperature was held constant throughout the analysis. Film pressure distribution, film thickness, and the change in bearing temperature due to frictional heating were recorded for each test. Results show that both composite bearings operated with improved performance when compared to a standard aluminum bearing. The composite layup bearing operated with pressures, minimum films, and bearing temperature elevations 43% higher, 30.5% thicker, and 25% lower than the aluminum bearing, respectively. The composite fused filament fabricated bearing operated with pressures, minimum films, and bearing temperature elevations 254% higher, 113% thicker, and 34% lower than the aluminum bearing, respectively. The results presented here provide justification for further research and potential deployment of composite layup and FFF materials in the hydrodynamic thrust bearing industry.