Investigation of the Correlation Between Micro-Scale Particle Distribution in 3D Printing and Macroscopic Composite Performance

2017 ◽  
Author(s):  
Lu Lu ◽  
Erina Baynojir Joyee ◽  
Yayue Pan
Keyword(s):  
Magnetic Field ◽  
Particle Distribution ◽  
Distribution Patterns ◽  
Physical Models ◽  
Distribution Data ◽  
Material Distribution ◽  
Polymer Liquid ◽  
Micro Scale ◽  
Scale Particle ◽  
Manufacturing Technologies

To date, various multi-material and multi-functional Additive Manufacturing technologies have been developed for the production of multi-functional smart structures. Those technologies are capable of controlling the local distributions of materials, hence achieving gradient or heterogeneous properties and functions. Such multi-material and multi-functional manufacturing capability opens up new applications in many fields. However, it is still largely unknown that how to design the localized material distribution to achieve the desired product properties and functionalities. To address this challenge, the correlation between the micro-scale material distribution and the macroscopic composite performance needs to be established. In our previous work, a novel Magnetic-field-assisted Stereolithography (M-PSL) process has been developed, for fabricating magnetic particle-polymer composites. Hence, in this work, we focus on the study of magnetic-field-responsive particle-polymer composite design, with the aim of developing some guidelines for predicting the magnetic-field-responsive properties of the composite fabricated by M-PSL process. Micro-scale particle distribution parameters, including particle loading fraction, particle magnetization, and distribution patterns, are investigated. Their influences on the properties of particle-polymer liquid suspensions, and the properties of the 3D printed composites, are characterized. By utilizing the magnetic anisotropy properties of the printed composites, different motions of the printed parts could be triggered at different relative positions under the applied magnetic field. Physical models are established, to predict the particle-polymer liquid suspension properties and the trigger conditions of fabricated parts. Experiments are performed to verify the physical models. The predicted results agree well with the experimental measurements, indicating the effectiveness of predicting the macroscopic composite performance using micro-scale distribution data, and the feasibility of using the physical models for guiding the multi-material and multi-functional composite design.

Correlation Between Microscale Magnetic Particle Distribution and Magnetic-Field-Responsive Performance of Three-Dimensional Printed Composites

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Lu Lu ◽  
Erina Baynojir Joyee ◽  
Yayue Pan
Keyword(s):  
Magnetic Field ◽  
Polymer Composites ◽  
Magnetic Particle ◽  
Particle Distribution ◽  
Three Dimensional ◽  
Distribution Patterns ◽  
Chain Structure ◽  
Physical Models ◽  
Distribution Data ◽  
Material Distribution

To date, several additive manufacturing (AM) technologies have been developed for fabricating smart particle–polymer composites. Those techniques can control particle distributions to achieve gradient or heterogeneous properties and functions. Such manufacturing capability opened up new applications in many fields. However, it is still widely unknown how to design the localized material distribution to achieve desired product properties and functionalities. The correlation between microscale material distribution and macroscopic composite performance needs to be established. In our previous work, a novel magnetic field-assisted stereolithography (M-PSL) process was developed, for fabricating magnetic particle–polymer composites. In this work, we focused on the study of magnetic-field-responsive particle–polymer composite design with the aim of developing guidelines for predicting the magnetic-field-responsive properties of the composite. Microscale particle distribution parameters, including particle loading fraction, magnetic particle chain structure, microstructure orientation, and particle distribution patterns, were investigated. Their influences on the properties of particle–polymer liquid suspensions and properties of the three-dimensional (3D) printed composites were characterized. By utilizing the magnetic anisotropy properties of the printed composites, motions of the printed parts could be actuated at different positions in the applied magnetic field. Physical models were established to predict magnetic properties of the composite and trigger distance of fabricated parts. The predicted results agreed well with the experimental measurements, indicating the effectiveness of predicting macroscopic composite performance using microscale distribution data, and the feasibility of using the developed physical models to guide multimaterial and multifunctional composite design.

Molecular Dynamics in Simulation of Magneto-Rheological Fluids Behavior

2013 ◽  
Vol 542 ◽  
pp. 11-27 ◽  
Author(s):  
Marek Barski ◽  
Małgorzata Chwał ◽  
Piotr Kędziora
Keyword(s):  
Magnetic Field ◽  
Molecular Dynamics ◽  
Molecular Dynamic ◽  
Particle Distribution ◽  
Computational Simulations ◽  
Dynamic Algorithm ◽  
Micro Scale ◽  
Macro Scale ◽  
Magneto Rheological ◽  
Ferromagnetic Particles

The present paper is devoted to computational simulations of magneto - rheological fluids behavior subjected to external magnetic fields. In order to perform these simulations the modified molecular dynamic algorithm is adopted. The theoretical model of the magneto - rheological fluid in micro scale as well as the basic interactions between the ferromagnetic particles are discussed. Moreover, the classical molecular dynamic algorithm and its necessary modifications are also described. The proposed approach makes possible to study the process of the internal structure (constructed from the ferromagnetic particles) formation under external magnetic field. The obtained results in the form of the particle distribution in the representative volume can be further used in order to evaluate the mechanical or physical properties of the fluid in macro scale, for example magnetic permeability, heat conduction, etc.

Orientation of a longitudinal polymer liquid crystal in a constant magnetic field

Polymer ◽  
1999 ◽  
Vol 40 (6) ◽  
pp. 1441-1449 ◽  
Author(s):  
Witold Brostow ◽  
Elena A. Faitelson ◽  
Mihail G. Kamensky ◽  
Vadim P. Korkhov ◽  
Yuriy P. Rodin
Keyword(s):  
Magnetic Field ◽  
Liquid Crystal ◽  
Constant Magnetic Field ◽  
Polymer Liquid ◽  
Polymer Liquid Crystal

scholarly journals Preventive maintenance pada mesin die casting dengan age replacement model untuk peningkatan reliabilitas mesin

2020 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Andriani Andriani ◽  
Ikhsan Romli
Keyword(s):  
Preventive Maintenance ◽  
Die Casting ◽  
Casting Machine ◽  
Engine Performance ◽  
Cost Savings ◽  
Distribution Patterns ◽  
Distribution Data ◽  
Time Data ◽  
Replacement Model ◽  
Age Replacement

In an industry, the maintenance department plays a very important role in ensuring the smooth production process. The method of machine maintenance with preventive maintenance is a strategy that can be used to repair existing machines. This is related to proper and regular maintenance can improve engine performance and reduce the level of engine damage which will increase the continuity of production activities. In the die casting division of PT Astra Honda Motor in the observation on the die casting machine 07 there were 45 times damage to the ladle component and 11 times the damage to the auto spray component. These two components are critical components of the 07 die casting machine. After testing the compatibility index and the good compatibility of the damage time data and repair time data to obtain distribution data distribution patterns, obtain the tablespoon component MTTF assessment results of 107,833 hours and auto spray components amounting to 314,226 hours. Whereas the MTTR value of the spoon component is 0.385 hours and the auto spray component is 0.766 hours. The next step is to look for critical component replacement time intervals with the age replacement model, to further review whether it is related to increased reliability, decrease in total downtime, and cost savings before preventive maintenance is carried out and after preventive maintenance is carried out.

scholarly journals Distribution patterns and conservation status of Crocus species in Iran, one of the diversity centers of Crocus in the Middle East

2021 ◽  
Vol 48 (2) ◽  
pp. 156-168
Author(s):  
Melika Tabasi ◽  
Ahmadreza Mehrabian ◽  
Sadaf Sayadi
Keyword(s):  
Middle East ◽  
Conservation Status ◽  
Distribution Patterns ◽  
Field Studies ◽  
Distribution Data ◽  
Herbarium Specimens ◽  
Distribution Centers ◽  
Boundary Area ◽  
Universal Transverse Mercator ◽  
Western Asia

Abstract Assessing distribution patterns of valuable taxa plays an important role in the biodiversity conservation of these taxa. The genus Crocus L. (Iridaceae) comprises about 100 species that are distributed mainly in the Mediterranean region and western Asia. The present study purposed to assess the distribution patterns of Iranian Crocus species (including C. sativus L. and 8 wild species) and their conservation status in Iran as one of diversity centers of Crocus in the Middle East. A set of geographic distribution data was compiled through field studies, and reviews of herbarium specimens, iNaturalist, and various Flora. Localities were marked on geo-referenced maps (1/106) of Iran using ArcView version 3.2 (Esri, 2000). The distribution patterns of the taxa were mapped per 0.25° × 0.25° universal transverse Mercator grid cells (25 km2 with the exception of boundary area). Based on the species distribution (SDI) (33%) and species specialization (SSI) (44%) indices, those Iranian Crocus species that are threatened are mainly distributed in Irano-Turanian region. The mountainous ecosystems of Almeh and Western Alborz are important distribution centers of these taxa. Iranian Crocus species with SSI < 0.5 (C. almehensis, C. gilanicus, C. michelsonii, and C. caspius) have the highest conservation value.

Physical and Fuzzy Logic Modeling of a Flip-Chip Thermocompression Bonding Process

1993 ◽  
Vol 115 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Sa-Yoon Kang ◽  
H. Xie ◽  
Y. C. Lee
Keyword(s):  
Fuzzy Logic ◽  
Flip Chip ◽  
Low Cost ◽  
Distribution Patterns ◽  
Logic Model ◽  
Physical Models ◽  
High Yield ◽  
Yield Model ◽  
Physical Yield ◽  
Fuzzy Logic Model

Flip-Chip connections using gold-to-gold, gold-to-aluminum, or gold-to-solder bondings or contacts enhanced by epoxy are low-cost alternatives to soldering. To assist their technology advancements, we have developed yield models for a representative assembly process with flip-chip, thermocompression bondings. Based on bonding mechanics, a physical yield model has been developed to characterize the process. Then, a fuzzy logic model has been established to improve the modeling’s accuracy by including experimental data. The physical yield model can predict the assembly yield as a function of forces and planarities of the end effector, bump height variations, bump geometries, mechanical properties corresponding to different materials and temperatures, and distribution patterns of bumps. Consistent with our experimental experience, the calculated force level for a high-yield process was around 3000 gmf for a 30-gold-bump chip with a bump diameter of 60 μm and a height of 50 μm. The fuzzy logic model can be trained and adjusted by the results of physical models and experiments. It correlates very well to the nonlinear relationships between the yield and the assembly parameters, and has a self-learning capability to update itself with new data. Such capabilities have been demonstrated by studying the bonding on a substrate with or without a compliant layer.

Micro-scale tearing mode turbulence in the diffusion region during macro-scale evolution of turbulent reconnection

2021 ◽  
Author(s):  
Takuma Nakamura ◽  
Hiroshi Hasegawa ◽  
Tai Phan ◽  
Kevin Genestreti ◽  
Richard Denton ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energy Conversion ◽  
Magnetic Reconnection ◽  
Diffusion Region ◽  
Electron Diffusion ◽  
Efficient Energy ◽  
Micro Scale ◽  
Island Evolution ◽  
Macro Scale ◽  
Scale Evolution

&lt;p&gt;Magnetic reconnection is a key fundamental process in collisionless plasmas that explosively converts magnetic energy to plasma kinetic and thermal energies through a change of magnetic field topology in an electron-scale central region called the electron diffusion region. Past simulations and observations demonstrated that this process causes efficient energy conversion through the formation of multiple macro-scale or micro-scale magnetic islands/flux ropes. However, how these different spatiotemporal scale phenomena are coupled is still poorly understood. In this study, to investigate the turbulent evolution of magnetic reconnection, we perform a new large-scale fully kinetic simulation of a thin current sheet considering a power-law spectrum of initial fluctuations in the magnetic field as frequently observed in the Earth&amp;#8217;s magnetotail. The simulation demonstrates that during a macro-scale evolution of turbulent reconnection, the merging of macro-scale islands results in reduction of the rate of reconnection as well as the aspect ratio of the electron diffusion region. This allows the repeated, quick formation of new electron-scale islands within the electron diffusion region, leading to an efficient energy cascade between macro- and micro-scales. The simulation also demonstrates that a strong electron acceleration/heating occurs during the micro-scale island evolution within the EDR. These new findings indicate the importance of non-steady features of the EDR to comprehensively understand the energy conversion and cascade processes in collisionless reconnection.&lt;/p&gt;

scholarly journals In situ observations show vertical community structure of pelagic fauna in the eastern tropical North Atlantic off Cape Verde

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
H. J. T. Hoving ◽  
P. Neitzel ◽  
H. Hauss ◽  
S. Christiansen ◽  
R. Kiko ◽  
...  
Keyword(s):  
Climate Change ◽  
North Atlantic ◽  
Global Climate ◽  
Distribution Patterns ◽  
Cape Verde ◽  
Distribution Data ◽  
Low Oxygen ◽  
Study Region ◽  
Tropical North Atlantic ◽  
Minimum Zone

AbstractDistribution patterns of fragile gelatinous fauna in the open ocean remain scarcely documented. Using epi-and mesopelagic video transects in the eastern tropical North Atlantic, which features a mild but intensifying midwater oxygen minimum zone (OMZ), we established one of the first regional observations of diversity and abundance of large gelatinous zooplankton. We quantified the day and night vertical distribution of 46 taxa in relation to environmental conditions. While distribution may be driven by multiple factors, abundance peaks of individual taxa were observed in the OMZ core, both above and below the OMZ, only above, or only below the OMZ whereas some taxa did not have an obvious distribution pattern. In the eastern eropical North Atlantic, OMZ expansion in the course of global climate change may detrimentally impact taxa that avoid low oxygen concentrations (Beroe, doliolids), but favour taxa that occur in the OMZ (Lilyopsis, phaeodarians, Cydippida, Colobonema, Haliscera conica and Halitrephes) as their habitat volume might increase. While future efforts need to focus on physiology and taxonomy of pelagic fauna in the study region, our study presents biodiversity and distribution data for the regional epi- and mesopelagic zones of Cape Verde providing a regional baseline to monitor how climate change may impact the largest habitat on the planet, the deep pelagic realm.

scholarly journals Effects of Filler Distribution on Magnetorheological Silicon-Based Composites

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3017 ◽  
Author(s):  
Sneha Samal ◽  
Marcela Škodová ◽  
Ignazio Blanco
Keyword(s):  
Magnetic Field ◽  
Surface Morphology ◽  
Smart Materials ◽  
Particle Distribution ◽  
Volume Fraction ◽  
Filler Particle ◽  
Iron Particles ◽  
Magnetorheological Elastomer ◽  
Linear Arrangement ◽  
Filler Distribution

The smart materials subclass of magnetorheological elastomer (MRE) composites is presented in this work, which aimed to investigate the influence of filler distribution on surface morphology. Iron particles with sizes ranging from 20 to 150 µm were incorporated into the elastomer matrix and a 30% volume fraction (V%) was chosen as the optimal quantity for the filler amount in the elastomer composite. The surface morphology of MRE composites was examined by 3D micro-computed tomography (µCT) and scanning electron microscopy (SEM) techniques. Isotropic and anisotropic distributions of the iron particles were estimated in the magnetorheological elastomer composites. The filler particle distribution at various heights of the MRE composites was examined. The isotropic distribution of filler particles was observed without any influence from the magnetic field during sample preparation. The anisotropic arrangement of iron fillers within the MRE composites was observed in the presence of a magnetic field during fabrication. It was shown that the linear arrangement of the iron particle chain induced magnetization within the composite. Simulation analysis was also performed to predict the particle distribution of magnetization in the MREs and make a comparison with the experimental observations.

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