Journal articles: 'Digimat'

1

Trzepieciński, Tomasz, Grażyna Ryzińska, Mojtaba Biglar, and Magdalena Gromada. "Modelling of multilayer actuator layers by homogenisation technique using Digimat software." Ceramics International 43, no. 3 (February 2017): 3259–66. http://dx.doi.org/10.1016/j.ceramint.2016.11.157.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Khammassi, Sabrine, and Mostapha Tarfaoui. "Influence of exfoliated graphite filler size on the electrical, thermal, and mechanical polymer properties." Journal of Composite Materials 54, no. 25 (April 16, 2020): 3731–41. http://dx.doi.org/10.1177/0021998320918639.

Full text

Abstract:

Exfoliated graphite has attracted significant research interest, especially with respect to composite manufacturing as a sheet shape material for enhancing their mechanical, electrical, and thermal properties with cost-effectiveness. It has been proved in different researches that size of nanoparticles plays a vital role and has significant effect. So, in this study, exfoliated graphite with three different sizes i.e. 50 mesh (large dimension), 100 mesh (medium size), and 150 mesh (small size) are integrated in epoxy to examine their effect on the mechanical/electrical/thermal performance of the material and for each mesh size range of 0.5 wt.% to 20 wt.% is utilized. These three systems of reinforced epoxy with different size of exfoliated graphite are evaluated in DIGIMAT simulation software by investigating their electrical, thermal and mechanical properties. The numerical results showed that integration of exfoliated graphite in neat epoxy drastically improved its electrical, thermal, and mechanical performance. In addition, it was found that the use of the bigger size was more effective on the performance of the material, which is probably because of the enhanced connectivity between the structuring sheets. Moreover, a gradual increase in properties is observed with increasing the percentage of exfoliated graphite content in each system. This numerical study was developed in accordance to validate the experimental study conducted by Debelak et al. This study further provides the evidence of the appropriateness of the DIGIMAT simulation as an investigational load in relevant research.

APA, Harvard, Vancouver, ISO, and other styles

3

Kim, Young-Man, and Yong-Hwan Kim. "Coupled Analysis with Digimat for Realizing the Mechanical Behavior of Glass Fiber Reinforced Plastics." Journal of the Computational Structural Engineering Institute of Korea 32, no. 6 (December 31, 2019): 349–57. http://dx.doi.org/10.7734/coseik.2019.32.6.349.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Pan, Qinxue, Shuangyang Li, Yang Liu, Xiaoyu Xu, Meile Chang, and Yunmiao Zhang. "Meso-Simulation and Experimental Research on the Mechanical Behavior of an Energetic Explosive." Coatings 11, no. 1 (January 7, 2021): 64. http://dx.doi.org/10.3390/coatings11010064.

Full text

Abstract:

This study establishes a model for polymer-bonded explosives (PBX) using Digimat-FE. The model identifies the relationship between the material’s effective elastic modulus and the explosive particle volume fraction, shape and gradation, and porosity, as well as other factors. Further, finite element analysis of the stress distribution of the PBX composite material is performed, and the mathematical models between the ultrasonic attenuation coefficient, particle volume fraction, and ultrasonic frequency are established. Finally, an efficient ultrasonic nondestructive testing system is designed to determine the stress distribution and fine crack groups in the material. Experimental results indicate that the relative error of stress detection is within 15%, which meets the requirements of engineering applications.

APA, Harvard, Vancouver, ISO, and other styles

5

Pan, Qinxue, Shuangyang Li, Yang Liu, Xiaoyu Xu, Meile Chang, and Yunmiao Zhang. "Meso-Simulation and Experimental Research on the Mechanical Behavior of an Energetic Explosive." Coatings 11, no. 1 (January 7, 2021): 64. http://dx.doi.org/10.3390/coatings11010064.

Full text

Abstract:

This study establishes a model for polymer-bonded explosives (PBX) using Digimat-FE. The model identifies the relationship between the material’s effective elastic modulus and the explosive particle volume fraction, shape and gradation, and porosity, as well as other factors. Further, finite element analysis of the stress distribution of the PBX composite material is performed, and the mathematical models between the ultrasonic attenuation coefficient, particle volume fraction, and ultrasonic frequency are established. Finally, an efficient ultrasonic nondestructive testing system is designed to determine the stress distribution and fine crack groups in the material. Experimental results indicate that the relative error of stress detection is within 15%, which meets the requirements of engineering applications.

APA, Harvard, Vancouver, ISO, and other styles

6

Kaptakov, M. O. "Modelling of Mechanical Properties of Metal Plates with Polymer Coatings." Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, no. 5 (April 11, 2021): 530–34. http://dx.doi.org/10.17762/turcomat.v12i5.1048.

Full text

Abstract:

In this work, we compare the experimental and calculated results obtained in the numerical simulation of uniaxial tension of specimens of metal plates with a thickness of 0.7 mm. For modeling, the Digimat-FE (MSC) system was used, which in numerical calculations uses the finite element solver of the Marc software package (MSC). It is shown that for samples without coatings, the found theoretical values of the critical load quite well correspond to the points on the experimental diagrams at which the dependence of the load and displacement ceases to be linear. For specimens with coatings, the critical loads are significantly lower, and for their description it is necessary to obtain a refined estimate taking into account the effect of residual stresses.

APA, Harvard, Vancouver, ISO, and other styles

7

Nayak, Biswajeet, and R. K. Sahu. "Experimental and Digimat-FE based representative volume element analysis of exceptional graphene flakes/aluminium alloy nanocomposite characteristics." Materials Research Express 6, no. 11 (October 18, 2019): 116593. http://dx.doi.org/10.1088/2053-1591/ab4bb7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Kurkin, Evgenii Igorevich, and Mariia Olegovna Spirina. "Processing the Results of Measuring the Mechanical Characteristics of Plated Specimens." Key Engineering Materials 834 (March 2020): 90–97. http://dx.doi.org/10.4028/www.scientific.net/kem.834.90.

Full text

Abstract:

Paper is devoted to the automation of processing the results of measurements of mechanical characteristics of plated specimens and the creation of a mathematical model of anisotropy material. Methods of conducting tensile and flexural tests are described. Developed in MATLAB tools for automation of processing results of experiments are proposed. Tools can be used for interpretation of the results of strength tests of isotropic and composite materials. The advantage of the developed tools is batch processing, which allows processing the results of a large series of experiments. The tools system was tested when creating a model of short-reinforced composite material. An example of the use of test results when constructing the Digimat material model and using this model to predict the stress-strain state of anisotropic structures is presented.

APA, Harvard, Vancouver, ISO, and other styles

9

Kalteis, Anna, Martin Reiter, Michael Jerabek, and Zoltán Major. "VALIDATION AND IMPLEMENTATION OF FAILURE PARAMETERS IN INTEGRATED SIMULATIONS FOR SHORT FIBRE REINFORCED POLYPROPYLENE." Acta Polytechnica CTU Proceedings 7 (December 9, 2016): 22. http://dx.doi.org/10.14311/app.2017.7.0022.

Full text

Abstract:

Nowadays short fibre reinforced polymers are often used in load carrying structural parts. Compared to continuous fibre reinforced polymers they exhibit a more complex morphology. Hence the determination of the strength is a difficult but important task. Therefore this was the objective of this research. The strength of short fibre reinforced polymers was numerically determined for low-speed to high-speed strain rates for specimens with different fibre orientations. For the failure modelling the micromechanical approach “First pseudo grain failure” in Digimat was used. The parameters for the material and failure description were determined with the reverse engineering method. Integrated finite element simulations<br />were performed to validate the material and failure models by tensile and bending tests with different specimens. The comparison of the results of the experiments and simulations showed low deviation.

APA, Harvard, Vancouver, ISO, and other styles

10

Nyanor, Peter, Omayma A. El Kady, Atef S. Hamada, Koichi Nakamura, and Mohsen A. Hassan. "Multiscale Finite Element Simulation of Thermal Properties and Mechanical Strength of Reduced Graphene Oxide Reinforced Aluminium Matrix Composite." Key Engineering Materials 821 (September 2019): 39–46. http://dx.doi.org/10.4028/www.scientific.net/kem.821.39.

Full text

Abstract:

The effective properties of metal matrix composites (MMCs) depend on matrix material and reinforcement property specifications as well as bonding at interphase. The use of numerical methods such as finite element (FE) and mean field homogenization (MFH) can assist in predicting MMC properties thus reducing time and cost of optimizing composite properties through experiments. In the present work, a multiscale representative volume element (RVE) of the microstructure of reduced graphene oxide (rGO) reinforced Aluminium (Al) matrix composite (rGO/Al) is created in MSC DigiMat and analysed using Abaqus software. The effect of porosity and rGO reinforcement on thermal conductivity and strength of the rGO/Al composites is studied. The variation in thermal conductivity between FE-RVE and experimental data is a maximum of 2.2% and a minimum of 0.07% for rGO reinforcement of 1 wt.% and 3 wt.% respectively. The results show good agreement between FE-RVE simulation, MFH and experimental data. This approach can provide an efficient technique for selecting matrix and reinforcement phase properties for MMC fabrication. Keywords: Al/rGO composite, Multiscale finite element-representative volume, Thermal and mechanical properties

APA, Harvard, Vancouver, ISO, and other styles

11

Das Lala, Sumit, Shaik Sadikbasha, and Ashish B. Deoghare. "Prediction of elastic modulus of polymer composites using Hashin–Shtrikman bound, mean field homogenization and finite element technique." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 234, no. 8 (December 23, 2019): 1653–59. http://dx.doi.org/10.1177/0954406219895791.

Full text

Abstract:

Polymer matrix composites are developed by reinforcing biodegradable rubber seed shell, cashew nut shell and walnut shell powder in epoxy resin. Theoretically, elastic modulus is calculated using Hashin–Shtrikman bounds using variational principles. Investigation of the elastic modulus of the composites is extended by varying filler weight up to 25% in Digimat 2017-MF which applies Mori–Tanaka mean field homogenization and ANSYS 15.0 Workbench which uses a three-dimensional model of representative volume element having spherical shaped filler particles to calculate elastic modulus. Elastic modulus is the measurement of resistance of the material under tensile load. The corresponding stress–strain relationship predicts the stiffness of the material. The results are confirmed with experimentation approach for 5% wt filler content. Elastic modulus obtained from these approaches show a maximum error of 7% with experiment results. Investigation further reveals that elastic modulus of composites increases with increase in weight fraction of fillers. However, above 15% wt of filler content, no significant increase in the elastic modulus of the composites is observed.

APA, Harvard, Vancouver, ISO, and other styles

12

Miedzińska, Danuta, Robert Panowicz, and Przemysław Jóźwicki. "Multiscale Modelling Method for Chosen Functionally Graded Material." Solid State Phenomena 199 (March 2013): 593–98. http://dx.doi.org/10.4028/www.scientific.net/ssp.199.593.

Full text

Abstract:

The paper deals with the numerical and experimental analyses of functionally graded material structures which are represented by a surface layer of the steel sample hardened during the laser treatment process. A functionally graded parameter of the researched structure was assumed as the hardness value experimentally measured with the use of a Vickers hardness test method. The microstructure of the tested layer was also analyzed for the Vickers test verification. Two homogenization methods were used for the purpose of layer substitute properties for numerical calculations. The first one was to divide the FGM domain into a number of layers in the direction of material gradation and then apply a numerical homogenization method within each layer. The resulting material model describes the FGM as a composite of homogeneous layers. The second method was based on the Mori-Tanaka homogenization theory and was carried out with the use of Digimat software, which is the nonlinear multi-scale materials and structures modelling platform. Both methods were compared and showed good correspondence.

APA, Harvard, Vancouver, ISO, and other styles

13

Li, Fei, Jingyu Sun, Hualong Xie, Kun Yang, and Xiaofei Zhao. "Thermal Deformation of PA66/Carbon Powder Composite Made with Fused Deposition Modeling." Materials 13, no. 3 (January 22, 2020): 519. http://dx.doi.org/10.3390/ma13030519.

Full text

Abstract:

Polyamide 66 (PA66) is a material with high wear resistance, toughness, and heat resistance. However, low stiffness and thermal deformation during thermal processes define applications in many conditions. Carbon powder efficiently enhances stiffness and reduces thermal deformation, which makes up defects of plastic materials. However, forming a composite with fused deposition modeling (FDM) that accumulates material to a specified location by melting plastic filaments is limited, including fluidity and viscosity to form normally. In this paper, filaments of polyamide 66 (PA66) reinforced with carbon powder were produced. Digimat was used to analyze the composite material properties of different carbon contents and predict the proper carbon content. Then, the material properties were imported to ANSYS software to simulate the thermal deformation of the workpieces during processing. It was verified that adding carbon powder is helpful in decreasing thermal deformation. Comparing experiments and simulations, we found that 20% carbon mass fraction was best, and that thermal deformation was minimal at 240 °C nozzle temperature while hot bed temperature was 90 °C. The optimal ratio of extrusion speed to filling speed was 0.87, and the best aspect ratio was 0.25.

APA, Harvard, Vancouver, ISO, and other styles

14

Tserpes, Konstantinos, Vasileios Tzatzadakis, and Jens Bachmann. "Electrical Conductivity and Electromagnetic Shielding Effectiveness of Bio-Composites." Journal of Composites Science 4, no. 1 (March 18, 2020): 28. http://dx.doi.org/10.3390/jcs4010028.

Full text

Abstract:

In this paper, the electrical conductivity and electromagnetic shielding effectiveness of two bio-composites are studied by experimental testing and numerical models. Two monolithic composites with partly bio-based content were manufactured. The first bio-composite is made of a carbon fiber fabric prepreg and a partly bio-based (rosin) epoxy resin (CF/Rosin). The second bio-composite is a combination of prepregs of carbon fiber fabric/epoxy resin and flax fiber fabric/epoxy resin (CF-Flax/Epoxy). A single line infusion process was used prior to the curing step in the autoclave. Both variants are exemplary for the possibility of introducing bio-based materials in high performance CFRP. In-plane and out-of-plane electrical conductivity tests were conducted according to Airbus standards AITM2 0064 and AITM2 0065, respectively. Electromagnetic shielding effectiveness tests were conducted based on the standard ASTM D 4935-10. Materials were prepared at the German Aerospace Center (DLR), while characterization tests were conducted at the University of Patras. In addition to the tests, numerical models of representative volume elements were developed, using the DIGIMAT software, to predict the electrical conductivity of the two bio-composites. The preliminary numerical results show a good agreement with the experimental results.

APA, Harvard, Vancouver, ISO, and other styles

15

Rouway, Marwane, Mourad Nachtane, Mostapha Tarfaoui, Nabil Chakhchaoui, Lhaj El Hachemi Omari, Fouzia Fraija, and Omar Cherkaoui. "Mechanical Properties of a Biocomposite Based on Carbon Nanotube and Graphene Nanoplatelet Reinforced Polymers: Analytical and Numerical Study." Journal of Composites Science 5, no. 9 (September 3, 2021): 234. http://dx.doi.org/10.3390/jcs5090234.

Full text

Abstract:

Biocomposites based on thermoplastic polymers and natural fibers have recently been used in wind turbine blades, to replace non-biodegradable materials. In addition, carbon nanofillers, including carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs), are being implemented to enhance the mechanical performance of composites. In this work, the Mori–Tanaka approach is used for homogenization of a polymer matrix reinforced by CNT and GNP nanofillers for the first homogenization, and then, for the second homogenization, the effective matrix was used with alfa and E-glass isotropic fibers. The objective is to study the influence of the volume fraction Vf and aspect ratio AR of nanofillers on the elastic properties of the composite. The inclusions are considered in a unidirectional and random orientation by using a computational method by Digimat-MF/FE and analytical approaches by Chamis, Hashin–Rosen and Halpin–Tsai. The results show that CNT- and GNP-reinforced nanocomposites have better performance than those without reinforcement. Additionally, by increasing the volume fraction and aspect ratio of nanofillers, Young’s modulus E increases and Poisson’s ratio ν decreases. In addition, the composites have enhanced mechanical characteristics in the longitudinal orientation for CNT- reinforced polymer and in the transversal orientation for GNP-reinforced polymer.

APA, Harvard, Vancouver, ISO, and other styles

16

Starace, F., SD Orlando, M. Guida, and F. Marulo. "Experimental study of a virtual allowables approach for the design of composite aircraft structures." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 235, no. 14 (July 2021): 2529–41. http://dx.doi.org/10.1177/0954406220987862.

Full text

Abstract:

Statistically derived allowables are representative for the behavior of a composite material system in a given structural context where data variability needs to be contemplated. In particular, they define the strength of the material as characterized by various coupon tests according to ASTM standard procedure subjected to the actual manufacturing process and layup stacking sequences. The current paper presents a detailed comparison between virtual allowables predictions obtained using MSC Digimat and the experimentally determined values of a certified material backed up by a 3x2x3 (batch/panel/specimen) stochastic approach. Tests generate the required data for building material model ab initio of carbon fibers reinforced epoxide resin in form of 2x2 twill woven fabric used for qualifying an innovative composite wing for the Next Generation Tilt Rotor (NGCTR). Numerical models of in-plane tension, compression and shear test methods have been assembled along with an associated material model allowing numerical predictions to be validated with the coupon level experimental results as final purpose. Standard statistical model has been adopted in order to include material and manufacturing process variabilities to define B-basis allowables. The calibrated statistical FEM method performed for different layup configurations have been used to fully characterize the mechanical behavior of the analyzed CFRP material and to predict performances for thicker laminates.

APA, Harvard, Vancouver, ISO, and other styles

17

Romano, Maria Grazia, Michele Guida, Francesco Marulo, Michela Giugliano Auricchio, and Salvatore Russo. "Characterization of Adhesives Bonding in Aircraft Structures." Materials 13, no. 21 (October 28, 2020): 4816. http://dx.doi.org/10.3390/ma13214816.

Full text

Abstract:

Structural adhesives play an important role in aerospace manufacturing, since they provide fewer points of stress concentration compared to faster joints. The importance of adhesives in aerospace is increasing significantly because composites are being adopted to reduce weight and manufacturing costs. Furthermore, adhesive joints are also studied to determine the crashworthiness of airframe structure, where the main task for the adhesive is not to dissipate the impact energy, but to keep joint integrity so that the impact energy can be consumed by plastic work. Starting from an extensive campaign of experimental tests, a finite element model and a methodology are implemented to develop an accurate adhesive model in a single lap shear configuration. A single lap joint finite element model is built by MSC Apex, defining two specimens of composite material connected to each other by means of an adhesive; by the Digimat multi-scale modeling solution, the composite material is treated; and finally, by MSC’s Marc, the adhesive material is characterized as a cohesive applying the Cohesive Zone Modeling theory. The objective was to determine an appropriate methodology to predict interlaminar crack growth in composite laminates, defining the mixed mode traction separation law variability in function of the cohesive energy (Gc), the ratio between the shear strength τ and the tensile strength σ (β1), and the critical opening displacement υc.

APA, Harvard, Vancouver, ISO, and other styles

18

Feng, Yong, Binghui Jia, Xiaoyu Wang, Min Zhang, and Zihao Zhu. "Research on Microscopic Properties of TiBw/TC4 Composites for Drilling Process." Materials 12, no. 13 (June 30, 2019): 2112. http://dx.doi.org/10.3390/ma12132112.

Full text

Abstract:

TiB-whisker-reinforced TiBw/TC4 composites are widely used in aviation, aerospace, automotive, and various other industries. However, the drilling force and temperature have a large effect on the drilling micromechanical properties of TiBw/TC4 composites. In order to explore the micro-mechanical properties and promote the optimization of drilling process, the representative volume elements of TiBW/TC4 composites were established in the Digimat-FE software tool to determine the micromechanical properties and failure mechanism of TiBW/TC4 composites. The results show: (1) maximum stress occurs at the whiskers, whereas the minimum stress appears within the basket matrix region of the reinforced phase. (2) When the force reached 300 N and the temperature reached 75 °C, the junction between the whiskers and the matrix firstly failed; when the force reached 525 N and the temperature reached 112 °C, the matrix began to fail; when the force reached 675 N and the temperature reached 138 °C, the whiskers failed. (3) The main reason for the failure of the junction between the matrix and the whiskers was that the shear stress exceeded the connection strength and the axial stress accelerated the failure process. Displacement and rotation of the whiskers were shown to occur at the moment of junction failure, owing to differences in the stress experienced on different sides of the material.

APA, Harvard, Vancouver, ISO, and other styles

19

Al-Fatlawi, Alaa, Károly Jármai, and György Kovács. "Optimization of a Totally Fiber-Reinforced Plastic Composite Sandwich Construction of Helicopter Floor for Weight Saving, Fuel Saving and Higher Safety." Polymers 13, no. 16 (August 15, 2021): 2735. http://dx.doi.org/10.3390/polym13162735.

Full text

Abstract:

The application of fiber-reinforced plastic (FRP) composites as structural elements of air vehicles provides weight saving, which results in a reduction in fuel consumption, fuel cost, and air pollution, and a higher speed. The goal of this research was to elaborate a new optimization method for a totally FRP composite construction for helicopter floors. During the optimization, 46 different layer combinations of 4 different FRP layers (woven glass fibers with phenolic resin; woven glass fibers with epoxy resin; woven carbon fibers with epoxy resin; hybrid composite) and FRP honeycomb core structural elements were investigated. The face sheets were composed of a different number of layers with cross-ply, angle-ply, and multidirectional fiber orientations. During the optimization, nine design constraints were considered: deflection; face sheet stress (bending load, end loading); stiffness; buckling; core shear stress; skin wrinkling; intracell buckling; and shear crimping. The single-objective weight optimization was solved by applying the Interior Point Algorithm of the Matlab software, the Generalized Reduced Gradient (GRG) Nonlinear Algorithm of the Excel Solver software, and the Laminator software. The Digimat-HC software solved the numerical models for the optimum sandwich plates of helicopter floors. The main contribution is developing a new method for optimizing a totally FRP composite sandwich structure—due to its material constituents and construction—that is more advantageous than traditional helicopter floors. A case study validated this fact.

APA, Harvard, Vancouver, ISO, and other styles

20

Isaincu, Alexandru, Micota Dan, Viorel Ungureanu, and Liviu Marșavina. "Numerical investigation on the influence of fiber orientation mapping procedure to the mechanical response of short-fiber reinforced composites using Moldflow, Digimat and Ansys software." Materials Today: Proceedings 45 (2021): 4304–9. http://dx.doi.org/10.1016/j.matpr.2020.12.792.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Sertse, Hamsasew M., Johnathan Goodsell, Andrew J. Ritchey, R. Byron Pipes, and Wenbin Yu. "Challenge problems for the benchmarking of micromechanics analysis: Level I initial results." Journal of Composite Materials 52, no. 1 (April 3, 2017): 61–80. http://dx.doi.org/10.1177/0021998317702437.

Full text

Abstract:

Because of composite materials’ inherent heterogeneity, the field of micromechanics provides essential tools for understanding and analyzing composite materials and structures. Micromechanics serves two purposes: homogenization or prediction of effective properties and dehomogenization or recovery of local fields in the original heterogeneous microstructure. Many micromechanical tools have been developed and codified, including commercially available software packages that offer micromechanical analyses as stand-alone tools or as part of an analysis chain. With the increasing number of tools available, the practitioner must determine which tool(s) provides the most value for the problem at hand given budget, time, and resource constraints. To date, simple benchmarking examples have been developed in an attempt to address this challenge. The present paper presents the benchmark cases and results from the Micromechanical Simulation Challenge hosted by the Composites Design and Manufacturing HUB. The challenge is a series of comprehensive benchmarking exercises in the field of micromechanics against which such tools can be compared. The Level I challenge problems consist of six microstructure cases, including aligned, continuous fibers in a matrix, with and without an interphase; a cross-ply laminate; spherical inclusions; a plain-weave fabric; and a short-fiber microstructure with “random” fiber orientation. In the present phase of the simulation challenge, the material constitutive relations are restricted to linear thermoelastic. Partial results from DIGIMAT-MF, ESI VPS, MAC/GMC, finite volume direct averaging method, Altair MDS, SwiftComp, and 3D finite element analysis are reported. As the challenge is intended to be ongoing, the full results are hosted and updated online at www.cdmHUB.org .

APA, Harvard, Vancouver, ISO, and other styles

22

BABAYTSEV, Arseniy V., Ye Ko KYAW, Sergey N. VAKHNEEV, and Thant ZIN HEIN. "STUDY OF THE INFLUENCE OF SPHERICAL INCLUSIONS ON MECHANICAL CHARACTERISTICS." Periódico Tchê Química 17, no. 35 (July 20, 2020): 654–62. http://dx.doi.org/10.52571/ptq.v17.n35.2020.56_babaytsev_pgs_654_662.pdf.

Full text

Abstract:

The relevance of the article is due to the stable growth of the composite industry. Due to its high physical and mechanical characteristics, composite materials (CM) play a vital role in many areas of technology, such as aerospace, aviation, automotive, engineering and instrumentation, and the medical industry. When creating materials with the required mechanical and thermal characteristics, various additives and fillers are often used that affect the strength and elasticity of the samples obtained. In this paper, we study the influence of spherical inclusions in epoxy on the mechanical properties of the material. A composite structure of ED-20 epoxy with inclusions in the form of spherical particles of PBS-50 glass was considered. The characteristic particle size was about 50 μm. Within the framework of this study, batches of samples with a specific volumetric inclusion content of 5%, 10%, 15%, and 20% were produced. Each batch consisted of 6 samples of the same type. To check the distribution of particle volume and inclusion studies, the microstructure of the thin section of the sample and separately the powder were studied. Using methods of modeling the process, the samples were tested for 3-point bending. Based on the results of mechanical tests, the elastic module, strength limit, and ultimate strains were obtained. As part of the study of materials, numerical calculations were performed using Digimat software (MSC Software) to model the structure and obtain effective material properties, as well as strength analysis using the finite element method in Ansys Workbench. The calculation was carried out for the volumetric content of inclusions of 5%, 10%, 15%, and 20% order and in the absence of inclusions. The obtained numerical results were compared with an experimental study. Based on the numerical calculations, the dependence of the percentage of inclusions on the strength limit and elastic module was obtained.

APA, Harvard, Vancouver, ISO, and other styles

23

BABAYTSEV, Arseniy V., Ekaterina L. KUZNETSOVA, Lev N. RABINSKIY, and Olga V. TUSHAVINA. "INVESTIGATION OF PERMANENT STRAINS IN NANOMODIFIED COMPOSITES AFTER MOLDING AT ELEVATED TEMPERATURES." Periódico Tchê Química 17, no. 34 (March 20, 2020): 1055–73. http://dx.doi.org/10.52571/ptq.v17.n34.2020.1087_p34_pgs_1055_1073.pdf.

Full text

Abstract:

This work investigates the effect of carbon nanomodification on the residual stress-strain state (SSS) after molding. One of the ways to reduce residual stresses and deformities is nanomodification. The main objective was to determine the degree of influence of the nanomodification parameters on the residual SSS. Within the framework of this study, 4 slabs were made. Two slabs are made of a conventional binder with laying [010/9010] and [010/4510] and two slabs of a modified binding material with the same layer structure. For the fabricated plates, deflections were measured on each of the four sides, during which residual strains were obtained in the panels of nanomodified carbon fiber for the considered layings with and without modified binding material. To analyze the residual stress-strain state, a numerical and analytical calculation was performed. The numerical calculation was carried out by means of the finite element method for the case when the slab is fixed at the point of the geometric center, with no power load, and the temperature load is a difference of 100 °C. An analytical calculation was carried out for the case when the slab is free from fastening and external power load, and the temperature load is a difference of 100°C. During the study, variants of the physicomechanical properties of the monolayer were obtained using the Digimat software and the Mori-Tanaka averaging method. The results obtained by analytical and numerical methods have a good correlation between each other, and in the course of comparison with the experiment, a method for calculating the characteristics of the monolayer that was closest to the experimental result was determined. On the basis of the obtained results, conclusions were made on the possibility of reducing residual SSS and deformation in structures with asymmetric reinforcement schemes using a matrix containing carbon nanoparticles.

APA, Harvard, Vancouver, ISO, and other styles

24

Al-Fatlawi, Alaa, Károly Jármai, and György Kovács. "Optimal Design of a Fiber-Reinforced Plastic Composite Sandwich Structure for the Base Plate of Aircraft Pallets In Order to Reduce Weight." Polymers 13, no. 5 (March 9, 2021): 834. http://dx.doi.org/10.3390/polym13050834.

Full text

Abstract:

The application of fiber-reinforced plastic (FRP) composite materials instead of metals, due to the low density of FRP materials, results in weight savings in the base plates of aircraft pallets. Lower weight leads to lower fuel consumption of the aircraft and thereby less environmental damage. The study aimed to investigate replacing the currently used aluminum base plates of aircraft pallets with composite sandwich plates to reduce the weight of the pallets, thereby the weight of the unit loads transported by aircraft. The newly constructed sandwich base plate consists of an aluminum honeycomb core and FRP composite face-sheets. First, we made experimental tests and numerical calculations for the investigated FRP sandwich panel to validate the applicability of the calculation method. Next, the mechanical properties of 40 different layer-combinations of 4 different FRP face-sheet materials (phenolic woven glass fiber; epoxy woven glass fiber; epoxy woven carbon fiber; and hybrid layers) were investigated using the Digimat-HC modeling program in order to find the appropriate face-sheet construction. Face-sheets were built up in 1, 2, 4, 6 or 8 layers with sets of fiber orientations including cross-ply (0°, 90°) and/or angle-ply (±45°). The weight optimization method was elaborated considering 9 design constraints: stiffness, deflection, skin stress, core shear stress, facing stress, overall buckling, shear crimping, skin wrinkling, and intracell buckling. A case study for the base plate of an aircraft pallet was introduced to validate the optimization procedure carried out using the Matlab (Interior Point Algorithm) and Excel Solver (Generalized Reduced Gradient Nonlinear Algorithm) programs. In the case study, the weight of the optimal structure (epoxy woven carbon fiber face-sheets) was 27 kg, which provides weight savings of 66% compared to the standard aluminum pallet. The article’s main added value is the elaboration and implementation of an optimization method that results in significant weight savings and thus lower fuel consumption of aircraft.

APA, Harvard, Vancouver, ISO, and other styles

25

Lotherington, Heather, and Natalia Sinitskaya Ronda. "Digital Literacies: digilit@york." E-Learning and Digital Media 6, no. 3 (January 1, 2009): 256–58. http://dx.doi.org/10.2304/elea.2009.6.3.256.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Adak, Nitin, and Dr S. D. Lokhande Dr. S. D. Lokhande. "An Accelerometer-Based Digital Pen for Handwritten Digit and Gesture Recognition." Indian Journal of Applied Research 3, no. 12 (October 1, 2011): 207–10. http://dx.doi.org/10.15373/2249555x/dec2013/61.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Aziken, Grace, and Franca Egbokhare. "The Role of Working Memory in Eliciting Users Cognitive Requirements." Advances in Multidisciplinary & Scientific Research Journal Publication 6, no. 4 (December 31, 2018): 57–64. http://dx.doi.org/10.22624/aims/digital/v4n4p62.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Adeyemo, F. S., Mary Daniel, and Aghedo M. "Towards an Assessment of Customer Satisfaction with Nigerian Mobile Telecoms Industry and Providers." Advances in Multidisciplinary & Scientific Research Journal Publication 5, no. 4 (December 31, 2017): 157–61. http://dx.doi.org/10.22624/aims/digital/v5n4px.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Adedibu, O., and M. E. Adeshipo. "A Review of Anomaly Detection Techniques for Intrusion Detection." Advances in Multidisciplinary & Scientific Research Journal Publication 6, no. 4 (December 31, 2018): 1–10. http://dx.doi.org/10.22624/aims/digital/v6n4p1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Edemirukaye, Ukeh Orodje, and T. Simon Apeh. "Evaluation of Automated Metering With Flexible Management and Monitoring System." Advances in Multidisciplinary & Scientific Research Journal Publication 6, no. 4 (December 31, 2018): 11–34. http://dx.doi.org/10.22624/aims/digital/v6n4p2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Danquah (Ph.D), Paul, Benjamin Peh, and Victor Gordon. "A simulated comparison of performance beyond inherent metrics for Open Shortest Path First (OSPF) and Exterior Gateway Routing Protocol (EIGRP)." Advances in Multidisciplinary & Scientific Research Journal Publication 6, no. 4 (December 31, 2018): 35–48. http://dx.doi.org/10.22624/aims/digital/v6n4p3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Taylor, O. E., and O. M. Ata-ebirieng. "A Hybrid Agent-Based Network Monitoring Tool." Advances in Multidisciplinary & Scientific Research Journal Publication 6, no. 4 (December 31, 2018): 49–56. http://dx.doi.org/10.22624/aims/digital/v6n4p4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Aziken, G. O., F. A. Egbokhare, and D. E. Akpon-Ebiyomare. "The Role of Working Memory in Eliciting Users Cognitive Requirements." Advances in Multidisciplinary & Scientific Research Journal Publication 6, no. 4 (December 31, 2018): 57–64. http://dx.doi.org/10.22624/aims/digital/v6n4p6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Adeyemo, O. A., and A. Akinselure. "A Model for Predicting Customer Value Towards Upselling in Medium and Large Scale Businesses (MLBs)." Advances in Multidisciplinary & Scientific Research Journal Publication 7, no. 1 (March 31, 2019): 1–10. http://dx.doi.org/10.22624/aims/digital/v7n1p1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Ikuomola, Aderonke. "Toward a Secured Multi-Step Permission Based Delegation Model with Chinese Wall Security Policy." Advances in Multidisciplinary & Scientific Research Journal Publication 7, no. 1 (January 31, 2019): 11–22. http://dx.doi.org/10.22624/aims/digital/v7n1p2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Ogunrinola, O. B., N. A. Olalere, G. N. Onaifoh, and E. U. Nwosu. "Minimizing the Wastage of Electrical Energy at Utilization Level." Advances in Multidisciplinary & Scientific Research Journal Publication 7, no. 1 (February 6, 2019): 23–32. http://dx.doi.org/10.22624/aims/digital/v7n1p3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Davies, E. I., and V. E. I. Anireh. "Design and Implementation of Smart Home System Using Internet of Things." Advances in Multidisciplinary & Scientific Research Journal Publication 7, no. 1 (March 9, 2019): 33–42. http://dx.doi.org/10.22624/aims/digital/v7n1p4.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Chukwuedo, J. A. "Analysis of Domestic Energy Usage for Electrical Appliances in a Nigerian Metropolitan Area." Advances in Multidisciplinary & Scientific Research Journal Publication 7, no. 1 (March 18, 2019): 43–58. http://dx.doi.org/10.22624/aims/digital/v7n1p5.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Zubair, Abdul Rasak. "Image as a Signal: Review of the Concept of Image Frequency Estimate." Advances in Multidisciplinary & Scientific Research Journal Publication 10, no. 1 (March 31, 2019): 73–86. http://dx.doi.org/10.22624/aims/digital/v7n1p6.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Adelusi, Bamidele Samuel, and Oluwashola David Adeniji. "Analyzing the Usage of Accounting Software for Short Medium Services (SMS) using Panel Data to improve Business competitiveness of Microfinance." Advances in Multidisciplinary & Scientific Research Journal Publication 7, no. 1 (March 31, 2019): 95–110. http://dx.doi.org/10.22624/aims/digital/v7n1p8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Edom, Eunice Uchechi, Remigius Chinedu Onuegbu, and Nkechi G. Leo-Ogbonna. "Factors Influencing Job Satisfaction of Librarians in Federal University Libraries in South-East Geo-Political Zone of Nigeria." advances in multidisciplinary & scientific research journal publication 8, no. 2 (June 30, 2020): 119–28. http://dx.doi.org/10.22624/aims/digital/v8n2p8.

Full text

Abstract:

geo-political zone of Nigeria. Two objectives and research questions respectively were stated to guide the study. Two hypotheses were also tested in the study. The study adopted a correlational design, and the population of the study was 98. Sample of the study was census which involves the use of the entire population. The instrument for data collection was researcher’s structured modified 4-point Likert rating scale. The data collected for the study were analysed using Pearson Product Moment Correlation (PPMC) technique, while the hypotheses were tested for significance statistically using Spearman Rank Correlation analysis at 0.05 level of significance. The findings of the study revealed that there is a significant relationship between staff promotion and job satisfaction of librarians in libraries of federal universities in South-East geopolitical zone of Nigeria. The findings further revealed that there is also significant relationship between staff job security and job satisfaction of librarians in libraries of federal universities in South-East geo-political zone of Nigeria. The study recommended that staff promotion should be done regularly and as at when due to motivate the librarians to work hard in their workplaces. It is also recommended that librarians job security should be guaranteed at all times to ensure that they put in their best in the performance of their official duties to the benefit of their libraries. Keywords: Job satisfaction, Librarians, Federal Universities, University libraries.

APA, Harvard, Vancouver, ISO, and other styles

42

Yerokun, O. M., and M. O. Onyesolu. "On the Development of Neuro-Fuzzy Expert System for Detection of Leghemoglobin (NFESDL) in Legumes." advances in multidisciplinary & scientific research journal publication 9, no. 1 (January 24, 2021): 1–14. http://dx.doi.org/10.22624/aims/digital/v9n1p1.

Full text

Abstract:

The regular supply of affordable complete meals most especially protein from animals has been threatened. Protein sourced from animals carry too many health risks. Obesity, cancer, diabetes, etc., have been traced to the consumption of meats, most especially beef. Medical experts claim that some ailments are as a result of the chemically processed feeds given to raise animals. Therefore, an alternative to meat from plants is imperative. This led to the development of a neuro-fuzzy expert system for detection of leghemoglobin in legumes. This work utilized production rule-base technique and forward-chaining mechanisms with linguistic antecedent conditions to detect the presence of leghemoglobin in plants. To further remove clumsiness and ambiguity in the identification process, metrics/weights were obtained and attached to each morphological feature. MATLAB platform was employed for the development of the system. Class and objects were used to model the information elicited. The result is a system that detects the presence of leghemoglobin in plants. Keywords: Expert system, inference system, neuro-fuzzy, dataset, leghemoglobin

APA, Harvard, Vancouver, ISO, and other styles

43

Van Loo, Rory. "Digital Market Perfection." Michigan Law Review, no. 117.5 (2019): 815. http://dx.doi.org/10.36644/mlr.117.5.digital.

Full text

Abstract:

Google’s, Apple’s, and other companies’ automated assistants are increasingly serving as personal shoppers. These digital intermediaries will save us time by purchasing grocery items, transferring bank accounts, and subscribing to cable. The literature has only begun to hint at the paradigm shift needed to navigate the legal risks and rewards of this coming era of automated commerce. This Article begins to fill that gap by surveying legal battles related to contract exit, data access, and deception that will determine the extent to which automated assistants are able to help consumers to search and switch, potentially bringing tremendous societal benefits. Whereas observers have largely focused on protecting consumers and sellers from digital intermediaries’ market power, sellers like Amazon, Comcast, and Wells Fargo can also harm consumers by obstructing automated assistants. Advancing consumer welfare in the automated era requires not just consumer protection, but digital intermediary protection. The Article also shows the unpredictable side of eliminating switching costs. If digital assistants become pervasive, they could gain the ability to rapidly direct millions of consumers to new purchases whenever a lower price or new innovation becomes available. Significantly accelerated consumer switching—what I call hyperswitching—does not inevitably harm society. But in the extreme it could make some large markets more volatile, raising unemployment costs or financial stability concerns as more firms fail. This new kind of disruption could pose challenges for commercial and banking regulators akin to those familiar to securities regulators, who deploy idiosyncratic tools such as a pause button for the stock market. Even if sellers prevent extreme hyperswitching, managers may strategically prepare for hyperswitching with economically costly behavior such as hoarding liquid assets or forming conglomerates to provide insurance against a sudden exodus of customers. The transaction-cost-focused literature has missed macro-level drawbacks. The regulatory architecture reflects these scholarly gaps. One set of agencies regulates automated assistants for consumer protection and antitrust violations but does not go beyond those microeconomic inquiries. Nor do they prioritize strengthening digital intermediaries. Regulators with more macroeconomic missions lack jurisdiction over automated assistants. The intellectual framework and regulatory architecture should expand to encompass both the upsides and downsides of digital consumer sovereignty.

APA, Harvard, Vancouver, ISO, and other styles

44

Koyama, Tomomi. "Digital Native / Digital Immigrant." Japanese Journal of Radiological Technology 68, no. 12 (2012): i. http://dx.doi.org/10.6009/jjrt.2012_jsrt_68.12.i.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Figueiredo, Ângela Dos Santos, Rubivaldo Ramos Dos Santos, and Clebson Dos Santos Simplicio. "O processo de letramento digital em uma turma do 5º ano do ensino fundamental." Revista Científica Multidisciplinar Núcleo do Conhecimento 03, no. 12 (December 12, 2019): 44–52. http://dx.doi.org/10.32749/nucleodoconhecimento.com.br/educacao/letramento-digital.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Hwang, Y., C. Tsai, H. Wei, Y. Wan, and H. Liu. "SU-E-I-47: Quality Survey Using DIGIMAM Phantom for Digital Mammographic Systems." Medical Physics 42, no. 6Part6 (June 2015): 3252. http://dx.doi.org/10.1118/1.4924044.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Yu, Xinguo, Wan Ding, Zhizhong Zeng, and Hon Wai Leong. "Reading Digital Video Clocks." International Journal of Pattern Recognition and Artificial Intelligence 29, no. 04 (May 20, 2015): 1555006. http://dx.doi.org/10.1142/s021800141555006x.

Full text

Abstract:

This paper presents an algorithm for reading digital video clocks reliably and quickly. Reading digital clocks from videos is difficult due to the challenges such as color variety, font diversity, noise, and low resolution. The proposed algorithm overcomes these challenges by using the novel methods derived from the domain knowledge. This algorithm first localizes the digits of a digital video clock and then recognizes the digits representing the time of digital video clock. It is a robust three-step algorithm. The first step is an efficient procedure that directly identifies the region of the second digit at a very low computational cost, which replaces the traditional tedious image processing procedure of identifying the second digit region. The success of the first step mainly leverages on the novel second-pixel periodicity method. Using the acquired second digit region as input, the second step is a clock digit localization procedure. It first acquires the colors of the digits of the digital video clock and performs the color conversion. Then it localizes the remaining clock digits. Finally, the last step is a clock digit recognition procedure. It first employs an enhanced digit-sequence recognition method to robustly recognize the digits on the second; it then adopts a deep learning procedure to recognize the remaining digits. The proposed algorithm is tested on a prepared benchmark of 1000 videos that is publicly available and the experimental results show that it can read digital video clocks with a 100% accuracy at a low computational cost.

APA, Harvard, Vancouver, ISO, and other styles

48

Petrova, Iryna, Olena Balyka, and Hanna Kachan. "Digital economy and digital employment appearence." Social and labour relations: theory and practice 10, no. 2 (November 24, 2020): 10–20. http://dx.doi.org/10.21511/slrtp.10(2).2020.02.

Full text

Abstract:

The article reveals the central role of information and communication technologies in the economy of the country, which have long become an important component of each person’s life and is a defining characteristic of digital transformation. The basis of digitalization is the digital presentation of data, which leads to better quality of life and economic efficiency of the individual country and the world as a whole. The article analyzes the specific features of digital economy and stipulates the consistency of creating the digital employment. It has been determined that the development of the digital economy and digital technologies leads to changes in all spheres of human life, predominantly in employment relations, manifested in the appearance of digital workplaces, workers with digital competencies, specific relations in the digital segment of labor market. The results of the work in the digital segment are the technologies, products, and services, some of which are analyzed in the article (eHealth, digital insurance, e-security, e-rights and e-technical passport, smart cities, SmartFactory – smart production, digital workplace, blockchain, “GAFAnomy”). In the digitalization process, the employment acquires the multivector flexibility, and has both positive and negative consequences. Taking these consequences into consideration is necessary for regulating the economic and social sphere.

APA, Harvard, Vancouver, ISO, and other styles

49

Ziolkowski, Natalia, Jana Dengler, and Cory S. Goldberg. "Digit Necrosis After Hand Surgery in Pregnancy: A Case Report." Plastic Surgery Case Studies 7 (January 1, 2021): 2513826X2110270. http://dx.doi.org/10.1177/2513826x211027015.

Full text

Abstract:

Digital blocks are routinely used for excision of lesions. We describe a unique presentation of digit necrosis after excisional biopsy with digital block and finger tourniquet in a pregnant patient with a history of ulcerative colitis. The patient had a history of a long-standing painful dorsal PIP joint mass and was scheduled for excision under local anaesthetic. On the day of the procedure, she disclosed that she was pregnant in the second trimester. After extensive discussion of risks and benefits between the patient and the surgeon, the decision was made to proceed with an excisional biopsy of the lesion because of its impact on her quality of life. Twelve hours after the procedure, she presented to the emergency department with blistering and severe pain to the digit. Doppler ultrasound showed flow through both digital arteries and the digit appeared viable. Over the coming days her pain continued to worsen and on post-operative day 3, she was admitted to hospital for attempted salvage of the digit using conservative methods. Her digit went on to demarcate at the level of the middle phalanx. Five weeks after her initial procedure, the patient underwent partial amputation of the small finger at the level of the DIP joint and 2-stage groin flap for soft tissue coverage. We discuss the effects of pregnancy and ulcerative colitis on thromboembolic events, and review the literature on digital blocks, digital tourniquet use and management of early digit necrosis. This case highlights the importance of delaying elective hand procedures in pregnant patients, especially if they have additional comorbidities such as pro-thrombotic diseases like inflammatory bowel disease.

APA, Harvard, Vancouver, ISO, and other styles

50

Guan, Xiaochun, Jianlin Huang, and Tinglong Tang. "Robot vision application on embedded vision implementation with digital signal processor." International Journal of Advanced Robotic Systems 17, no. 1 (January 1, 2020): 172988141990043. http://dx.doi.org/10.1177/1729881419900437.

Full text

Abstract:

The great development of robot vision represented by deep learning places urgent demands on embedded vision implementation. This article introduces a hardware framework for implementation of embedded vision based on digital signal processor, which can be widely used in robot vision applications. Firstly, the article discusses implementation of a pretrained typical convolutional neural network on the digital signal processor embedded system for real-time handwritten digit recognition. Then, the article introduces the migration of OpenCV software packages to digital signal processor embedded system and the implementation flow of face detection algorithms with OpenCV on digital signal processor. The experimental results are remarkable with convolutional neural networks for handwritten digit recognition. This article provides a convenient and feasible design scheme of digital signal processor system for implementation of embedded vision.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Digimat'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles