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Composites - Science topic

Production, Testing, Dimensioning, Research on Composites
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Dear colleagues!
I need help understanding the rheological properties of HDPE and LDPE-based composites.
Who studies the rheological properties of polymer composites, please let us know or tell a specialist in this field.
Best regards
Kuzmin Anton
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Ravi Purbey please write message my email kuzmin.a.m@yandex.ru
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I know fiber volume fraction in composites, but what is Yarn fiber volume fraction in ANSYS ?
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Yarn Fiber Volume Fraction (FVF) is the ratio of the fiber volume to the total yarn volume (including both fibers and voids).
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I am creating a single element model in Abaqus of a composite material. My goal is to match the stress-strain curve of the material which was obtained experimentally. I am using VUMAT for Fabric Reinforced Composites to get a non-linear stress-strain curve. However, every time I run my analysis I get the error "1 elements have missing property definitions". I tried changing the element type, hourglass stiffness, etc., but nothing seems to work. How can I solve this?
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Ahmad Bakir Would I be able to do that within Abaqus? Please let me know if you end up publishing a tutorial on this, it would be very helpful!
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2024 5th International Conference on Advanced Materials and Intelligent Manufacturing(ICAMIM 2024), which is to be held in Guangzhou, China, from November 01-03, 2024.
Conference Website: https://ais.cn/u/v6ve6r
---Call for papers---
The topics of interest for submission include, but are not limited to:
◕ Advanced materials
01) Non-ferrous metal materials
02) Steel polymer material
03) Composites
04) Micro/nano materials
05) Optical/electronic/magnetic materials
06) New feature materials
◕ Intelligent manufacturing
01) Biomimicry mechanisms
02) Integrated manufacturing systems
03) Industrial and manufacturing systems analysis and decision-making
04) Digital manufacturing
05) Modeling and design
06) Intelligent systems
07) Intelligent mechatronics
08) Micromachining technology
09) Advanced manufacturing technology
---Publication---
All papers, both invited and contributed, will be reviewed by two or three experts from the committees. After a careful reviewing process, all accepted papers of ICAMIM 2024 will be published in the Journal Of physics: Conference Series (ISSN:1742-6596), and it will be submitted to EI Compendex and Scopus for indexing.
---Important Dates---
Full Paper Submission Date: October 30, 2024
Registration Deadline: November 1, 2024
Final Paper Submission Date: November 10, 2024
Conference Dates: November 01-03, 2024
--- Paper Submission---
Please send the full paper(word+pdf) to Submission System:
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Dear Guohua zhang Zhang , Please submit the English version to the submission system: https://ais.cn/u/v6ve6r
After the submission, the paper will be reviewed to see if it is relevant to the conference topics.
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Is there a single JCPDS card for natural fiber ? My understanding is that all natural fibers basically have the same constituents albeit they are in different concentration. Cellulose, hemicellulose, lignin, pectin and wax. Natural fiber is a semi-crystalline material, so expect amorphous and crystalline indicators in the XRD graph.
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Natural fibers primarily consist of alpha-cellulose. The cellulose phase potentially alters based on treatments or processing conditions. The specific type of cellulose can be verified using the JCPDS file. This file is accessible for download via the accompanying software of the XRD machine. Within this software, JCPDS cards relating to all types of cellulose is available for manual comparison or automatic identification. The system handler can assist in extracting the JCPDS cards based on their licensing agreement.
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What technology is used for mixing synthetic rubber and polyethylene? Can you recommend literature or articles on this topic?
Thank you so much.
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Polymer blends can be prepared by a variety of techniques, which include solution blending, latex blending, mechanical blending, and mechanochemical blending. Among the different types of thermoplastic elastomers, those prepared by physical blending of an elastomer and a thermoplastic material under high shearing action have gained considerable attention due to the simpler method of preparation and easy attainment of the desired physical properties.
Thermoplastic elastomers based on high-density polyethylene (HDPE) and nitrile rubber (NBR) were prepared by a melt blending technique. These blends couple the elastic and oil-resistance properties of NBR and the excellent mechanical properties, ozone resistance, and processability characteristics of HDPE. Because the system is incompatible, technological compatibilization was sought by the addition of maleic- and phenolic-modified polyethylene. The compatibilizer locates at the interface and reduces the interfacial tension and, thus, provides improved adhesion between the phases. The experimental results could be applied to test the current compatibilization theories of Noolandi and Hong.
Please see this researches that might be useful:
· Polymer Science, Series D, 2019, 12(2), 223–225; DOI:10.1134/S1995421219020084
· Polymers, 2022, 14(12), 2457; DOI:10.3390/polym14122457
· J. App. Pol. Sc., 1995, V. 57, 449-465. CCC 002 1 -8995/95/040449- 17
Best regards,
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Hi,
I took some FTIR (ATR) readings of a polymer composite (epoxy+ fumed silica+ ceramic filler) we are working on. The peaks seem to decrease in intensity with increase in ceramic and filler content. I am new to FTIR but based on what I have read decrease in peak intensity corresponds to reduction of bonds which absorb that wavelength if so doesn't that mean these fillers are impeding growth of the polymer chain bonds? But I had a doubt that wouldn't these opaque particles being in higher concentration block the IR and reduce transmittance and then the decrease in peaks just means the IR was not able to penetrate the sample due to presence of these particles and not actual decrease in polymer chain formation. Can someone explain this to me.The attached graph is transmitance % vs wavelength Thank you.
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First of all you should clarify your operating conditions to avoid the unacceptable noise which has been observed your provided spectra. Then it could be much more benificial if you consider a comparative study among all the considered constituent / ingredient which you were incorporated in the polymeric composites individually for better understanding the actual behaviour of your final fabricated composites.
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Hi everyone, I want to ask how to use self-consistent clustering analysis method for concurrent multiscale simulations and how to solve Lippmann-Schwinger equation for this.
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If you can be specific on which analytical software or programming language you are using. Will try to answer accordingly.
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I have done parametric study in Ansys Material Designer by varying the volume fraction of carbon fiber. Now I would to have a look at stress distribution in the RVE for each design point. How can I view?
Thank you.
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Just use Mechanical APDL and view .rst file in Results Viewer
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The layup contains a biaxial non-crimp fabric (NCF) with orientations +45° and -45°. Would the correct notation be [(± 45)ncf ] , or should the fabric be noted like two separate unidirectional plies [+45/-45]?
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Sorry for the late answer, but I was not aware of the posed question.
See my added file please.
Best regards,Ralf Cuntze
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When it comes to material assessment, it's common to rely on fracture patterns from tensile tests. However, it's crucial to understand that these patterns are not inherently designed for fracture analytical purposes. Let's dive into why, despite this, they are still used, and the necessary shift towards more suitable approaches by this novel illustration.
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Martin Brandtner-Hafner, tensile tests are not specifically designed for fracture pattern analysis. This is because tensile tests are designed to measure the overall behavior of a material, while fracture pattern analysis is concerned with the behavior of a material at a local level.
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To date, I have only encountered academic literature pertaining to the Digital Image Correlation (DIG) of 2D or 3D smooth surfaces. Regrettably, I have yet to find any research publications regarding DIG analysis of rough surfaces.
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The Digital Image Correlation (DIC) technique is a powerful tool for analyzing the deformation and strain of a rough surface. GOM Correlate is a popular software package for analyzing DIC data. Here is a general procedure for using GOM Correlate to analyze a rough surface using DIC:
  1. Capture images of the surface: You will need to capture a series of images of the surface under investigation. The images should be taken from different angles and positions to ensure good coverage of the surface. You should also capture images of the surface before and after deformation or loading.
  2. Import images into GOM Correlate: Once you have captured the images, you will need to import them into GOM Correlate. You can do this by selecting "File" -> "Open Images" from the main menu.
  3. Define the region of interest (ROI): You will need to define the region of interest (ROI) in the images that you want to analyze. The ROI should cover the entire surface of interest. You can define the ROI using the "Region of Interest" tool in GOM Correlate.
  4. Apply pre-processing filters: Before analyzing the images, you may want to apply pre-processing filters to remove noise and enhance the contrast. GOM Correlate provides several pre-processing filters, such as Gaussian filtering, FFT filtering, and background subtraction.
  5. Set up the correlation parameters: You will need to set up the correlation parameters in GOM Correlate. This includes selecting the correlation algorithm, setting the search range, and defining the subset size.
  6. Compute the displacement and strain: Once the correlation parameters are set, you can compute the displacement and strain using GOM Correlate. GOM Correlate will generate displacement and strain maps for the surface under investigation.
  7. Analyze the results: You can analyze the displacement and strain maps to gain insights into the deformation behavior of the surface. You can also generate graphs and charts to visualize the results.
This general procedure should give you a good starting point for using GOM Correlate to analyze a rough surface using DIC. However, it is important to note that the exact procedure may vary depending on the specific surface and application being analyzed.
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If you look at a typical Ashby diagram, you will notice that the fracture toughness based on K-factor is superimposed on all material classes.
Is this an ingenious solution or is it too simple?
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The inclusion of fracture toughness based on the K-factor on an Ashby diagram can be considered an ingenious solution. The K-factor is a measure of the stress intensity factor at the tip of a crack and is a critical parameter in determining the fracture toughness of materials. By including this parameter on the Ashby diagram, it allows for a quick and easy comparison of the fracture toughness of different materials, regardless of their class or composition.
However, it should be noted that the K-factor only provides one aspect of the material's fracture behavior and other parameters such as crack growth resistance and microstructure should also be considered when selecting a material for a specific application. Additionally, the values on an Ashby diagram are typically plotted for a specific set of testing conditions and may not accurately represent the fracture toughness under different conditions. Therefore, while the inclusion of K-factor on an Ashby diagram is a useful tool, it should not be the only parameter considered when selecting a material for a specific application.
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I intend to perform mechanical tensile test for my polymer nanocomposites. Does there exists any ASTM standard to follow? Can I also know the dimensions of the specimen to be produced? Lastly, I intend to create a mould for the dog-bone shape. Can we get files online to create the dog-bone mould using 3D printer?
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Yes, there are several ASTM standards available for performing mechanical tensile tests on polymer nanocomposites. Some of the commonly used standards are:
  1. ASTM D638 - Standard Test Method for Tensile Properties of Plastics
  2. ASTM D3039 - Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials
  3. ASTM D882 - Standard Test Method for Tensile Properties of Thin Plastic Sheeting
The dimensions of the specimen depend on the specific ASTM standard chosen for the test. For example, ASTM D638 specifies the dimensions for Type I, II and III specimens. Similarly, ASTM D3039 and ASTM D882 specify the dimensions for different types of specimens.
Regarding the creation of a dog-bone mold using a 3D printer, there are several online resources available that provide files for 3D printing dog-bone molds. Some popular online resources include Thingiverse, GrabCAD, and MyMiniFactory. However, it is important to ensure that the dimensions of the mold are as per the ASTM standards to obtain accurate results.
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Hello, I am wondering if the Rule of Mixture equation is applicable to flexural strength and modulus of carbon fiber composites. If not, what model is the easiest one to predict the flexural properties? Thanks!
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In the case of flexural strength and modulus of carbon fiber composites, the Rule of Mixture equation may not be the most accurate method for prediction. This is because carbon fibers have a much higher modulus of elasticity and strength than the polymer matrix, which can result in a non-linear behavior of the composite.
A more accurate model to predict the flexural properties of carbon fiber composites is the Mori-Tanaka model. This model takes into account the size and distribution of the fibers in the matrix, as well as the interface properties between the fibers and matrix.
Another model that can be used is the Hashin-Shtrikman upper and lower bounds. This model is based on the assumption that the composite is made of a mixture of two phases: a stiff phase and a weak phase.
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polymer with inorganic material
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  1. Elemental analysis: Elemental analysis techniques, such as inductively coupled plasma (ICP) spectroscopy, can be used to determine the elemental composition of a composite material. These techniques can provide information on the relative proportions of different elements in the composite, including carbon, hydrogen, and other elements.
  2. Infrared spectroscopy: Infrared (IR) spectroscopy is a technique that measures the absorption of infrared radiation by a sample. By analyzing the absorption spectra of a composite material, it is possible to identify the functional groups present in the material and infer its molecular structure.
  3. Nuclear magnetic resonance (NMR) spectroscopy: NMR spectroscopy is a technique that measures the magnetic properties of atomic nuclei. By analyzing the NMR spectra of a composite material, it is possible to identify the types and proportions of different functional groups present in the material and infer its molecular structure.
  4. Mass spectrometry: Mass spectrometry is a technique that measures the mass-to-charge ratio of ions in a sample. By analyzing the mass spectra of a composite material, it is possible to identify the molecular formulas of the individual components present in the material.
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What will be the exact reason? Sodium Hydroxide treatment
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There are several reasons why the density and tensile strength of natural fibers can increase during alkali treatment:
  1. Swelling of fibers: Alkali treatment can cause the fibers to swell as they absorb water from the solution. This swelling can increase the volume of the fibers, which can lead to an increase in their density. The swelling can also increase the inter-fiber bond strength, which can lead to an increase in the tensile strength of the fibers.
  2. Removal of impurities: Alkali treatment can dissolve and remove impurities, such as lignin and hemicellulose, from the fibers. The removal of these impurities can make the fibers lighter and more porous, which can increase their density. The removal of impurities can also increase the tensile strength of the fibers by increasing the inter-fiber bond strength and reducing the number of weak points in the fibers.
  3. Modification of chemical structure: Alkali treatment can also modify the chemical structure of the fibers, such as by breaking down the crystalline structure of cellulose. This can lead to an increase in the tensile strength of the fibers by increasing the inter-fiber bond strength and improving the ability of the fibers to transfer load.
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Why do micro-cracks forms in the matrix zones of FRP composites?
(a) Is it a Defect ?
(b) Does it has any effect on the initiation of fracture during the load applied?
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Micro-cracks can form in the matrix zones of fiber reinforced polymer (FRP) composites for a variety of reasons. Some potential causes of micro-cracking in FRP composites include:
  1. Residual stresses: FRP composites can be subject to residual stresses that are induced during the manufacturing process, such as those caused by curing or cooling. These residual stresses can cause micro-cracking in the matrix zones.
  2. Environmental factors: Exposure to environmental factors such as temperature fluctuations, moisture, and UV radiation can cause micro-cracking in the matrix zones of FRP composites.
  3. Load-induced cracking: The applied load can cause micro-cracking in the matrix zones of FRP composites, particularly when the load is applied at a high rate or when the composite is subjected to cyclic loading.
Micro-cracking in the matrix zones of FRP composites may be considered a defect, depending on the specific context and the severity of the cracks. In general, micro-cracking can affect the mechanical properties of the composite, such as its strength and stiffness, and may also affect its durability and service life.
Micro-cracks can also play a role in the initiation of fracture during the applied load. In general, micro-cracks can act as sites of stress concentration, and may promote the propagation of larger cracks when the composite is subjected to further loading. This can ultimately lead to failure of the composite material.
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I am following ASTM D7264 for conducting Flexural strength test of natural fiber polymer composite. Initially support span to thickness ratio of 32:1 was planned but due to miscommunication 32:1 is now total length to thickness ratio. Now if I am using 20:1 which is also allowed as per the ASTM standard I will have 36% of total length as overhanging portion. The standard recommends about 20%, doesn't say if it os minimum or maximum. Does taking higher overhanging length effect the result?
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The standard does recommend that the overhanging length should be about 20% of the total length, but it does not specify a minimum or maximum value. However, it is possible that a higher overhanging length could affect the results of the test.
In general, a longer overhanging length may result in a higher bending moment at the point of maximum load, which could lead to higher flexural strength values. However, it is also possible that a longer overhanging length could result in additional bending deformation or failure at the outermost fibers, which could lead to lower flexural strength values.
Therefore, it is important to consider the effect of the overhanging length on the results of the test and to carefully follow the recommended guidelines in the standard. It may also be helpful to conduct additional tests with different overhanging lengths to understand how this parameter affects the flexural strength of the composite material.
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Hello everyone,
I want to investigate the debonding behavior of the matrix-particle interface in a particulate composite with spherical particles in a two-dimensional matrix, using the Abaqus Dynamic Explicit solver.
I used General Contact (Explicit), with cohesive behavior and Johnson -cook damage formulation. However, stress concentration is occurred at matrix, and the stress is not transferred to the particles. Also, interface perpendicular to force direction is deboned very early. I think my interface definition is not correct, any help would be highly appreciated.
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To define debonding at the matrix-particle interface using the cohesive surface method in Abaqus, you can follow these steps:
  1. Create a surface or surfaces in your model that represent the interface between the matrix and the particles. These surfaces should be associated with the matrix material.
  2. In the Abaqus/CAE interface, go to the "Material" tab and select "Cohesive Surface" from the "Material Type" dropdown menu.
  3. Define the cohesive surface properties, such as the normal and tangential stiffness, normal and tangential strength, and debonding energy. These values should be determined based on the material properties of the matrix and the particles and the desired debonding behavior.
  4. Assign the cohesive surface material to the interface surfaces in your model.
  5. Run the simulation and monitor the debonding behavior at the matrix-particle interface. You may need to adjust the cohesive surface properties and re-run the simulation if the debonding behavior is not as desired.
Keep in mind that the cohesive surface method is just one approach to modeling debonding in particulate composites. Other methods, such as the cohesive element method, may also be used depending on the specific needs of your simulation.
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Hello ResearchGate Community,
I am working on composite laminate analysis. Need to do a numerical analysis and the stacking sequence is given by the supervisor in the attached photo.
- If there is a + and - sign together (as in the case for 45 degree), then what to do?
- What to do during (0,90)?
- How the symmetry will work here?
I have some options (options given below), but not sure and don't have a clear explanation. Can anyone please help me and confirm it?
(1) 45/0/90/45/45/90/0/45/45/0/90/45/45/90/0/45
(2) 45/0/0/45/45/0/0/45/45/0/0/45/45/0/0/45
(3) 45/0/45/0/45/0/45/0/45/0/45/0/45/0/45/0
I thought to use only +45, so I have come up with these 3 options, but not sure~
Thank you a bunch in advance for your effort and time :)
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To stack the plies of a composite material in numerical analysis, you will need to use a software that is capable of modeling composite materials, such as finite element analysis (FEA) software. The specific steps will depend on the software you are using, but in general, you will need to follow these steps:
  1. Create a new model in the software.
  2. Define the material properties for each ply of the composite. This will typically involve specifying the material type (e.g. glass fiber reinforced polymer), the properties of the matrix material (e.g. Young's modulus and Poisson's ratio), and the properties of the fiber reinforcement (e.g. fiber volume fraction, fiber orientation, and fiber modulus).
  3. Define the geometry of the composite structure. This will typically involve creating a 2D or 3D representation of the composite structure, such as a flat panel or a cylindrical tube.
  4. Assign the material properties to the different plies of the composite. In most software, this will involve selecting the plies and assigning the appropriate material properties to each one.
  5. Define the loading and boundary conditions for the composite structure. This will typically involve specifying the applied loads and the supports or constraints that are applied to the structure.
  6. Run the analysis to calculate the stress and strain distribution within the composite structure.
  7. Review the results of the analysis, such as the stress and strain contours or the failure criteria.
To stack the plies in the specific stacking sequence of [(±45)/(0,90)]4s, you will need to define the orientation of each ply relative to the previous ply. For example, if the first ply is oriented at 45 degrees, the second ply would be oriented at -45 degrees, the third ply would be oriented at 0 degrees, and so on. The software will automatically calculate the resulting ply orientations based on the specified stacking sequence.
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I saw literature that frontal polymerization can be used in 3D printing of composites. The curing can be triggered briefly by external heat source, and the thermal front wave can travel from the external heat source side to convert monomer to polymer. How to control the heat rate in composites curing?
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Control the temperature.
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Dear researchers,
My research area is related to the development of metallic composites. I am switching to sensor development. Basically, I will work on the development of advanced materials for sensor applications. I need your guidance, suggestions, and ideas. I am also looking for collaboration in this area.
Looking for your valuable replies.
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We don't have any sensor development lab right now.
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My project is ballistic test of composite with fmj parabellum projectile. But my problem now is negative volume.. in help viewer of ansys noted that I must activate failure capabilities and use material strength limit.. how I can do that?
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You can use automatic surface to surface, or node to surface for contact
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I need to test tensile properties of woven bidirectionally woven fiber which will be used to prepare composites. How do I measure the tensile properties (tensile strength and modulus) of it ? There is a standard for tear strength D5587 − 15 that measures tear strength of partially torn fabric. But this cannot be related to tensile strength since tensile strength is actually stress that can be handled to resist yield or fracture (MPa). Tear strength is actually force needed to completely tear a already torn fabric. So, please let me know the suitable standard to measure tensile strength.
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ASTM D3039. It's preferred to test the sample in both warp and weft directions but in the interest of time and to save the sample cost, you can test in only one direction (in the case of plain weave only) as you will get the same results.
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concentrate with fiber orientation
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Prateek Saxena, for cured epoxy inside ACP module, what to choose sir?
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What characterization required for automotive anti-roll bar applications?
Mechanical, Dynamic mechanical, thermal etc and what is range of vales of these properties
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Dear Karthika P,
Don’t copy paste articles from Google on a subject which you don’t know anything. To understand Automotive Dynamic Systems is beyond your capability.
regards
jasbir s ryait
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I want to simulate composite laminates under cyclic loading, for 100K, and 200K cycles, then I need to extract the stress v/s number of cycle data. Can anyone please suggest how to proceed?
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Kariappa maletira karumbaiah You need to write the subroutine for fatigue simulation of composite materials. I know the tutorial which has prepared this subroutine along with software files and subroutines.This subroutine is based on SHokrieh's article titled "Progressive Fatigue Damage Modeling of Composite Materials, Part I: Modeling"
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If you are adding nanoparticle to a fiber based epoxy composite, what is the right way of deciding the weight percentage of the nanoparticle ? If you select with respect to the composite, then when you increase the fiber content, the fraction of nanoparticle in resin keeps on increasing which will have negative effect countering the effect of increase in fiber content. Say you increase fiber from 30 to 50 wt%, if you keep nanoparticle wt% with respect to composite as 1. In case of 50% fiber, since there is lesser resin, the dispersion becomes difficult. So best thing to do is select nanoclay with respect to the epoxy system. Which way is correct ? I believe I am correct.
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When applying Maximum Stress Criterion on ANSYS composite PrePost, I noticed that interlaminar stress limit (S3) accounted for by the software is 50% of the out-of-plane stress limit (Z) defined by the laminate properties. However, I didn't find any thing in the documentation that refers to the value of this weakening factor.
Can any one provide me with a reference for this assumption?
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I do not think there is a weakening factor. The values you have are depending on the material properties.
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Hey, i basically want to simulate a tensile test to validate the damage model of my composite material. When using the instant stiffness reduction the results converge but are not sufficent. Hence i want to use the "Continuum Damage" approach, for which you need to specify the energy release rates and damping coefficients for the 4 failure modes.
As soon as damage (hashin) initiates, the elements get highly distorted and the simulation exits with warnings: *** ERROR *** CP = 4.391 TIME= 12:35:59
Element 286 (SOLID186) is turning inside out.
for multiple elements.
Large deformations are on and i already tried increasing the substeps. I am using solid elements.
Why does this only happen with the continuum damage appoach? Does someone of you have experience with it regarding composites?
Thank you a lot in advance!
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I think Ansys support Continuum Damage models for only shell element. The ply discount model can be used for solid elements.
Also, ensure that you the local coordinate system of the materials.
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Dear ABAQUS users,
I want to make a three-dimensional model of the three-point bending simulation!
What do you think is the best element to use in ABAQUS for this problem? C3D8R - C3D8 - C3D20R - C3D20 - C3D8I
Can you please tell me about the advantages and disadvantages for each element or send me a reference for that!
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Three-dimensional (3D) eight-node solid C3D8 elements for concrete &
T3D2 elements for reinforcement are adequate to get the damage mechanism on the type of testing.
For a 4-point bending test, a numerical verification of CDPM in ABAQUS based on experimental results can be found here:
Bests,
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In order to analyze the effect of moisture absorption on mechanical properties of composites, need to follow ASTM D5229 and immerse in water till the composites saturate with moisture. This consumes time, 2-3 or even 6 months. Is there any other accelerated water absorption process which simulates the normal water absorption but at a different scale ? I cannot increase the water temperature beyond 40 degree celsius because ASTM recommends the water temperature to be 25 degree celsius less than the glass transition temperature.
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Visit also the following useful RG link:
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I'm currently modeling to plaques that are together, one is of a composite material and has ply orientation while the other is a simple mould with isotropic properties.
The type of element I'm using is C3D20T and the contact type I used is surface to surface with small sliding, frictionless, contact controls, hard contact and direct in normal behavior and zero tolerance specified. However, I get the following warning :
Solver problem. Zero pivot when processing D.O.F. 1 of 22 nodes. The nodes have been identified in node set WarnNodeSolvProbZeroPiv_1_1_1_1_1.
How can I solve it?
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Dear Brenda Gonzalez,
As Denis Benasciutti said, you get this error when you don’t use enough boundary conditions. I recommend checking this link for more info, especially the section 2.12 because it’s about your problem:
If you have problems simulating the composite or composite damage, it’ll be worth it to check the links below:
I hope I could have helped you.
Bet luck.
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I want to analysis Lamina composite with ABAQUS and for this reason I would like to export my file from Hypermesh to ABAQUS?
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Saman Khodabakhshi Can you share your Abaqus model (.inp)?
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currently  i am working on impact analysis of a Armour.I am using ANSYS autodyn for simulation but i am stuck in calculation of residual velocity.
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I highly recommend using LS-DYNA to simulate the ballistic impact
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I have mixture of nanoclay, acetone and epoxy LY556 kept in vacuum oven. What must be the pressure setting in mm of Hg so that only the acetone and air bubbles escape and not the resin ? Is 460 mm of Hg and oven temperature of 50 degree Celsius is fine ?
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Dear Muralishwara Kakunje,
You have to do your own testing because each vacuum oven could be very different and also your sample volume. What yoi need to do is to various vacuum pressures. Normally it shouldn't be too high. You can set 3 air pressure, 4 air pressure and 5 air pressure and etc to find the optimum performance at a fixed temperature such as 50 degree C.
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As per ASTM D3039 for tensile testing and D7264 for flexural testing of PMC, there are no strict requirements of maintaining 3 mm thickness. Is it an unwritten norm followed in publishing papers. In none of the papers i have seen thickness of say 2.5 mm. For flexural testicng, 4 mm is standard but one may change it as long as 32:1 length to thickness ratio is maintained. For tensile testing even though they recommend standard thicknesses, it can be changed.
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Dear Colleague,
the minimum thickness may seem arbitrary at first sight, it could be 2.5 or 3.5 mm as well. The idea behind the minimum thickness is that the thickness of the sample should be large compared to typical microstructure features and typical flaws. If one layer of fabric is 0.2-0.3 mm thick the sample size should be at least ten times larger to rule out random failure effects.
best regards
Frank
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Cement has been in human use throughout history, and due to its binding nature, it is regarded as the backbone of the construction industry. A recent edition of the journal Nano Energy published the results from major breakthrough research conducted by engineers from Incheon National University, Kyung Hee University, and Korea University. The researchers have invented a cement-based composite (CBC) that can be used in concrete to develop electrical properties without affecting its structural performance. But what if cement could be used to generate electricity?
Any ideas from researchers?
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How is GSM calculated ? What is the importance of selecting right GSM ?
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Grams per Square Meter (g/m2)
Weight of the fabric per unit area, by considering yarn crimp, yarn linear density in warp and weft direction, number of yarns per unit length etc..
It is greatly influence on mechanical and dynamic mechanical properties, thermal and dynamic mechanical properties of composites.
Plz look at my publications
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What is the type of nucleation in Polypropylene composites containing carbon black (less than 3 wt.%) during crystallisation and recrystallisation?
Is it homogeneous, heterogeneous, secondary nucleation?
Specifically in the laser transmission welding process.
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Dear Foram Dave, it is well known that nucleation reduces spherolites size, hence important enhancement of properties are imparted to a polymer known by its high and large crystalline size domains. Please have a look at the following attached paper. My Regards
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The piezoelectric charge coefficient (d) considers the directions of the applied force and polarization. However, ZnO is not a ferroelectric material, so I can't pole it with an external electric field. Therefore, how can I know the direction of the already existing dipoles to determine d33? I plan on using the Berlincourt method.
Moreover, I want to produce a Polyurethane/ZnO composite to enhance the material's flexibility. Is there any recommended synthesis method to this case?
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Oriented ZnO thin films made by sputtering are piezoelectric, you don't need electrically pole them like normal ferroelectric piezo-elements like PZT. PZT thin films are normally polycrystalline, hence you need to pole them. There are many papers in the literature on the measurement of piezoelectric coupling from ZnO films, and the measurement of piezo coefficient.
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Dear researchers,
I am working on Mg composites fabricated by powder metallurgy. I have investigated the wear behavior of Mg-based composites with variation in temperature. I observed that wear rate increased with an increase in the wear temperature. Can anyone explain me in detail, why is it happening? What is the mechanism? I am looking for your responses.
Thank you so much.
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Thank you, sir. But I don't understand your language.
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The traditional housing typologies make use of locally available construction materials such as wood, stone, and mud etc. for the building construction. Past earthquakes showed high seismic vulnerability to these existing masonry building typologies.
What is the different strengthening or safety measures that can be taken to enhance their earthquake resistance?
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Thanks P. Pravin Kumar Venkat Rao for your interest and nice discussion.
Big openings can be reduced as per the guideline. Regarding friction isolator one can try foundation isolation (one can try for insertion of distributed isolator stage wise below the base raft).
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Ansys Granta is not a free programme. Is there any other materials selection software that you would recommend, and what is the name of it? ( https://www.ansys.com/en-in/products/materials/granta-selector )
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Hi, If you mind take a look at tables of the following paper (all links and licenses are mentioned):
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As every keyword have certain experts associated with it, based on their area of expertise. Can we initiate a devoted section for research collaboration, especially for the calls requiring bilateral or multinational collaborator?
Presently, My group is looking for a German collaborator in the area of " High performance based C-C composites" on following call "http://www.dst.gov.in/sites/default/files/DST-DFG-JointCall-10AUG2018.pdf"
Finding it difficult to have a relevant and interested group from Germany. kindly text me if anyone finds this call interesting.
Please share how I should proceed to search for interested researchers from Germany, My present approach is searching research papers on said area and mailing to the researcher if find relevant.
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Prof. Ajitanshu Vedrtnam: In my opinion, the projects are more than enough instead of your suggested section.
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In a stress-strain curve of an FRP composite, mostly it is represented strain in terms of (%) rather than in (mm). Why it is represented in such a way?
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Strain is any kind of deformation, including elongation. Elongation is the word used if we're talking specifically about tensile strain which the sample deforms by stretching and becoming longer. Usually the percent elongation is calculated, which is just the length of the polymer sample after it is stretched (L), divided by the original length of the sample (L0), and then multiplied by 100.
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I have prepared magnesium green compacts from powders of different particle sizes. I observed that the green strength of compacts produced from fine powder was very low. Green compact splitted in two parts in the vertical plane during removal of green compact from the powder compaction dies. I repeated the experiment so many times and observed the same behavior. What can be the possible reason? Please explain.
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Green compacts of any powder compacts have low strength because no bonding is there between particles. The green compacts possess whatever strength is because of compaction force. The compaction force removes the empty spaces and facilitates mechanical interlocking of particles. Only after sintering strength is developed. So, change the design of the die for easy removal of green compacts.
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I am going to use a machine (orthogonal cutting) for carbon fiber reinforced epoxy tube having 60 degree fiber orientation. I need material having 50-70 mm outer diameter and 2 mm thickness tube.
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Hi Gobivel,
You may make an inquiry at Alfa Chemistry, they offer kinds of good-quality materials.
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Has anyone in your laboratory equipment a VERSA TESTER? made by SOILTEST.Inc (Evanston Ill. USA)? I am looking for its user manual... Any help is greatly appreciated!!!
See the attached file.
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Yes we have but can not use the apparatus
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Hello All!
I am trying to model a composite in Abaqus, and specifically trying to capture the fiber realignment on loading.
One of the approaches I am considering is to.homogenise the fiber layer, and define anisotropic material properties that rotate on loading. This coordinate system should rotate following the direction of a prescribed edge of each element.
What would be the best way to model this rotating material orientation?
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You can check the following link:
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In powder metallurgy, energy is consumed in powder production, ball milling, powder compaction, and sintering. Whereas in casting, the energy is consumed only in melting the ingot. In some of the papers, I have read that energy consumption is lower in powder metallurgy. How? Can anyone explain, please?
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Both processes involve heat and load and thus require energy input, but in powder metallurgy, the wastage of material is kept minimum, and major form of energy input is required for the sintering process. But, in casting process, excess materials after casting have to be removed, and repeatedly reused by melting the solid metals. All of this adds to the higher energy consumption for casting process compared to powder metallurgy.
But it is also important to note that both processes have their own pros and cons and the selection of the fabrication process depends purely on the application, product specifications and availability of fabrication facility.
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I have experimental data on diffusion of water into composite samples. To find diffusion coefficient I have fit Fick's Model to the experimental data using matlab curve fitting application. In some cases, adjusted R square values for different samples of the same composition are different, say 0.9 for one and 0.7 for the other. So, now what would be my diffusion coefficient ? Can I take the normal average or should I take weighted average depending on the R-square value or should I neglect the diffusion data with R-square 0.7 ?
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Hi Muralishwara Kakunje . I think the best is to take the average value + - standard deviation.
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I am searching for the thermal conductivity (W/(mK)) of Vf=60% IN‐2 EPOXY INFUSION RESIN composite at 20oC < T <100oC. Could you suggest me any relevant literature, please? Thanks,
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Elsewhere at this forum, I have suggested a mixture rule to estimate the thermal diffusivity for a composite after those of its components: https://www.researchgate.net/post/Why-the-thermal-diffusivity-of-polymer-composites-increases-with-filler-loading
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Can the 'k' & 'c' values be derived analytically using the volumetric data( % aggregate,%binder, %air voids,% PP replaced) for a hot mix design?
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Elsewhere at this forum, I have suggested a mixture rule to estimate the thermal diffusivity for a composite after those of its components: https://www.researchgate.net/post/Why-the-thermal-diffusivity-of-polymer-composites-increases-with-filler-loading
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The Fick's equation is attached as JPEG file. Mt & Minfinity are water uptake of immersed specimen at time t and time infinity. n is number of readings. D is diffusion coefficient. t is time and l is specimen thickness.
How can I fit the equation or model to experimental data and see if the experiment follows Fick's law.
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To program Fick´s equation, I only considered the first seven terms of the series (up to n = 6). Analyzing the mathematical properties of this function, I found that this approach (up to n = 6) represents a very well-approximation to the real function for n = inf. So, you can write in the Origin Fitting Function Builder as:
y = 1 - (0.81057/((2*0+1)^2))*exp(-(D)*pi^2*(t/(4*l^2)*(2*0+1)^2) ) - ...(0.81057/((2*1+1)^2))*exp(-(D)*pi^2*(t/(4*l^2)*(2*1+1)^2) ) - ...(0.81057/((2*2+1)^2))*exp(-(D)*pi^2*(t/(4*l^2)*(2*2+1)^2) ) - ...(0.81057/((2*3+1)^2))*exp(-(D)*pi^2*(t/(4*l^2)*(2*3+1)^2) ) - ...(0.81057/((2*4+1)^2))*exp(-(D)*pi^2*(t/(4*l^2)*(2*4+1)^2) ) - ...(0.81057/((2*5+1)^2))*exp(-(D)*pi^2*(t/(4*l^2)*(2*5+1)^2) ) - ...(0.81057/((2*6+1)^2))*exp(-(D)*pi^2*(t/(4*l^2)*(2*6+1)^2) ) ; with 0.81057 ≈ 8/π2
where time (t) is the independent variable and y = Mt/Minf the dependent one.
l is the specimen thickness in [mm] and D the diffusion coefficient in [mm2/s]. To ensure good convergence of the function, l must be set as a fixed parameter. So, D will be given by the fit.
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I am currently using the asymptotic homogenization method to predict the elastic properties of a porous structure. The software I've been using only supports homogenization of an RVE with an isotropic base material, but in reality the base material will be transversely isotropic (the elastic constants of this material are known). Is there any way to take the compliance matrix resulting from the homogenization with an isotropic material and transform it to account for the transverse isotropy of the base material? For instance, if I know the Zener ratio of the base material, can that somehow be used to transform the structure properties?
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which type of shot (balls) will be used in shot blasting of sheet made up of Composite((Aluminum alloy +boron carbide composite) or for (Aluminum alloy +silicon carbide composite)
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At the first, it's important to determine the Hardness value of material (your composite) and then, according your material and it's hardness choose the shot ball type.
For a sheet which is made by aluminum matrix composite, the deformation and distortion must be considered
What is your opinion about low carbon steel ball?
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Composites experts 
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It depends on the particle size. if the particle size is less than 10 micron, one can effectively disperse 5vol.% in the matrix. If the particle size is more than 50 micron, then the close to 25 vol.% can be added.
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im currently modelling a hybrid composite RVE. it is just a simple model generated using the GUI. im having trouble generating the stress strain curve. i want the stress strain curve for the whole RVE and not just for 1 element.
thanks
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Ikmal hijaz Khalid , In order to generate the homogenised response of the whole RVE solved numerically you need to do the following procedure through Scripting. For each family of constituents (fibre, matrix) calculate the averaged stress and averaged strain from the formula <si> = Sum(sj* dVj)/Vi, <ei> = Sum(ej* dVj)/Vi
where i Is the component family e.g m for matrix f for fibre , j is the current element of the sum, sj is the stress of the element j, ej the strain of element j, dVj is the volume of the element j, Vi is the total volume of the elements of family i. Finally the total macro stress and total macro strain
stot = [Vf (<sf>) + Vm(<sm>)]/(Vf+Vm), etot = [Vf (<ef>) + Vm(<em>)]/(Vf+Vm).
This gives a point (etot, stot) for the curve. For linear analysis you only need two points. (0,0) and (etot, stot). In case of non linear analysis the above procedure should be performed for each time increment and collect all points (etotn,stotn) for the curve.
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Hi everyone
Aiming to model the IR radiative heating of composite sheets, I first started with a simple model : a cylinder above a solid sheet, in 2D with a Heat-Transfer step [Capture 1]. The cylinder has an imposed temperature of 600°C. I set a radiation interaction between both solids, whose parameters can be seen on Capture 2. I then tried to add another solid to act as a radiation protector, just like a sunshade does, but as expected, this doesn't prevent the lower sheet to receive radiative heat [capture 3].
  • Does anyone know how to properly set radiative interaction parameters ? I tried my best to implement realistic values from documentation for view factor but I am still doubtful about this model.
  • Is it possible to make Abaqus understand that one solid can "hide" a part of another solid from the radiative source ? Ofc I could partition the lower solid to apply radiative interaction only on the exposed surface, but I'd rather solve the problem than going around it.
Best regards,
Théophile
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Dear Victor
Thank you for your reply. I will look for it.
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Hello all!
How to model a composite model with a high strain rate (explicit dynamic analysis) in ANSYS or Ls-Dyna.
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Try the suitable element that convey your material and input your stress strain data
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 Exact ASTM standard for impact strength and flexural strength 
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Charpy and izod for impact test.
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I want to cut epoxy filled nanocomposite for FE-SEM analysis. What is the best way to cut it without resulting in any cracks or change in position or alignment of the particle reinforcement ? Also the cutting method must not burn the material.
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Dear all, cryocutting microtoming is the usual way of preparing SEM slides. My Regards
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Does Epoxy clay nanocomposite sample require surface preparation. I am going for Gold sputtering to make the surface conductive. I guess there is no need to clean or polish the surface beneath the conductive coating. Is there anything else that I need to do ? What about the thickness of the specimen ? If the specimen is 2 mm thick, do you think the nanoclay would not be accessible for the secondary electrons ? So, should I go for very lesser thickness ?
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The range of secondary electrons depends on energy. The secondary electron range is on the order of a few nanometers in metals and tens of nanometers in insulators
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Hello friends Good time. I need some issues with the genetically modified goat breeds(composite or synthesis) in the world. Please help me.
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I have worked on native goat breeds like Purgi, Kashmir Goat etc
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1. In a Low-velocity impact test, I have got Force vs Time response. There were two peaks in cross-ply and angle-ply orientation. In cross-ply, its peak to peak distance is lesser when compared to angle-ply. What is its significance?
2. Another was, steep rise in the cross-ply but the linear increment in angle -ply. What might be the reason?
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higher stiffness
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What are some of the current available research grant opportunities(i.e. name of funding organizations, process for availing funds, special eligibility requirements(if any)) for M.Tech (Mechanical) students in India?
Any information regarding it would be highly appreciated.
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MHRD Scholarship for M.E., M. Tech. Students
As per the directives of the Ministry of Human Resource Development (MHRD), Government of India, the following procedure is to be adopted for admission to post graduate programmes (Master’s and Doctoral ) with MHRD Scholarship assistantship.
Scholarship provider
Ministry of Human Resource Development (MHRD) Organization Government of India
Eligibility criteria
A candidate is eligible for Ministry of Human Resource Development (MHRD) Scholarship/Assistantship if he/she has qualified GATE. To avail the scholarship assistantship, additionally, the candidate must secure admission to such a postgraduate programme, as per the prevailing procedure of the admitting institution. GATE qualification by itself does not guarantee admission. GATE qualified candidates in Engineering disciplines are also eligible for the award of Junior Research Fellowship in CSIR Laboratories.
Benefits of scholarship/Award
  1. ME/M.Tech./M. Pharm : Rs. 5,000/- per month.
  2. D. with M. Tech. : Rs. 9,500/- per month.
  3. Without M. Tech. : Rs. 8,000/- per month.
  4. Contingency Grant: ME/M.Tech./M. Pharm : Rs. 5,000/- per annum.
Ph. D. : Rs. 20,000/- per annum.
Application Procedure
Candidates are advised to seek details about admission procedures and availability of MHRD Scholarship/ Assistant-ship from the Department of their interest or post-graduate office of the concerned institution.
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For above said properties what are the parameters need to be considered? Is the weight is the only parameter to calculate the % of  Chemical Resistance, Swelling, and Moisture Absorbance Behavior for Polymer Composite Materials?
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Hi. Regarding the moisture uptake and swelling of composites, we did an experimental and modelling study, providing insight into orthotropic hygroscopic swelling of fiber-reinforced composites. Could be potentially interesting for researchers in this discussion:
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I made a composite with micro particles of Ag and want to simulate it in ABAQUS software, but i encounter with a problem that can't model powder's particles of Ag.
Is it possible to simulate powder particles in ABAQUS software?
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I have a DSC curve for the resol resin matrix attached with the file. The heating rate at DSC was about 10k/min.
How do I choose the Autoclave parameters for curing of Glass fibre resol composites.
Which thermogram curve should i used for the curing of the resol resin.
Could someone interpret the DSC and TGA curve of the resin and tell me how to choose the parameters.
Thank you
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Dear Linto George Thomas, you asked for interpret the curves and it's hard to interpret that is what i mean
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We know that fiber-based composites are directional dependent, What happens when the load is applied in the normal direction? If fiber is strong enough, whether it will give the same results irrespective of the direction?
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Dear all, I have a small addition to what Dr. Pierluigi Traverso recommanded. When fibers are unidirectional, stress testing in normal direction to the fiber is done mainly to test how is the interface fiber-matrix, i.e., the state of adhesion at the interface and its coherency in stress transfer. My Regards
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Hi Everyone,
My attempt to use the drapability and stretching behavior of knitted composites(just fiber without matrix) in die forming. At this moment, I am only interested in the behavior of the fiber.
I ran 2 models (geometrically, constraints and interaction are identical).
Job 68-
Material model used (Steel with plasticity defined).
Results: Are converging. The behavior is as expected.
Job 69- Material model used (Carbon fiber-MAT-1 in .inp and material orientation defined based on texgen software algorithm). Added orientation by calculating the normal for each element using the node data. I have defined the material parameter based upon the property sheet from attached Hexcel-tow data.
The error I get is ratio of deformation speed is too high. I have tried a number of possibility as mentioned in this forum earlier. Any help would be highly appreciated:-)
-Sangram
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I think the mentioned error comes from element dimensions, run the simulation by default element and check the results.
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I have submitted my paper to a conference. I have studied the effect of varying the sonication amplitude (%) or power variable on the so and so of the nanocomposite. The reviewer wants to mention what does 100% mean with relation to frequency..or when I say 50%, how much frequency is it? The frequency mentioned in the brochure of the equipment is 20 kHz. Does 50 % amplitude mean a frequency of 10 kHz? As per my understanding, the amplitude is the distance moved by the transducer. The maximum or 100% amplitude is not given in the brochure or the company website. Does the frequency vary linearly with the amplitude or is it a constant?
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All ultrasonic cleaners/sonicators run at a fixed frequency. Typical cheap ones at 20 Khz. More expensive at 40 Khz. And the most expensive have a sweep generator that varies the frequency by 1000 Hz around 40,000 so it goes back and forth between 39,000 to 41,000. If you have a cheap one, it will only run at 20 KHz and the amplitude or power level is how much voltage you give the transducers which is directly proportional to how much they expand and contract, which correlates to how much power goes into the liquid.
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I am working on AA7050 based MMC, and I am confused with the type of Heat treatment like T6,  Etc . kindly suggest.
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please see this reference:
"ASM Metals Hand Book Volume 2 - Properties and Selection Nonferrous Alloys"
pages 438-448.
best regards
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I studied the crystallization mechanism of the ZSM-5/SAPO-34 composite, and I can't find any information about the effect of these two zeolites on the crystallization mechanism of each other. can anyone help me? i don't even know that the crystallization mechanism is changed in composite synthesis in comparison with individul zeolites or not.
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