FRP - Science topic

Hi Nils,

Sorry for the delayed response.

Please find attached (.inp) file.

Thank you,

Saharsha.

Merugikan. Sebab FRP merupakan kuat tarik dan tidak punya kapasitas tekan

I interested. Did you find the answer. Thanks

You should also be aware of the failure mode of FRP. the values you are seeking would be important when your failure mode is governed by FRP debonding. If you expect FRP rupture, you can consider as perfect bond (i.e. fixed contact surface) between interface of the FRP, matrix and concrete substrate.

Bests

Adjunto una imagen que podría ayudar a tu interrogante:

have u checked with the contact technology? bonding, bonding always, separation... do look into these..

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:

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.

Hi Yonatan,

Please check the D7205/D7205M “Standard Test Method for Tensile Properties of Fiber Reinforced Polymer Matrix Composite Bars”. This test method replaced the old B.1 and B.2 methods in ACI 440.3R for tensile properties of GFRP bars. ASTM D7205/D7205M also provides the recommended dimensions for the steel tubes you may use for each bar diameter.

Regards.

Dear

can you explain how to model bond-slip with two or more segments in Abaqus software?

my question is as same as the link below:

Dear Raheel,

For your GFRP part, the Hashin Damage in Abaqus (both initiation and evolution) can be used only with Continuum Shell elements (and not the 3D Stress/C3D8R elements). You need to create a new Section with category of Shell and Type of Homogeneous or Composite. Then you need to replace this newly created section with your existent GFRP Section for your RHS Part. Next, you need to change your Element Type (in Mesh Module), for your RHS part only, to Continuum Shell/SC8R (you can find it in the Family list in the Element Type window).

I hop this helps!

try to heat the resin as uniformly as possible - notice that temperature must not exceed the resin's boiling point!

Leonardo

Synthetic fibres are available in two forms (i) staple cut ( discontinuous) and (ii) infinite long length filament ( continuous). The staple cut fibres could vary between 38,44,51, mm for making them compatible to cotton fibres and 68 to 120 mm for mixing them with wool fibres. Short fibres are those which are < 12.5 mm.

Dear Mehmet Kösem, the best methods are those named real-time monitoring reaction progress, mainly gas chromatography and infrared spectroscopy. An old method is the iodometry which quantify the amount C=C. Details are presented in polymerization textbooks. My Regards

Dear Rameshbabu C , Yes all parameters you stated increase.

I do not think there is a weakening factor. The values you have are depending on the material properties.

thank you

Depending on the type of analysis, you need to define a constitutive model for each material, and in some cases the constitutive model allows you to predict the failure. Dependiong on this you can see a stress distribution plot and see which material attained its ultimate strentgh first at ultimate load state. Check also teh previous response.

Regards,

CG

Xiaojun Fang

Thanks for your advice. I will apply that in my model.

best regards.

It is not clear from your calculation whether the contribution of FRP has been accounted for. Besides, provide more details regarding the material properties and boundary condition for better assistance.

Dear Hamed Hasani

Kindly check these papers also:

Also, you might check this

More information might be in this link

The answer of your question might be found in this reference,,

Dear Izzet,

If you are planning for the simplified micro model, I will suggest using the FRP strengthened masonry properties as the brick unit properties. As you will model the mortar as a cohesive surface, no need to model the separate FRP rods. Otherwise, you will be needing lots of input properties.

Another option is to model each layer with different cohesive properties if you have all these material inputs.

Regards,

Bonisha.

Hi Silmon Tsegai,

Be careful - you mention short fibre reinforcement, i.e. discontinuous; the Hashin criterion is applicable to continuous, unidirectional composites only, as are the vast majority of "fibre-reinforced composite failure criteria" you will find in the literature (because, as we know, continuous fibre-reinforced composites are much more efficient in terms of strength and stiffness and thus of wider practical interest). If you are dealing with a 'chopped' fibre-reinforced plastic, you will need to research applicable models, which I personally do not have experience in, nor have I come across such models.

If in fact you are interested in a continuous, unidirectional composite, then note that the Hashin criterion is conveniently built into Abaqus but for plane stress only. It is simple enough to determine the Hashin failure coefficients in 3D by exporting the principal stress results from your solid model analysis into, say, Excel, and calculating using the 3D criterion, which should be taken directly from Hashin's original 1980 paper (https://doi.org/10.1115/1.3153664). I have used this approach many times. The Hashin criterion is considered to give a good evaluation of failure since phenomenological failure modes and stress interactions are accounted for. However, for a uniaxial tensile test, it should be reasonable to evaluate failure based on the Maximum Stress criterion i.e. compare your principal longitudinal stress with the corresponding strength to assess if failure occurs. To reiterate, these criteria are applicable to continuous fibre composites only, so you should make certain of the type of model you seek before consulting the literature.

Hope this helps.

JCH

The portion of the slab which acts integrally with the beam to resist loads is called the Flange of the T-beam or L-beam. The portion of the beam below the flange is called as Web or Rib of the beam. The intermediate beams supporting the slab are called T-beams and the end beams are called L-beams.

Dear Ali Reza Daneshkhah kindly look at these papers, it will be useful:

Dear Mr Shen,

wettability of the resin has a significant effect on the resulting fiber-reinforced polymer (FRP) bars and plates, any composite in fact for that matter. First, the choice of epoxy resin depends on which fibers are to be used, e.g., glass, carbon, basalt, etc. considering their wettability. Second, once an appropriate choice is made for the epoxy resin to make a composite from the given type fiber(s) then wettability is further improved through modifying surface properties by employing some chemical treatment and/or by exposing to high temperatures, depending upon the characteristics of both, the type of fibers as well as the epoxy resin. These processes to improve the adhesion between the fibers and surrounding matrix largely depend on a specific case in hand for study, and has no unique solution as such. In your case, please see which epoxy resin would be more suitable for the type of fibers you have with you based on the wettability criterion, and then improve their coupling additionally by further employing the surface, chemical, and thermal treatments, whichever is/are feasible. Hope this would work for you. All the best.

With best regards,

Vasant Matsagar.

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.

Hi dear Sudipto Kumar Paul

The following article can help:

Dear Ravi SHANKAR Rai, the best hardners for epoxy resins are thiols (mercaptans) and aliphatic amines. Acids and their anhydrides are also used. Literature on these systems are straight via simple search. My Regards

Painting it black or some other material that absorbs light energy.

Kindly work on materials like concrete, engineered timber and vibration induced cracks modelling.

Hello, find the softwares like PLAXIS3D, FLAC3D and also ABAQUS are useful for simulating your problem..ok all the best in your research..

Hi,

Congratulations, It's a good idea for increasing the flexural capacity of RC beams.

"The efficacy of hybrid near-surface embedded/externally bonded (NSE/EB) fabric-reinforced cementitious matrix (FRCM) for flexural strengthening of reinforced concrete (RC) beams was assessed experimentally"

Good luck

Milad

Hi Sir,

One of the important issues for the implementation of FRP reinforcements is to check the bond strength of longitudinal rebars with concrete. I suggest you read the following article for more information if you have any questions you can ask.

Good luck

Milad

Hi Sir,

you can use the keywords related to your favorite fields on this site: https://www.sciencedirect.com/ and Get the latest articles you want, then after reading these sources, create a new topic with the initiative.

Good luck

Milad

Dear Christi,

I just came across your very interesting technical question. I fully agree with the other expert RG members in that there is no single "perfect" FRP (= Fiber-Reinforced Polymer). The variety of known FRPs is just too large. For a highly instructive overview of this field please have a look at the following useful article:

This paper has been published Open Access, so that it is freely accessible as pdf file (see attachment).

A large number of other helpful references about this topic can also be found and accessed by searching the "Publications" section of RG. Simply search for the term "Fiber-Reinforced Polymer Composites" and then click on "Publications":

A large number useful articles about this topic have been posted by RG members, many of them even as public full texts.

I hope this helps. Good luck with your research work and best wishes!

Dear Arif Alam ,

Have you read the following paper?

Bdeir, Zeid. “Deflection-Based Design of Fiber Glass Polymer (FRP) Composite Sheet Pile Wall in Sandy Soil.” (2001).

If that article is not related to your work, please inform me.

Regards,

Ali

Mehran Shahpari , in Poland

I know ruredil system, I've used PBO fibers in my previous research. Now I'm looking for hemp fibers.

Dear Ahmed Mohamed Jubartalla Ali,

Thanks for updating me, and I really appreciate your cooperation.

Best regards,

Aziz

why don't you use the ATENA-GID interface to model FRP?

I am searching the same problem.

I think this article will be useful.

It explain PCI 2010 material model and Power Formula model.

Ashadul Islam

Yes, I said it increases the "mechanical properties" of concrete, which are compressive, tensile, and flexural strength.

Concrete novel additives, be it mechanical like steel fibers or chemical powder like nanoparticles, don't have Codes' approval yet. Hence, don't expect to see these additives in real projects.

Ferhat Aydın thank you very much.

The amount of resin by volume in FRP reinforcements is 60-70%.

After calculating the bar volume, you can accept 70% of the value you find as the resin volume.

Osama Ahmed Mohamed, can you please give some more information on the model - what do you use it for, are you modeling separate elements or entire structure, etc. The choice of program is strongly dependant on the goal. For everyday design purposes ANSYS is realy heavy, I agree, but it may be just what you need for more complex reaserch models, for example if you need to explicitly model the concrete-FRP conection. It takes time to get things working sometimes.

Else, if your priority is time and efford, you can also model your structure as reinforced concrete one with your prefered finite element or building information program with some adjucement of the input data (again, depending on what are you aiming at)

I believe this to be the norm, rather than the exception. The observed initial creep is due to slippage in the grips and the measuring device. The "true" creep comes later, and is very small indeed, next to zero.

Dear Md Iftekharul Alam

Did you find a solution to your problem?

Regards

Ahmed

Hello, does this question require more explanantion?

Thank you

Hi Venkataramudu，

did you solve this problem? I have same problem now.

If you are using the fifth version of ATENA you can use GiD as pre-processor commercial software to make your model. GiD 11.0.7 and GiD 11.0.8 are compatible with ATENA. So, you can go to the following address to model different types and shapes of FRP:

data-Materials-Solid Concrete- Reinforced Concrete.

If you go as above a window will be open with 7 tabs. You can define your FRPs here. The mechanical properties of FRPs can be defined in this section. For instance, the direction, the elastic modulus,the elongation of FRPs and other parameters such as Poisson ratio can be defined using these tabs. I hope the information would be handy and useful.

Good question.

Anchorage can be modelled only if you consider bond slip interface elements along reinforcements; otherwise full bond is supposed and anchorage is therefore not necessary. Please contact me in private if you need extra explanation.

I agree with A S Kaddour .

Hi MS Haifa Mahdi Saleh

I hope following files could helpful for you.

The pushover curves (base shear- drift curves) depend on a lot of input parameters such as dimensions of the section and member, sizes of reinforcements, characteristic strength of concrete, yield strength of steel, Poison ratio, shear and elasticity modulus,.....Therefore I recommend you, first to check the inputs, if they are correctly implemented you may do a parametric study and by changing the parameters one-by-one you will observe the variation and you can judge that your application was right or wrong, your expectation was a real expectation or not.

I wish you the best of luck.

Good explanation @Victor

The following links are for papers that may contain useful information for you:

https://www.sciencedirect.com/science/article/pii/S1110016818302060

Suraksha Sharma,

by the diffusion coefficients you describe the element transport, but to calculate concentration there is more needed. Consider for example the case of heat diffusion. You describe the heat transfer not only by the heat conductivity but also by the density and the heat capacity, turning this physical quantities into the so called thermal diffusivity. This you need, because the different materials or even more simple one material in its two phases, e.g. solid and liquid iron, have different heat capacities.This says simply, you can store more energy or more of element in the one material, than in the other! The second Fick's law you are using in COMSOL models the transport of the element but only if you have homogeneous materials. In such a case the concentration transport and distribution will depend only on the concentration gradient. The same would happen if you model heat transfer by describing the energy conservation by enthalpy. Here two practical examples for you:

1. Heat transfer: Imagine you have two materials with different heat capacities sharing a boundary with different temperatures on both sides, like if you heat them up and put them together. If you describe the heat transfer in homogeneous materials by using the enthalpy you will have no heat transfer. Why so? Just because you will have no enthalpy gradient (enthalpy = heat capacity*temperature). From this equation you see, you can have a small heat capacity value multiplied by a high temperature on the one side of the boundary and a bigger heat capacity value multiplied by a small temperature value on the other side of the boundary. Hence, there will be no enthalpy gradient and you will conclude that you have no energy/heat flow. But if you describe the heat transfer for inhomogeneous materials, which should be done using the potential, in this particular case the potential is the temperature, you will end with different temperature values on both sides of the boundary, resulting in a temperature gradient leading to a heat/energy flow.

2. Concentration: Imagine you have a glass half full with butter and water. And you have the same concentration of let's say sugar in both the butter and the water. This results in concentration gradient on the joint boundary equal to zero. So, one would conclude, there will be no diffusion. But this is wrong, very wrong and would be correct only in the case of homogeneous materials, which butter and water obviously are not! So what happens in such a case? You need to use another equation, which uses the potential to describe the diffusion, in this example this would be the chemical potential. Similarly to the heat transfer (enthalpy = heat capacity*temperature, where temperature is the potential), (concentration = solubility*chemical potential). From here you see, heat capacity plays the role of solubility and concentration this of enthalpy. Because you have different solubilities in butter and water, just like different heat capacities in the case of heat diffusion, you can save more sugar in the water, than in the butter. This means that by using concentration to describe the process, you end up with small solubility and a high potential value on the one side of the boundary and a higher solubility and a small potential value on the other side of the boundary. Just like in heat diffusion, th

First of all, you need to know at which state your material exists at the operating temperature, does it overcome any phase transition (which is usually accompanied with changes in physical properties). If you know all that, you need do chose an appropriate material with lowest chemical reactivity, lowest viscosity at the operating temperature and lowest tendency to overcome a phase transition prior to in-mold hardening.

check the below link;

https://numericalarchive.com/shop?olsPage=products%2Ffinite-element-analysis-of-reinforced-concrete-slab-strengthened-by-frp

make sure that the BC in Z direction is negative 10 mm.

check U displacement in z direction Mohammed Shehadah

The slip can be controlled through the CZM properties in the engineering data "Tangential Slip at completion of debonding" . On the other hand the tangential and normal stiffness can be controlled directly through commands under the specified contact pairs (Concrete & Steel in your case) as follows

RMODIFCID,3,-500 !normal stiffness "Check your unit System"

RMODIF,CID,12,-500 !Tangential stiffness "Check your unit System"

Is there any connection between the concrete and the FRP sheets ?

i think the material doesn't define well. You must make a bonding material between concrete and FRP sheet. By the way, sometimes the increasing of FRP layers doesn't effect the load capacity.

Hi Meysam Khodaei

Thank you very much for the reply! I will contact you if there's any further question.