Hi sir, in your model , you have modeled composite layer as homogenized material. how to model matrix, fibres and matrix-fibre interfaces to model a composite layer

hi sanan could you please explain, how i might go about doing a steady state thermal tensile simulation, lets say 600°c.

Hi Sanan.....I just saw your video and learnt a lot...thank you.....please tell me if I am using the stress in MPa, what are the values of the fracture energies, with respect to this video. Here, you use 1986.5. Regards

Hi Sanan. Great work.. I am having a problem for a composite crack modeling using XFEM .do you have any tutorial or video that can be shared?Thank you.

sir thank u for the video sir iam working on Impact for FML, after giving all the relavent data when i go for job.. iam not getting error but indentor is not in motion even though i have contact contraints and interaction between the layers

Dear Sir I have an issue with composite tube subhected to dynamic bending. the predicted force-displacement load is less than experimentla by a round 50% would you be able to help? Samer

Thanks a lot for the video. It was really helpful. I am trying to model the bond slip between steel rebar and concrete. I have followed the same procdure as you have explined for the cohesive properties and the interaction. But the results are not very good. The steel seems not to transfer any stress to the surrounding concrete, and it seems as if the the cohesive action is not active. My questions is: since the steel is embedded in the concrete in my case, should i also specify the embedded constraint in Aqaqus?

@wahaajali1009

4 жыл бұрын

could you solve this problem? I am also having a similar one

sir what is the part thickness of aluminum and glass fiber in the initial part as the relative thickness of eglass epoxy is 0.5 so is it the same thickness you have provided in part model of the ABAQUS

great video sanan. can you share some thoughts on how to implement periodic boundary conditions in abaqus. Im working on repeating unit cell model...

@SanaanKhan

9 жыл бұрын

amjad Khan its very easy. As you can see on 28:00 i m trying to tabulate the amplitude values. In the same way you can formulate a periodic amplitude data. you can use Matlab to generate these values like i have done, by using sin or cos function. this will give more smooth b.c. also you can define the amplitude as periodic instead of tabular.

Hi Sanan, Could you please tell me the difference of geometric properties between L2L and M2L?

Hi, Sanan. Thanks for sharing your good work. Regarding modelling the composite pipe(let's say a very thin one 10mm with 50 layers), do you suggest that we use continuum shell to model it? In this case, we have model 50layers of composite as each one has different radius?Or do you another method to model the composite pipe? Appreciate your help.

@SanaanKhan

8 жыл бұрын

+Zhenyu Huang radius or thickness ? i think if out of plane stresses is not of much importance try using conventional shell.

Hi Sanan, Could you please tell me where you get the data for hashin model and damage evolution and do you where where I can get data fro different lamina (actually I am working on woven carbon fiber lamina I just would need something similar to my composite) thanks

@SanaanKhan

8 жыл бұрын

I have obtained most of the parameters through experiment while rest is obtained via PD soden

hello sanan tell me how to simulate abrasive wear and shock of a material. Can you help me. thank you

Hi Sanan Thank you so much for your professional video. I have a question. You have mentioned during your video that you have brought the material properties related to HASHIN damage form a paper with the name of “PSODEM” or something like this. Could you please tell me the correct name of this gay or more detail about his article title? Good luck Usof

@SanaanKhan

9 жыл бұрын

Usof Shervan P.D. Soden

Hi Sanan, great video and explanation. Truly helped. Can you explain how you calculated the value of Fracture energy? Also would there be any benefit of using a implicit model? How would the results differ?

@SanaanKhan

7 жыл бұрын

Kshitij Sonkar area under load disp curve is energy

@ksonkar

7 жыл бұрын

Sanan H Khan thanks, what about running the step as implicit?

@SanaanKhan

7 жыл бұрын

Kshitij Sonkar if your model is highly nonlinear you will face difficulty in conversing solutions

@ksonkar

7 жыл бұрын

Sanan H Khan okay. I'm facing issues with lower stain rates. You have used a very high rate. The calculations with lower rates like 0.1 per second take over an hour to calculate. Is there a way to reduce the run time.l?

@rushabhshah7748

7 жыл бұрын

Please reply to comment in your video 'Three point bend test of fibre metal laminates with cohesive surface behaviour'. It will be really helpful Thank you

hi sir sanan i apreciated your methode of calculating fracure energy which seem easy can i use it to calculate fracture energy in mode 1 and mode 2 of a cohesive zone model interface of two bonded parts?

@SanaanKhan

9 жыл бұрын

salim yagoub. :) . NO buddy. technically it will be wrong. because the method gives the fracture as a function of stress strain and characteristic element length. while the fracture energy obtained in actual experiment will be area under the load disp. curve. now the load disp. curve cannot be converted to stress strain curve for interface layer for obvious reasons unlike composite laminate/brittle material.

@SanaanKhan

9 жыл бұрын

Sanan H Khan moreover. it is not a method. its a basic geometric understanding. and it only gives the approximate value. and i think approximate is starting step of FEM !!!

can you post the models (inp) to us?

@balo700

3 жыл бұрын

I have the same question

Hi Sanan, Thank you for this grate video,It is very useful. Can you explain more how to calculate Characteristic length.If we have only stress-strain energy, how to define this length and define fracture energy. Thank you in advance. Amirreza,

@SanaanKhan

7 жыл бұрын

characterstic length =sqrt(h*h)/cos(theta). here h is your element size and theta is crack opening angle. (you can take it as 45 degree)

@amirbastani1944

7 жыл бұрын

Thank you Sanan

Sanan Is their any other procedure to model composite layup in abaqus with out using cohesive surfaces. Can I use tie constrains to combine the layers.

@SanaanKhan

9 жыл бұрын

Yes definitely it can be used. But u don't tie the layer instead you insert the cohesive elements between the layer and tie them together.

@psaibhargav

9 жыл бұрын

Sanan H Khan Thank you sanan. Is it is possible to disturb the fiber orientation in the middle of the ply to study the effect of in-plane fiber waviness.What is the logical way to model this fiber waviness.I have modeled tows and combined together using tie constrains to make a single ply, later I have modeled wavy tow in the center of the ply, the misaligned portion I fill with resin and tied them together to mock misalignment of fiber tows and resin rich area.I have used orthotropic properties & 3D Brick elements.

@SanaanKhan

9 жыл бұрын

Saibhargav Pottavarthi to obtain the in plane effect in this situation will not be possible I think. Why u are not trying it through micro mechanics approach. With single fibers of 0/90/45 etc with surrounding material as resin. RVE approach perhaps will be better I think. You will have more control over waviness.

hi sanan, i followed the tutorial and tried it step by step. unfortunately i get an error "Surface based COHESIVE BEHAVIOR cannot be used for contact pair interactions. See the surface iteraction named L2L" please can u help me i this.

@SanaanKhan

8 жыл бұрын

+Prince L brig the surfaces in general contact and no cohesive behaviour in that. use the individual property assignment for that.

@princel6819

8 жыл бұрын

+Sanan H Khan thank you very much sanan. i try it

@rushabhshah7748

7 жыл бұрын

Hi Prince, Can you please tell me about surface interaction L2L. How to choose it ?

Is geometry made by considering some ASTM standards? what are the dimensions of the geometry. i have tried a sample problem results are not showing the general trends. thank you

@SanaanKhan

7 жыл бұрын

yes... astm D7136

@lalkrishna4518

7 жыл бұрын

Thank you..

Hi sanan.. are you made the abaqus?? it seems you know everything behind the icons.. hehehe... anywhere great explanation.. great video...

hiThank you for this grate video. I am modeling a 3d tensile specimen in abaqus explicit. This model have two parts. One part has elastic state and another part has become plastic. The material is steel. In modeling of interface, I have used interaction with surfaced - based cohesive behavior. My questions is ; How can I get Cohesive behavior, damage initiation and damage evolution parameters; Cohesive behavior=(Knn,Kss,Ktt) damage initiation =Normal only,Shear-1 only,Shear-2 Only damage evaluation = normal fracture energy, 1st shear fracture energy, 2st shear fracture energy .. Thank you

@SanaanKhan

7 жыл бұрын

these properties are obtained experimental depending upon your interface material. but my experience says that even if you got it from the experiments they will not exactly represents the behavior. they are strain rate dependent. and they are usually obtained from static tests. like enf and mmb are used to obtain fracture energies. however during an impact analysis the dissipated energy is more than experiment. so logical explanations are important while choosing the values. for example consider your interface as matrix dependent ( it is eventually made from the matrix !). so your Knn=E22, (very good assumption), choose other 2 as same.( mode independent). normal opening strength will be matrix strength in tension. as the crack will open during delamination normally. choose other two as same or 1.4 times or 1.5 times ( it is seen for most of the interface exposy resin). matrix tensile energy can be chosen for normal mode. other two can be made equal or as done for the strength above. but even if you dont have the matrix tensile energy. then find it out as Gmt=0.5*Yt*emt...Yt failure strength and emt is failure strain in tension. emt=sigma22/E22. if you follow the above guidelines you assumption will be good.

@srasajjadi82

7 жыл бұрын

thanks for your answer but my model has made of steel completely and only have one material. half of model has elastic state and the other has plastic state. I don't know what properties do I consider for interface of this two halves? by the way, how can I upload a picture of my model?

@srasajjadi82

7 жыл бұрын

hi I have problem with my model. can I have your email address?

@srasajjadi82

7 жыл бұрын

hi thanks for your great modeling and educating. I have modeled above model as you said ,but it gives this error: "The ratio of deformation speed to wave speed exceeds 1.0000 in at least one element. This usually indicates an error with the model definition. Additional diagnostic information may be found in the message file." what's the cause of this error? or can i have your CAE file? this is my email address: srasajjadi82@gmail.com

Hi Sanan, Just a confirmation, do you really think do you need to specify the amplitude? I think you can just simply choose the ramp amplitude and it will do the same as you do. Dont need to make excel and matlab like that.. IMHO. Just check to clarify..

@SanaanKhan

9 жыл бұрын

Yes you are right. But I just want to ensure that the loading as slow as possible to avoid convergence issue. Moreover Ramp is not supported for Explicit analysis.

@ksonkar

7 жыл бұрын

Sanan H Khan why do we need to enter so many values? Wouldn't a tabular data ensure a linear progression?

can you please send a copy of this file

Dear Sir,, should i use these properties for the impact analysis of e-glass fibre and epoxy resin.

@SanaanKhan

5 жыл бұрын

Yes you can

@arunrajput5661

5 жыл бұрын

@@SanaanKhan Thank you so much sir for ur kind reply. i have one more small doubt, have u used these properties from any research paper or experimental data. Please send me link because i am going to publish these results after simulation therefore for reference purpose i need that paper reference or data reference. Looking forward for positive response.

@SanaanKhan

5 жыл бұрын

www.sciencedirect.com/science/article/pii/S1359836817303372

@arunrajput5661

5 жыл бұрын

@@SanaanKhan Very very thank you sir......

a question , which are the amplitude values please :)

@SanaanKhan

9 жыл бұрын

Amplitude values are on y axis.

@usannand

9 жыл бұрын

Sanan H Khan

@usannand

9 жыл бұрын

hi Shan, i have few doubts on fracture energy calculation. can you help me out.. anand.jothi@altair.com

@SanaanKhan

9 жыл бұрын

you can post your comments Anand Nand

hello sir...i need help with a particular model...can you help

@SanaanKhan

8 жыл бұрын

+Rajat Jain please post ur questions here only. others might also come in and give a handy reply.

caption? can someone add caption?

wàààw!! great thnx

Here is the link to the article :) www.sciencedirect.com/science/article/pii/S1359836817303372

may I get your email id...actually I have some doubt in my project, need your help

Check out the results kzread.info/dash/bejne/nIWjycegorKxn9I.html

@usannand

9 жыл бұрын

Sanan H Khan hi sanan, How to calculate fracture energy of each mode(fiber and matrix). i have test data FD curve for four point bending test. and i dnt have adhesive property. is there any way to calculate the energy release rate for debonding

@usannand

9 жыл бұрын

Sanan H Khan is there any coupon test to conduct the fracture energy of each mode in FEA.

@SanaanKhan

9 жыл бұрын

Anand Nand as i stated in the video, the fracture energy for each mode (fiber and matrix tensile and compressive, 4 modes right !)will be obtained from the test data (FD) obtained from that particular mode. now you know a DCB, ENF and ECT will give you mode 1,2,3 respectively FD data. similarly MMB will give you a mixed mode (1,2) fracture energy.

@SanaanKhan

9 жыл бұрын

Anand Nand i think you are confused with the definition of the two terms. fracture toughness, fracture energy, EER. all looks to be very same. here is the difference. fracture energy is the critical energy after which the crack will grow, while EER is energy per unit area and will be there in the crack from the time it was loaded and even after it has propagated. it is the energy release rate which may go up and down. fracture toughness and fracture energy are same LEFM and differs in EPFM. fracture toughness is the critical energy that that crack reaches before making two new surfaces.

@usannand

9 жыл бұрын

Sanan H KhanHi Sir, Am new to composites. please explain how to do DCB test for composites in abacus... while doing DCB test ply orientation will influence the fracture toughness? what are the ply i have to consider for DCB test. please help me

hey, i am also working on similar Mtech project that deals with delamination . Please share your email so that I can contact you regarding some problems I am facing currently.