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Great tutorial, it is very helpful for getting into COMSOL. Generally I do not really know how to get most effectively into COMSOL, so finding such videos is always a lucky event.
Thanks a lot, great tutorial. I would like to see the same tutorial for Creep and stress relaxation tests. That is, in the case of indentation processes, the applied force remains constant and the displacement is determined in case of creep, and in the case of stress relaxation, the displacement remains constant and the force is measured. It is more interesting if the indenter and the sample are made of different materials.
@@aleksandarhaber I am currently using MATLAB, and I have no experience with Comsol. Otherwise, I would be willing to share ). My intention is to learn Comsol in the near future. Anyway, thx
Helpful video. Could you please tell me how does one apply a time dependent load that is a chirp function to the edge of the plate and get an amplitude vs. frequency plot as a response to such a load?
Hi Alexander. Thank you for your shared video. I can define constant velocity values, then compute for the moving of different domains. I wonder how can I define vectorial velocity on several points through the domain. I don't want to define a constant value for the 3D domains. I want to define several velocity values on a single domain. Thank you.
Follow the approach I explained in the video and define your function describing the load in MATLAB and then import it in COMSOL as a file, and do the interpolation.
Yes, it is possible. You need to add structural mechanics and heat transfer studies to your study and then you will have a complete thermo-mechanical study.
You posted this 3yrs. It is one of the problem in my research. I planned to use variable power input from solar irradiation as heat source. Will it be possible to contact you later. Otherwise your efford is incredibly interesting
Thank you for the positive comment. Unfortunately, we do not have time and energy to answer particular questions about this project. All we can do is create these free tutorials and educate future engineers.
That is a great tutorial. I would like to ask: Could i just define somehow the variable t without certain values? For example I want to inster the waveform sinus for an AC current, for which the parameter t is needed.
Hi Lampros, First of all, thank you very much for your interest. Then, I am not sure that I completely understand your question. Can you please elaborate it a little bit more?
@@aleksandarhaber Hi Aleksandar thank you for the quick response. I want to have as an input for electric potential for example this: B+A*sin(2*pi*f*t+z). For a frequency stationary problem, the only variable here is t (time dependent problem). For this problem, can i use this expression just by defining t somehow? Or do I have to use time-stepping parameters? I hope its understandable.
@@lamprospapadopoulos9637 You can directly define electric potential as a function of time t. www.comsol.com/forum/thread/47345/Parameter-as-function-of-time-in-time-dependent-simulation Also, you can find COMSOL reserved name for certain variables and you can play with them. Read and search more about this.
Hi! Thank you for this video. I think it's very helpful. Nevertheless, I'd like to ask you what you think about the, for example, possibility of doing a ramp function and define the applied force as "Maximum Applied Force[N]" * "Ramp function(t[1/s])". I did that on a study of an aluminum hardware being loaded by a force which starts from zero until 15000N, but, from 0 [s] to 60 [s]. Is that correct? Why didn't you define your sin(wt)+kt function on COMSOL and give the applied force that instruction? Why using MATLAB? Is that necessary or it was just easier for you? I ask because I am having some linearity - non linearity problem which just bug my COMSOL when it gets to 4% on the solver, but, I realized It happens just when my force and study are time dependent, but not stationary. Thank you in advance.
Imagine a situation, where you want to import an input load from experimentally observed data. In that case, you would definitely need to import a data from the file. Also, imagine that you want to connect a MATLAB simulation module that computes something with COMSOL. All these examples illustrate the need for defining time-varying loads from files. Definitely, you can specify analytic functions directly in COMSOL. However, as I explained, this is an approach that has its limitations. A more general approach is the approach I am explaining. Best. A. Haber
@@aleksandarhaber I agree with you. In fact, my simulation is assuming a loading test using a Materials Testing Machine. I think interpolating is a much effective assumption indeed. Thank you!
Hello Alexsander, it seems damping doesn't effect on different frequencies of the structures. please correct me if I am wrong. I am simulating a CC beam and setting sinusoidal force magnitude and frequency. It is expected that in different frequency we get different amplitudes but comsol doesn't understand it. (I tried multiple damping factors)
COMSOL is able to simulate damped frequency response: th-cam.com/video/RyA0aif2wwg/w-d-xo.html You have probably incorrectly defined the problem or boundary conditions.
And you can also check this paper, I recently wrote: www.osapublishing.org/oe/fulltext.cfm?uri=oe-28-4-4726&id=426576 There is a GitHub page I created that contains the codes used in that paper.
@@aleksandarhaber I has seen this movie. It's for frequency response analysis and yes damping can be applied on that. But here for TIME DEPENDEND analysis, COMOSOL fails.
@@aleksandarhaber put a sin(t), sin(50t) or sin(100t) for the input force and amplitude of response nothing changes. Just frequency changes, according to the frequency of excitation.
Depends on how you plan to use this data. In my case, I have a load that is a function of time. I saved the data as a txt file, the first column is "time" and the second one is "load". Then you can import this data directly into COMSOL to give you the ability to interpolate this data and to include it in your simulation. If a temperature is a parameter that is included in your model and this parameter varies with time, then you should follow the same approach I did. Watch the video from 19:00, and everything is explained. Thank you for the interest. Best, A. Haber
If you need help with your professional engineering problem, or you need to develop new skills in the fields of control, signal processing, embedded systems, programming, optimization, machine learning, robotics, etc., we are here to help. We provide professional engineering services as well as tutoring and skill development services. We have more than 15 years of industry, research, and university-level teaching experience. Describe your problem and we will send you a quote for our services. The contact information is ml.mecheng@gmail.com
Amazing tutorial! Will you please advice me on how to defined a user defined force which varies as a function of structural deformation. For example, Casimir force that acts between plates of a parallel plate capacitor. Thank you once again.
You should identify what is the variable quantifying the structural deformation, and then specify that the force is a function of that variable, when defining the load.
@@aleksandarhaber Thank you for your reply! Will it be possible for you to make a tutorial video explaining this feature with some basic structural mechanics problem? That will be of great help to entire COMSOL user community.
Good day Sir, I am new to COMSOL. I want to model a point source from which Electric Field spreads out in x,y directions. I am working in 2D plane. I started of by creating a geometry with air, and then specified my point. How do I assign electric field to my point? Any help would be greatly appreciated. Regards
Hi, I am working on electrostatically actuated cantilever. I am trying to get the point where the cantilever fall flat on the substrate. However, as it is beyond pull-in (buckling type run off), I am unable to get that. Is there any way to simulate the state where cantilever fall flat on the substrate? Thank you in advance.
Hi Kamrul, I am not sure that I understand your problem completely. Have you looked into the COMSOL tutorial: www.comsol.com/model/electrostatically-actuated-cantilever-444 On the other hand, you also have contact modeling tools in the structural mechanics toolbox: www.comsol.com/support/knowledgebase/1102 If I remember correctly, it is possible to detect contacts between two surfaces using contact modeling. I am not 100% sure. Maybe there is an easy way to solve your problem. However, I do not understand your problem completely.
@@aleksandarhaber Thank you. Yes I have checked the model "electrostatically actuated cantilever". In that model, pull in voltage is calculated by basing on the divergence of the solution. However, I am actually interested in the final geometry when the beam lands on the bottom electrode due to electrostatic force.
@@md.kamrulhasan3220 You need to find out voltage just before the occurrence of pull-in by performing simulation at different voltage step. User that critical voltage to get critical deformation shape.
sir i am working on a model in which i am having a cube and i have input the material property for structural mechanics. But what i want is i want to role half of that sheet so that bottom of the sheet touch the middle of the sheet and now i want to study stress and strain on that whole sheet. Please help me sir by replying me i am looking for this from 2 months ago. Note : you can consider that geometry as sheet or block.
Hello, I do not understand your question properly. It seems to me that the only problem is to define the geometry of the problem. You can define the geometry in 2D and then you can extrude it to obtain the shape you are describing. On the other hand, if you want to prestress the problem, such that the rolling causes elastic stresses, you can also do that in COMSOL. However, I am not exactly sure how to do that. Try to search for prestressed problems for example. Sorry that I cannot help more at this point, I am very busy. I can only make these simple tutorials for new COMSOL users and for my students.
@@aleksandarhaber sir, what i wanna say is that i am curving a sheet which is elastic in nature and i wana study stress and strain this is my question sir
@@msreeabeyvignesh8254 Hi, I am not able to look into this problem at this point. However, I think that your problem is interesting, and I might look into it in the near future. If you find the solution, please let me know. Thank you, Aleksandar
Hi Arun, here is what I have found online: digitalcommons.ric.edu/cgi/viewcontent.cgi?article=1173&context=honors_projects In this thesis, the author is using COMSOL to model the triboelectric nanogenerator. You can also look here for additional references: www.researchgate.net/post/Simulation_of_Triboelectric_Effect_in_COMSOL_Multiphysics Best, Aleksandar Haber
@@aleksandarhaber thanks for you reply... actually I have read this paper..but they haven't measured output voltage or current here.. actually I need those measurements where I can measure induced potential at electrod due to the surface charge at polymer.
hello sir. Can I help you in comsol to design three phase squirrel cage induction motor ? since i am master degree and i need a person who help me in this program.
I have a few doubts regarding FSI simulations. If its possible for you to help me, please provide an email so that I could reach you and explain my problem. Thank you in advance.
It takes a significant amount of time and energy to create these free video tutorials. You can support my efforts in this way:
- Buy me a Coffee: www.buymeacoffee.com/AleksandarHaber
- PayPal: www.paypal.me/AleksandarHaber
- Patreon: www.patreon.com/user?u=32080176&fan_landing=true
- You Can also press the Thanks TH-cam Dollar button
Muchas Gracias. El tutorial está magnífico. Saludos desde la Universidad de México
Thank you!
I had been stuck for a week on this. Thanks very much.
Thank you for the comment and interest! Best, Aleksandar Haber
Great tutorial, it is very helpful for getting into COMSOL. Generally I do not really know how to get most effectively into COMSOL, so finding such videos is always a lucky event.
Thank you very much Yuefei2. I am glad that I can help!
Especially learned how to add point load to solve my problem: displacement at different force
Good to hear
Excellent Tutorial!
Thanks.
Thank you!
Thank you so much for this. It's a great learning resource!
Thank you Bhanu! Check also other videos and tutorials, there are plenty of them.
This video is very helpful. Thanks for sharing!
Thank you!
Cool, perfect tutorial👍👍👍
Thank you
Thanks!!! You saved my life!
Glad I could help!
Thanks a lot, great tutorial.
I would like to see the same tutorial for Creep and stress relaxation tests. That is, in the case of indentation processes, the applied force remains constant and the displacement is determined in case of creep, and in the case of stress relaxation, the displacement remains constant and the force is measured. It is more interesting if the indenter and the sample are made of different materials.
Why don't you try to make such a tutorial
@@aleksandarhaber I am currently using MATLAB, and I have no experience with Comsol. Otherwise, I would be willing to share ). My intention is to learn Comsol in the near future. Anyway, thx
@@etibarmikayilov4891 Learn COMSOL, it is a very useful engineering tool.
Thanks for the amazing example!
Thank you!
This video is very helpful!
Thank you for the positive comment! Best, A. Haber
Helpful video. Could you please tell me how does one apply a time dependent load that is a chirp function to the edge of the plate and get an amplitude vs. frequency plot as a response to such a load?
Can you apply the approach that I explained in the video?
Hi Alexander. Thank you for your shared video. I can define constant velocity values, then compute for the moving of different domains. I wonder how can I define vectorial velocity on several points through the domain. I don't want to define a constant value for the 3D domains. I want to define several velocity values on a single domain. Thank you.
Use LiveLink for MATLAB interface to do something like that. I have several videos on how to start with LiveLink for the MATLAB interface.
@@aleksandarhaber Thanks for your fast response. I am gonna have a check it out.
@@scientistturk Thank you for your interest.
Thanks.
I had forgotten the (t) on "int1(t)"
Good, I hope that this video solves your problem.
For more videos and tutorials on COMSOL and mechatronics see www.aleksandarhaber.com
great job Dr ...if possible advise me on how can I do a periodic load at a specific time, please. sincerely
Follow the approach I explained in the video and define your function describing the load in MATLAB and then import it in COMSOL as a file, and do the interpolation.
dear Aleksandar Haber
is it possible to marriage between load and thermal stress in one geometry?
Yes, it is possible. You need to add structural mechanics and heat transfer studies to your study and then you will have a complete thermo-mechanical study.
You posted this 3yrs. It is one of the problem in my research. I planned to use variable power input from solar irradiation as heat source. Will it be possible to contact you later. Otherwise your efford is incredibly interesting
Thank you for the positive comment. Unfortunately, we do not have time and energy to answer particular questions about this project. All we can do is create these free tutorials and educate future engineers.
That is a great tutorial. I would like to ask: Could i just define somehow the variable t without certain values? For example I want to inster the waveform sinus for an AC current, for which the parameter t is needed.
Hi Lampros,
First of all, thank you very much for your interest. Then, I am not sure that I completely understand your question. Can you please elaborate it a little bit more?
@@aleksandarhaber Hi Aleksandar thank you for the quick response. I want to have as an input for electric potential for example this: B+A*sin(2*pi*f*t+z). For a frequency stationary problem, the only variable here is t (time dependent problem). For this problem, can i use this expression just by defining t somehow? Or do I have to use time-stepping parameters? I hope its understandable.
@@lamprospapadopoulos9637 You can directly define electric potential as a function of time t.
www.comsol.com/forum/thread/47345/Parameter-as-function-of-time-in-time-dependent-simulation
Also, you can find COMSOL reserved name for certain variables and you can play with them. Read and search more about this.
Hi! Thank you for this video. I think it's very helpful. Nevertheless, I'd like to ask you what you think about the, for example, possibility of doing a ramp function and define the applied force as "Maximum Applied Force[N]" * "Ramp function(t[1/s])".
I did that on a study of an aluminum hardware being loaded by a force which starts from zero until 15000N, but, from 0 [s] to 60 [s]. Is that correct?
Why didn't you define your sin(wt)+kt function on COMSOL and give the applied force that instruction? Why using MATLAB? Is that necessary or it was just easier for you?
I ask because I am having some linearity - non linearity problem which just bug my COMSOL when it gets to 4% on the solver, but, I realized It happens just when my force and study are time dependent, but not stationary.
Thank you in advance.
Imagine a situation, where you want to import an input load from experimentally observed data. In that case, you would definitely need to import a data from the file. Also, imagine that you want to connect a MATLAB simulation module that computes something with COMSOL. All these examples illustrate the need for defining time-varying loads from files. Definitely, you can specify analytic functions directly in COMSOL. However, as I explained, this is an approach that has its limitations. A more general approach is the approach I am explaining. Best. A. Haber
@@aleksandarhaber I agree with you. In fact, my simulation is assuming a loading test using a Materials Testing Machine. I think interpolating is a much effective assumption indeed. Thank you!
@@baterosinser nice application
Hello Alexsander, it seems damping doesn't effect on different frequencies of the structures. please correct me if I am wrong. I am simulating a CC beam and setting sinusoidal force magnitude and frequency. It is expected that in different frequency we get different amplitudes but comsol doesn't understand it. (I tried multiple damping factors)
COMSOL is able to simulate damped frequency response:
th-cam.com/video/RyA0aif2wwg/w-d-xo.html
You have probably incorrectly defined the problem or boundary conditions.
And you can also check this paper, I recently wrote: www.osapublishing.org/oe/fulltext.cfm?uri=oe-28-4-4726&id=426576
There is a GitHub page I created that contains the codes used in that paper.
@@aleksandarhaber I has seen this movie. It's for frequency response analysis and yes damping can be applied on that. But here for TIME DEPENDEND analysis, COMOSOL fails.
@@aleksandarhaber put a sin(t), sin(50t) or sin(100t) for the input force and amplitude of response nothing changes. Just frequency changes, according to the frequency of excitation.
hello sir, if i have excel data which is time and temperature of every 30 min a day, did i have to import it as two parameters?
Depends on how you plan to use this data. In my case, I have a load that is a function of time. I saved the data as a txt file, the first column is "time" and the second one is "load". Then you can import this data directly into COMSOL to give you the ability to interpolate this data and to include it in your simulation. If a temperature is a parameter that is included in your model and this parameter varies with time, then you should follow the same approach I did. Watch the video from 19:00, and everything is explained. Thank you for the interest. Best, A. Haber
@@aleksandarhaber thankyou so much sir, you’ve been very helpful for my progress!
@@muhdkhaidir2707 Thank you for the kind words
If you need help with your professional engineering problem, or you need to develop new skills in the fields of control, signal processing, embedded systems, programming, optimization, machine learning, robotics, etc., we are here to help. We provide professional engineering services as well as tutoring and skill development services. We have more than 15 years of industry, research, and university-level teaching experience. Describe your problem and we will send you a quote for our services. The contact information is ml.mecheng@gmail.com
Amazing tutorial! Will you please advice me on how to defined a user defined force which varies as a function of structural deformation. For example, Casimir force that acts between plates of a parallel plate capacitor. Thank you once again.
You should identify what is the variable quantifying the structural deformation, and then specify that the force is a function of that variable, when defining the load.
@@aleksandarhaber Thank you for your reply! Will it be possible for you to make a tutorial video explaining this feature with some basic structural mechanics problem? That will be of great help to entire COMSOL user community.
@@kdSU30 Hi, Kedar, currently I do not have time for that, but it is definitely a good idea.
Hi, how can i apply contact between membrane and solid?
That is something that you need to investigate. I cannot give an answer without doing some research on this topic.
@@aleksandarhaber circular memberane with fixed outer edges and central disk mass. 2 physics: solid mechanics and membrane.
@@erfanasgari4398 Good to know. Thank you!
Good day Sir, I am new to COMSOL. I want to model a point source from which Electric Field spreads out in x,y directions. I am working in 2D plane.
I started of by creating a geometry with air, and then specified my point. How do I assign electric field to my point?
Any help would be greatly appreciated.
Regards
Hi, I am not able to help you simply because I do not have time. Your problem requires some independent study and effort.
Hi,
I am working on electrostatically actuated cantilever. I am trying to get the point where the cantilever fall flat on the substrate. However, as it is beyond pull-in (buckling type run off), I am unable to get that. Is there any way to simulate the state where cantilever fall flat on the substrate? Thank you in advance.
Hi Kamrul, I am not sure that I understand your problem completely. Have you looked into the COMSOL tutorial:
www.comsol.com/model/electrostatically-actuated-cantilever-444
On the other hand, you also have contact modeling tools in the structural mechanics toolbox:
www.comsol.com/support/knowledgebase/1102
If I remember correctly, it is possible to detect contacts between two surfaces using contact modeling. I am not 100% sure. Maybe there is an easy way to solve your problem. However, I do not understand your problem completely.
@@aleksandarhaber Thank you. Yes I have checked the model "electrostatically actuated cantilever". In that model, pull in voltage is calculated by basing on the divergence of the solution. However, I am actually interested in the final geometry when the beam lands on the bottom electrode due to electrostatic force.
@@md.kamrulhasan3220 You need to find out voltage just before the occurrence of pull-in by performing simulation at different voltage step. User that critical voltage to get critical deformation shape.
sir i am working on a model in which i am having a cube and i have input the material property for structural mechanics. But what i want is i want to role half of that sheet so that bottom of the sheet touch the middle of the sheet and now i want to study stress and strain on that whole sheet. Please help me sir by replying me i am looking for this from 2 months ago. Note : you can consider that geometry as sheet or block.
Hello, I do not understand your question properly. It seems to me that the only problem is to define the geometry of the problem. You can define the geometry in 2D and then you can extrude it to obtain the shape you are describing. On the other hand, if you want to prestress the problem, such that the rolling causes elastic stresses, you can also do that in COMSOL. However, I am not exactly sure how to do that. Try to search for prestressed problems for example. Sorry that I cannot help more at this point, I am very busy. I can only make these simple tutorials for new COMSOL users and for my students.
@@aleksandarhaber thanks for your reply sir
@@aleksandarhaber sir, what i wanna say is that i am curving a sheet which is elastic in nature and i wana study stress and strain this is my question sir
@@msreeabeyvignesh8254 Hi, I am not able to look into this problem at this point. However, I think that your problem is interesting, and I might look into it in the near future. If you find the solution, please let me know. Thank you, Aleksandar
Hi,
I am working with Triboelectric nanogenerator so trying to simulate that model in comsol. can you please help me ?
Hi Arun, here is what I have found online:
digitalcommons.ric.edu/cgi/viewcontent.cgi?article=1173&context=honors_projects
In this thesis, the author is using COMSOL to model the triboelectric nanogenerator.
You can also look here for additional references:
www.researchgate.net/post/Simulation_of_Triboelectric_Effect_in_COMSOL_Multiphysics
Best,
Aleksandar Haber
@@aleksandarhaber thanks for you reply... actually I have read this paper..but they haven't measured output voltage or current here.. actually I need those measurements where I can measure induced potential at electrod due to the surface charge at polymer.
@@arunmondal2358 I am not an expert in that field, and I am sorry that I cannot help you more. Best Regards, Aleksandar Haber
hello sir.
Can I help you in comsol to design three phase squirrel cage induction motor ?
since i am master degree and i need a person who help me in this program.
Hello Ali, I do not have enough time to help you. I am really busy these days and in general. Sorry that I cannot help more at this point.
I have a few doubts regarding FSI simulations. If its possible for you to help me, please provide an email so that I could reach you and explain my problem. Thank you in advance.
Hi Harkomal, I am very busy these days. I am not able to help you more than posting these videos online. Sorry for that.
👏👏👏👏
Thank you!