Thank you Ameen. Very useful things, thank you very much for your tutorials. Especially for complex materials such as cohesive material maps. I will be incredibly grateful and happy for you if your channel develops. There are few people like you, you need to be appreciated.
Thanks again Mr. Ameen Topa. I've been learning about explicit dynamics for nearly 2 months now under my own initiative. I'm sure its going to be beneficial for my addditional skillset. I came from your LinkedIn by the way. :)
Hey Ameen, thanks for your videos in the first place ! They‘re very informative and a big help learning LS-Dyna. My problem is that after following your instructions step by step i can‘t solve it with LS-Run. There‘s an error occuring (Error termination). Van you please help me ? Thanks in advance !
Hello Ameen, i got couple of questions for you. 1. bird strike usually severly damages the balde of aircraft. so why did you consider the blade as rigid. as well as the final results dont show any damaged caused to the blade. 2. the thickness of the blade is not constant. it varies from leading edge to the trailing edge. how can i introduce the variation of thickness in the Section properties.
Hi, Usama, 1. Actually, I don't have a background in Aerospace engineering. I don't know what happens in a real bird strike. This tutorial is only to show the example of how to model a soft part with SPH. Yes, you can change the blade and make it deformable. 2. Yes, you are correct. In this example, I intentionally overlooked this variation for simplification. To model the change in the thickness, you need to mesh it as solid part, NOT as a shell. You Solid Mesh tool instead of Auto Mesher.
Thanks for tutorial. How do I learn modelling as you are doing? Like which BCs or which materials I use etc. etc.? I am just a fresh graduate trying to learn LS Dyna. How can I learn modelling skills ?!
Practice and redo the tutorials in LSDYNA BASIC TUTORIALS playlist. It goes without saying, you need to have a strong foundation in engineering topics such as strength of materials, and good understanding of physics.
@@AmeenTopa I properly field up all the parameters needed for the simulation, the sph also have density but it still passing through the blade. it's kinda weird.
@@morlax1875 check the material properties of the propeller, the contact definition, and that you have defined the node set correctly. This video is almost five years ago. Other people has manage to do it. So, it means the video is fine. You just missed something
Use the double precision solver, and make sure the node set is defined properly in the contact. The density of the sph should be set before you create the sph particles. The thickness of the blades should be set correctly. Mesh size of the blades should be similar to the one in the video. I think that's all. There is a another tutorial on Bird strike. Please watch that as well.
Hi Ameen, thank you for your nice videos. I am doing bird strike analysis against rigid flat plate. I want to take pressure values form middle of plate but pressure reading shows zero. When I define plate material as 24 piecewise linear plasticity, I can take pressure data nonzero but the values are different than study I am trying to validate. Also when I change thickness of plate, pressure changes. How can I look pressure data from middle of RIGID plate(MAT_RIGID)?
Thank you Ameen for the informative tutorial. My question is based on the concept of generating the mesh of the fin surface. I have two surfaces in line. it means; First I have drawn an "L" shaped surface and then made it "U". It is done because "L" shape has shell thickness different from the line (used to make it U shaped). My question is whether I need to do something to make it one assembly or it will automatically act as one entity.
As long as the nodes of the L and the U shapes are the same nodes. Then there is no problem. You can use "duplicate node" option to ensure there. If I were you, after I generate the L shape, I will use: element generation, shell, then edge drag.
Sir, I have a model on LS-Dyna where I am supposed to use different combinations of parameters. However, after making changes to the parent model and running the simulation on LS Run, I cannot put multiple simulations on LS-Run at the same time. The problem that shows up is LS-Dyna file already exists in the directory. Can you help me in running multiple simulations at the same time by making different changes everytime?
Thank you for your videos. They are a great help in learning LS-DYNA. Its just that I am unable to visualize the stress and strain results. Its showing 0 stress and 0 strain, thus no variation is denoted. Do I have to do something else to get them?
Hi dear Ameen, Do you have a video showing how to input both x and y angular acceleration to a rigid body? if not can you instruct me how to do so? Thanks
Hi there, Do you mean the body is rotating around 2 axes at the same time? I have tried this a long time ago but it didn't work well. I don't remember if I managed to do it or not.
Yeah it is, Actually I want to simulate traumatic brain injury in car crash tests and in real accidents we have angular acceleration on 2 axes or even all the 3 axes. Does it make sense if I write 111001 in CON2 *MAT_RIGID and create 2 *BOUNDARY_PRESCRIBED_MOTION_RIGID_LOCAL IDS? @@AmeenTopa
@@sulthanraffi3738 I think this was already discussed in one of the other comments. Please check the comments of this video and let me know if you don't find it.
@@sulthanraffi3738 first of all, make sure that the material properties are exactly as in this video. When you create the SPH, make sure the density is set correctly.. Lastly, double check the contact definition (CONTACT AUTOMATIC NODES TO SURFACE)
Hi! Thanks for ur really helpfull video, could I ask you if there is a way to rotate the propeller? To show the impact from the front? Thanks in advance!
Hello Ameen, I just wanted to see deformations on the blades so, I have changed the material from rigid to 24 piecewise linear plasticity. so I had to change the prescribed motion rigid to prescribed motion set. but after solution, i saw that the blades didn't rotate even i didn't add constraint. so can you explain me how to change material to make it deformable?
prescribed motion rigid works only ridid parts. since you made it deformable it will won't work. You may use prescribed motion set, on a set of nodes which is in the inner periphery of the blades.
Hi Ameen. I am trying to do a hypervelocity impact simulation using impedance graded shield materials and I need to tie SPH areas to each other. I was wondering if you knew of a method to do this? I want to tie adjacent layers of SPH material together and can't seem to find a contact that would work. Thanks!
Hi Ameen and thank you for your videos. I followed the tutorial until the 24th minute without problems. In the 24 minute you clicked the Settings button in the post menu but unfortunately I do not have this button on my computer (4.6 version). Do you know how i can get to the display settings without this button or alternatively add this button?
Ameen Sir, It will be great if you could enlighten us with few solved examples of ALE and multi material ALE based problems. I am working on TNT detonation based problem. The problem can be stated as follows: Effect of TNT explosion is to be determined on dummy, air and soil. TNT is burried in soil . Dummy is laying over sand. It will be great if you can help. Best regards.
hello i followed your sph and my blade is not blade but plate, al2024t3. My problem is that my sph bird is not broken. It remains sphere and my plate is broken. What is the problem..?
@@AmeenTopa I changed sph density more smaller, and now termination time is stopped.. analysis is still working but termination time is still 1.1264e-1 . And when i see d3plot, it ends before contact to the plate.
Hi Yousaf, from my understanding to your statement, it seems that your request is very basic. I believe if you follow all my tutorials, you will be able to do it. :D
@@AmeenTopa thanks for your reply but I am facing problem for getting Blast wave as shown in the link storage.ansys.com/video/animations/pressure-in-barrel-and-silencer.mp4 Here they have coupled Euler and Lagrangian solver, but I am not able to getting the shock pattern.
Hey iam in beginning phase of ls dyna do you help me to know how to add composite materails property into ls dyna softarwe,or else please send me a video which incloude a fathoming of composite material when it is utilized to apply stack. stack affect
Hey, LS Dyna is a very capable software and can do simulation of lots of things. Since you are still in beginner, I advise you first to grasp the basics of this software, how to simulate with normal material like metals, polymers...then you can advance to composite materials. You cannot rush things, but you need to learn the basics first.
ya sir however my project of M.tech depends on composite materials, i,e contributing of composite materials for ballastic effect and examination of that materials utilizing ls dyna the disappointment rates et cetera that is the reason iam making little rush.
Hi ! I'm learning the software LS DYNA, and I don't understand something : can you explain the difference between doing an object (here the bird) with nodes and with elements with mesh ? I'm watching all your tutorials (thank you for that by the way) and previously you didn't use nodes to create objects. The question is why ? Thank you for your answer.
Hi. When the object (we call it part in LS DYNA) is expected to severely deform in the simulation, it is better not to model it with meshed elements. The distortion of the elements will be severe and hence errors may occur while solving the problem.
Hi, if you follow all my tutorials, you will already be able to do the turning simulation. In this video, I showed how to impose rotational move. The same way, you can do the translational movement of the specimen. The only extra thing you need to know is that you need to make the specimen with SPH particles.
We apply load usually when we want to find the stress due to some external force. To apply movement or rotation, we used PRESCRIBED MOTION or INITIAL VELOCITY.
after using(RUN) ls manger solver or ansys mechanical APDL launcher Solver,i am not be able to do binary 3D Plot,it is not showing when i open that file in ls dyna.why is it so?while same process i followed which u gave in this video.
I don't understand what you mean. If you follow my instructions, the solver will produce d3plot files. These files, you open then is ls prepost. Check my first tutorial for more details.
Thank you Ameen. Very useful things, thank you very much for your tutorials. Especially for complex materials such as cohesive material maps. I will be incredibly grateful and happy for you if your channel develops. There are few people like you, you need to be appreciated.
You are welcome and thanks for your support. I try my best to give some time to this channel, however, sometimes life happens. 😅
Thanks again Mr. Ameen Topa. I've been learning about explicit dynamics for nearly 2 months now under my own initiative. I'm sure its going to be beneficial for my addditional skillset.
I came from your LinkedIn by the way. :)
All the best!
Hey Ameen, thanks for your videos in the first place ! They‘re very informative and a big help learning LS-Dyna.
My problem is that after following your instructions step by step i can‘t solve it with LS-Run. There‘s an error occuring (Error termination).
Van you please help me ? Thanks in advance !
can you tell me what is the error?
Sometimes, if you put space in the name of the file, or the directory, an error will happen.
Hello Ameen, i got couple of questions for you.
1. bird strike usually severly damages the balde of aircraft. so why did you consider the blade as rigid. as well as the final results dont show any damaged caused to the blade.
2. the thickness of the blade is not constant. it varies from leading edge to the trailing edge. how can i introduce the variation of thickness in the Section properties.
Hi, Usama,
1. Actually, I don't have a background in Aerospace engineering. I don't know what happens in a real bird strike. This tutorial is only to show the example of how to model a soft part with SPH. Yes, you can change the blade and make it deformable.
2. Yes, you are correct. In this example, I intentionally overlooked this variation for simplification. To model the change in the thickness, you need to mesh it as solid part, NOT as a shell. You Solid Mesh tool instead of Auto Mesher.
thanks a bunch
Thanks for tutorial. How do I learn modelling as you are doing? Like which BCs or which materials I use etc. etc.? I am just a fresh graduate trying to learn LS Dyna. How can I learn modelling skills ?!
Practice and redo the tutorials in LSDYNA BASIC TUTORIALS playlist.
It goes without saying, you need to have a strong foundation in engineering topics such as strength of materials, and good understanding of physics.
@@AmeenTopa Thanks bro.
hi ameen,
I followed all your instructions in this tutorial but in my case the nodes just passed through the blade, I don't know what i did wrong.
I think when you make the SPH, you forgot to put the density of the material.
@@AmeenTopa I properly field up all the parameters needed for the simulation, the sph also have density but it still passing through the blade. it's kinda weird.
@@morlax1875 check the material properties of the propeller, the contact definition, and that you have defined the node set correctly.
This video is almost five years ago. Other people has manage to do it. So, it means the video is fine. You just missed something
Did you ever figure out the solution? I am having the same issue and I re-did the entire tutorial 3 times not skipping a step.
Use the double precision solver, and make sure the node set is defined properly in the contact.
The density of the sph should be set before you create the sph particles.
The thickness of the blades should be set correctly.
Mesh size of the blades should be similar to the one in the video.
I think that's all.
There is a another tutorial on Bird strike. Please watch that as well.
Excellent work friend. Thanks very much for sharing your work.
Many thanks! Please help my channel grow ( = more subscribers) so I can post tutorials more frequently! Feel free to share my channel hehe :D
Hi Ameen, thank you for your nice videos.
I am doing bird strike analysis against rigid flat plate. I want to take pressure values form middle of plate but pressure reading shows zero. When I define plate material as 24 piecewise linear plasticity, I can take pressure data nonzero but the values are different than study I am trying to validate. Also when I change thickness of plate, pressure changes.
How can I look pressure data from middle of RIGID plate(MAT_RIGID)?
Pressure equals to force over area. You can get the forces from RCFOR then divide by the plate area. I hope this helps.
Thank you Ameen for the informative tutorial. My question is based on the concept of generating the mesh of the fin surface. I have two surfaces in line. it means; First I have drawn an "L" shaped surface and then made it "U". It is done because "L" shape has shell thickness different from the line (used to make it U shaped). My question is whether I need to do something to make it one assembly or it will automatically act as one entity.
As long as the nodes of the L and the U shapes are the same nodes. Then there is no problem. You can use "duplicate node" option to ensure there.
If I were you, after I generate the L shape, I will use: element generation, shell, then edge drag.
Thank you very much, Sir, for your reply. Best Regards
Sir, I have a model on LS-Dyna where I am supposed to use different combinations of parameters. However, after making changes to the parent model and running the simulation on LS Run, I cannot put multiple simulations on LS-Run at the same time. The problem that shows up is LS-Dyna file already exists in the directory. Can you help me in running multiple simulations at the same time by making different changes everytime?
You may want to put each k file in a different solver.
@@AmeenTopa What exactly do you mean by solver over here Sir
Thank you for your videos. They are a great help in learning LS-DYNA.
Its just that I am unable to visualize the stress and strain results. Its showing 0 stress and 0 strain, thus no variation is denoted. Do I have to do something else to get them?
Do you see deformation in the propeller? Make sure the interaction (contact) works between the bird and the propeller.
How do I ensure that?
@@AmeenTopaI am unable to see the deformation. How do I check the contact between the propeller and the bird?
@@sam2215 did you miss the part in the video where I defined the contact card?
@@AmeenTopa I rechecked it, but I am still unable to see the deformation in the propeller
Hi dear Ameen,
Do you have a video showing how to input both x and y angular acceleration to a rigid body?
if not can you instruct me how to do so?
Thanks
Hi there,
Do you mean the body is rotating around 2 axes at the same time? I have tried this a long time ago but it didn't work well. I don't remember if I managed to do it or not.
Yeah it is,
Actually I want to simulate traumatic brain injury in car crash tests and in real accidents we have angular acceleration on 2 axes or even all the 3 axes.
Does it make sense if I write 111001 in CON2 *MAT_RIGID and create 2 *BOUNDARY_PRESCRIBED_MOTION_RIGID_LOCAL IDS?
@@AmeenTopa
Hello, i would like to ask. in my simulation the "bird" only goes through the blade and did not create an impact effect, how can i fix that?
@@sulthanraffi3738 I think this was already discussed in one of the other comments. Please check the comments of this video and let me know if you don't find it.
@@AmeenTopa hello i cant quite find it, i still have the problem can you help?
@@sulthanraffi3738 first of all, make sure that the material properties are exactly as in this video.
When you create the SPH, make sure the density is set correctly..
Lastly, double check the contact definition (CONTACT AUTOMATIC NODES TO SURFACE)
Hi! Thanks for ur really helpfull video, could I ask you if there is a way to rotate the propeller? To show the impact from the front? Thanks in advance!
Check out my second bird-strike tutorial.
Hello Ameen,
I just wanted to see deformations on the blades so, I have changed the material from rigid to 24 piecewise linear plasticity. so I had to change the prescribed motion rigid to prescribed motion set. but after solution, i saw that the blades didn't rotate even i didn't add constraint. so can you explain me how to change material to make it deformable?
prescribed motion rigid works only ridid parts. since you made it deformable it will won't work. You may use prescribed motion set, on a set of nodes which is in the inner periphery of the blades.
Hi Ameen. I am trying to do a hypervelocity impact simulation using impedance graded shield materials and I need to tie SPH areas to each other. I was wondering if you knew of a method to do this? I want to tie adjacent layers of SPH material together and can't seem to find a contact that would work.
Thanks!
I never seen anything similar done before. But you can try to check Constrained Tiebreak or Contact Tiebreak.
@@AmeenTopa okay i will try that. Thanks
Hey Ameen,can this be done using LS-Dyna toolbox in ANSYS Workbench?
Yes, ANSYS LS-DYNA can be used to model a bird strike event. But the steps might be different because the interface is different
@@AmeenTopa I tried using lsprepost but I am getting time step error probaby because i'm trying to model 5km/s impact on a plate.
You can try reduce the timestep scale factor and use SPH for both projectile and target.
Hi Ameen and thank you for your videos.
I followed the tutorial until the 24th minute without problems. In the 24 minute you clicked the Settings button in the post menu but unfortunately I do not have this button on my computer (4.6 version). Do you know how i can get to the display settings without this button or alternatively add this button?
Hi there Lambda,
You can go to Setting tab in the top menu, from there you can have the Post Processing settings.
Ameen Sir, It will be great if you could enlighten us with few solved examples of ALE and multi material ALE based problems. I am working on TNT detonation based problem. The problem can be stated as follows: Effect of TNT explosion is to be determined on dummy, air and soil. TNT is burried in soil . Dummy is laying over sand. It will be great if you can help. Best regards.
It seems that your request is very specific. I can make basic tutorials here. Maybe a general case for ALE.
Thank you very much, Sir. I will be waiting for your new tutorial regarding the case of ALE
hello i followed your sph and my blade is not blade but plate, al2024t3.
My problem is that my sph bird is not broken. It remains sphere and my plate is broken.
What is the problem..?
Most probably the material properties.
@@AmeenTopa I changed sph density more smaller, and now termination time is stopped.. analysis is still working but termination time is still 1.1264e-1 .
And when i see d3plot, it ends before contact to the plate.
@@shout_gopchang again, check units of the materials. In this tutorial, I am using kg, mm, ms, GPa units.
But does this simulation include aerodynamic loads on the propeller as well?
No. Aerodynamic loads are negligible when compared to impact from bird.
thanks for your initiative, can you upload a video for bullet motion inside a tube
Hi Yousaf, from my understanding to your statement, it seems that your request is very basic. I believe if you follow all my tutorials, you will be able to do it. :D
@@AmeenTopa thanks for your reply but I am facing problem for getting Blast wave as shown in the link storage.ansys.com/video/animations/pressure-in-barrel-and-silencer.mp4
Here they have coupled Euler and Lagrangian solver, but I am not able to getting the shock pattern.
Hey
iam in beginning phase of ls dyna do you help me to know how to add composite materails property into ls dyna softarwe,or else please send me a video which incloude a fathoming of composite material when it is utilized to apply stack. stack affect
Hey, LS Dyna is a very capable software and can do simulation of lots of things. Since you are still in beginner, I advise you first to grasp the basics of this software, how to simulate with normal material like metals, polymers...then you can advance to composite materials.
You cannot rush things, but you need to learn the basics first.
ya sir however my project of M.tech depends on composite materials, i,e contributing of composite materials for ballastic effect and examination of that materials utilizing ls dyna the disappointment rates et cetera that is the reason iam making little rush.
Hi ! I'm learning the software LS DYNA, and I don't understand something : can you explain the difference between doing an object (here the bird) with nodes and with elements with mesh ? I'm watching all your tutorials (thank you for that by the way) and previously you didn't use nodes to create objects. The question is why ? Thank you for your answer.
Hi. When the object (we call it part in LS DYNA) is expected to severely deform in the simulation, it is better not to model it with meshed elements. The distortion of the elements will be severe and hence errors may occur while solving the problem.
Nice Video.
I am working on similar project and have few doubts, can you help??
Thank you. Tell me more about your project please...
***** can you please share your email ID. I can send the details on the mail.
hi, can you make a tutorial on aircraft wing vibration analysis?
Hi there, you can check my tutorial on modal analysis!
ua-cam.com/video/VG8M95_5WYo/v-deo.html
Could you show turning simulation with material removal
Hi, if you follow all my tutorials, you will already be able to do the turning simulation. In this video, I showed how to impose rotational move. The same way, you can do the translational movement of the specimen.
The only extra thing you need to know is that you need to make the specimen with SPH particles.
Thanks for the video
my pleasure!
in this question,why u dont use LOAD?
We apply load usually when we want to find the stress due to some external force. To apply movement or rotation, we used PRESCRIBED MOTION or INITIAL VELOCITY.
after using(RUN) ls manger solver or ansys mechanical APDL launcher Solver,i am not be able to do binary 3D Plot,it is not showing when i open that file in ls dyna.why is it so?while same process i followed which u gave in this video.
I don't understand what you mean. If you follow my instructions, the solver will produce d3plot files. These files, you open then is ls prepost. Check my first tutorial for more details.
Thank you for your video
You are welcome. :)
Link to download LS-DYNA:
getintopc.com/softwares/simulators/ls-dyna-free-download/