Thank you for passing by my channel. Unfortunately, I cannot make video requests. However, if you are interested in a paid consultation service, you may contact my team
Thank you so much. I have learned a lot from your tutorial. I want to define preloaded under gravitational force before impact simulation which is called dynamic relaxation. Can you make tutorial or guidance how to do it?
Thanks for the video it was very helpful. I tried to perform the same steps on my part but i guess due to bigger part i got an error saying Memory is short. How can I get rid of it.
Hello sir....Thank you very much for learning tutorials... However I could not understand why we need to devided applied load by number of nodes...In practica, whole suface, hence all nodes will be subjected to 4 KN load....But we definded 4/820 KN on each node.....this need to be done in all kind of simillar probelm ?
If we didn't divide by the no. of nodes, then we will be applied 4kN on each nodes of the surface. If the surface has 100 nodes, then the total load applied with be 400 kN!! If you don't want to divide, no problem. But the force of 4kN will be concentrated on one single point which is not the case in real life.
Very thankful to you sir. Sir, I'm solving an explicit model (blast effect on the structure) but initially, I will have to apply load/force on the structure (as per condition), and then have to analyze blast effect on the structure. After inserting load curves for selected nodes, the solver is showing error termination. How to overcome this type of issue?
Hello. Thank you for the tutorial. can you please explain the function of the all "implicit" you used? i understand others but i don't seems to know what use of implicit.
Implicit keywords are to activate and control the implicit time integration scheme. For further information about this, you can look online for a document called "Tips and Tricks for Successful Implicit Simulation" by Dynamore.
Hello Dear!! How to decide the time duration of confinement and deviatoric loading if one wish to do triaxial test on cylindrical concrete specimen. Besides this, can u also give me some advice as in plotting curve, axis magnitude are not visible. Thanks in advance...
The start time of boundary conditions can be controlled wirh SPC SET BIRTH. And end time can be controlled by DEATH in SPC SET. Regarding the graph, you can check my tutorial on post processing.
Thank you for the video. I am trying for similar parameters but getting an error 60022 (IMP+22) saying "LS-DYNA Implicit is not supported in single precision, Please switch to DOUBLE Precision (I8R8) version". Can you suggest the solution to this?
The problem is quite clear. You are using single precision solver for implicit analysis. Implicit analysis can run only on double precision, for example smp_d_R10.
You can follow the same steps used here. However, instead of making solid cylinder. You make a hollow one. Check my tutorial on the following link where I covered how to make shell cylinder. th-cam.com/video/KVUBsmqkRxk/w-d-xo.html
This value depends on the RAM, not the CPU specs. You can try the same value, if it didn't work, then reduce it. But this simulation is not that big, you can leave it as default, it would be just fine.
Thank you for the tutorial. It is very useful! I tried modeling the exact same and if I increase the load it looks as if not all the nodes at the end where the force is applied have the same displacement. It looks as if every other node has a large displacement. The other nodes only have small displacements. Do you know why this occurs and how to fix it?
First thing to check, your nodeset. Make sure all the nodes on the surface is defined in the set. If this still doesn't work, then you can make a rigid plate on the top, then apply the force or displacement on that plate.
Thank you for the tips Mr Topa. I have already checked the nodes, and it looks as though they all are defined. So I think I'll try your solution with the rigid plate.
dear sir，May I ask why I used your method to analyze the bearing capacity of reinforced concrete columns? Why did the result obtained be greater than the force I applied? Thank you for your answer
Thank you for your video. I want to run compressive test of concrete cube. i do not know how to put experimental data for materials. which materials we have to choose. would you mind to help me?
am dealing with a concrete filled steel tube subjected to blast load.. i need to find out the mid-height deflection of the tube. for the above said problem i have divided the full length of the tube into three parts so as to find the deflection in the middle part. but i have been unable to establish the contact between the respective parts... can u suggest me the appropriate keyword that is to be used for establishing the contact between the parts.. waiting for ur reply... thanking u
i have also tried with one part that is without dividing but was unable to find the mid-height deflection of the tube.can u suggest me the CONTACT keyword that is to be used for creating the contact between concrete and steel..
Dear Ameen, I always learn from your turtorial evertime. As I model a single column and a regid cylinder was placed at top to aviod exessive local damage ( I merged duplicate nodes between the column and cylinder already). I have applied axial load the same as you. I have a few questions related to my modeling. 1) Does it need to defind the contact between regid cylinder and column, and its friction (FS, FD)? 2) I have watched yours turtorial (Reinforced Concrete and Wrecking Ball), when you defined Load_body_Z, you putted scale factor SF=1 but when I checked model truck F800 they put SF=9806. What these stand for? Do I need to assign gravity load on my model? Thanks in advance🙏
Dear Met mey, If you merge the duplicate nodes, then no need for any contact. SF is the scaling factor, in my tutorial, I defined the curve for gravity as 9.81 so there is no need for any scaling. But in the truck model, the curve has a value of 1, that's why they put 9806 as the scaling factor. They are using tonne, kg, mm, s units that's why the gravity constant is 9806 not 9.806 in their model.
Hi, I found this video to be very informative and I quite like it however, I followed the video to a tee and keep getting an Error 20001 reading 1st control card with improper format in line 2. Is there there a quick generic fix that any knows of for this? Thanks
Hello sir, i was trying to do the post processing display settings as shown in the video but I wasn't able to find the tool. Is it due to me having a student version?
No. It might be that you are using a different version of LS-PREPOST. For more tutorials about postprocessing, you can check my video "Postprocessing with LS Prepost".
So can we load already meshed surface with nice flow to get more accurate results.... and can we do this stimulation in different ways with less number of steps?
Hello. First of all great job on the tutorials, but when I want to define LOAD_NODE_SET and want to accept it i get warning Data of repeat card widget changed, but not saved. Then I save it but still getting same warning. What could be a problem to cause this issue?
ahaha, in 1 hour I noticed that in my version of LS-Dyna there is a subwindow with buttons insert, delete and replace (but it was not in the video), and AmeenTopa talked about these buttons in the comment.
"Finally after 32 minutes the analysis is done"That is because of the 99 completely unnecessary intermediate steps...using an implicit solver like an explicit one :)Still a great tutorial though!
If I intend to utilize an overpressure time history as a blast load, would the procedure be the same? If so, how does the software differentiate between the defined curve for pressure versus time and the curve for load versus time, given that the units for force and pressure are distinct?
am dealing with reinforced concrete column under blast loading. not getting how to make contact between the concrete ,stirrups and main reinforcement. Please suggest keyword for contact between the three. thank you
Hi, just a basic question. In LS-Dyna, in the legend for stress, why is compressive stress positive and not negative? For my specific problem, I have both positive and negative values of stress. How do I know which is compressive stress and which is tensile?
Following the standard convention in mechanics of solid, positive is tensile stress and negative is compression. What do you mean by 'compressive stress'? There is only x, y, z stress, shear stress, and effective stress options in contour plots.
@@AmeenTopa I mean, when looking at the legend for effective stress, for example, the legend goes from negative values to positive values. There are both negative and positive values of effective stress in the model. What do positive and negative stress values mean?
@@AmeenTopa means that the force distribution is taken from the total force to be evenly distributed on the surface, right, sir? Or is the total force distributed in the nodes sir?
if it inputs the load at each node, is there a way if I directly input the load on the surface with the load evenly distributed? or is there a way to calculate how many nodes are input on the load curve as a divider of the load? 
@@nathasya2492 if you do not want to calculate the force per node, then you can use LOAD RIGID BODY. With this option, you can directly put the total force to be applied.
Hey Ameen, could these steps be used in simulating the compression of reinforced concrete concrete columns except for having different material properties and models? Thanks
@@AmeenTopa hello Ameen, i have created a concrete column model to run a buckling test but i get an error message saying negative eigenvalues, could you please advise on how i can solve this issue. Thank you
Could you please tell the unit you are using for time. According to the other units you are using, it should be ms. But in the termination time you chose 1. Does it mean that the simulation is only for one millisecond?
Check my tutorial on Torsion. Quasi static analysis is usually done with implicit. Using explicit will take decades. In my Torsion tutorial I used mass scaling which reduces the computation time.
Vinod, you can model with Beam Elements, or shell elements as in this video. Instead of making solid cylinder, you can make hollow cylinder. The rest of the things should not different.
No problem. Sometimes, you need to apply distributed load instead of point load. The method used in Tutorial 4 is for you if you want to apply distributed load.
hi sir, i am new to this software and trying to learn from your tutorial. however, when i try to run analysis, it says error 70004. my steps and files saved as in the video.
Hello Sir, i want to attach Cfrp wrapping material to concrete column, it is just like frabic. I am not able to do this?. Any solutions, as i am not able to get results.
In define_curve...when I changed value of SIDR to 1 then while plotting it is showing invalid curve id ......this is happen when I am doing dynamic relaxation method.....any solution?
I am just wondering about the NCPU=8. Was the computer that you used for the static analysis is an HPC? I was trying to model a large-scale model and it required time of 55hrs. any suggestions to speed up the simulation?
CPU time depends on many factors such as: file size, number of elements, and elements quality. If your keyword file size is 200 Mb or above, then it is normal that it would take that amount of time.
@@AmeenTopa Thank you very much for the reply. The file size is 23 Mb though. If I want to do a simulation for the half of the model (cut along a symmetric axis), how should I apply the boundary condition to the cutting plane? Also, do I need to input or consider any other keywords or factors in addition to the boundary condition? and after I simulate the half model, how should I scale up the values for the full model?
If that's the file size, and you are doing static analysis, then I assume you are using implicit solver. If my assumption is right, then you can use variable time step, and control the initial time step. For model reduction, you don't need go remove or reduce the load, you can simply apply boundary conditions at the symmetric plane with BOUNDARY SPC SET or use SPC SYMMETRY PLAN condition like in my video here. th-cam.com/video/Xidr0p6EplQ/w-d-xo.html
@@AmeenTopa Thank you very much. You are right, I am applying a static load through a spherical ball on a wall. Ye, I tried with implicit solver with variable time step (after watching one of your videos) but it is still taking longer time. I will try with the SPC SYMMETRY PLAN and check. Thank you very much for your much helpful videos and advice.
@@amzzano For implicit analysis, everything should be fixed and there is not 'loose' ends. If there is some gap between the ball and the wall, then this might cause your run time to go very large. The ball should be touching the wall at the beginning of the simulation. The wall (if you are using shell or solid part) should be fixed too at its boundaries.
Ameen Topa thank you for this....but do you have any pdf for dynamic relaxation method because its hard to understand this method....if you have any video or document ..that will be helpful for me
Thanks for all your tutorial videos Ameen. It so easy to follow. I'm currently trying go learn how to do a compressive testing of a concrete specimen and tried to follow this video. Could you please do a video on how to simulate the compressive testing on a concrete cylinder sample? It differs from this problem in a sense that force is applied until the concrete sample cracks, and the output required for the test is a stress-strain curve. (I could only find a tutorial on this using ABAQUS th-cam.com/video/PTRQib7C6po/w-d-xo.html) It would be greatly appreciated!
Dear sir, Thank you very much! I am very grateful for your tireless efforts on ls-dyna tutorial.
Dear Zhu, you are most welcome. Thank you for your support!!! :)
its wonderful sir,
but how we define nominal stress and strain curve in ls dyna for crushable foam material or MAT-57 ?
thank you
Check my tutorial on Three Point Bending of Sandwich Structure
Thank you so much. Could you please make a video about solving this model in explicit solver?
Just delete the IMPLICIT keywords and the software will run this problem with the explicit solver.
thank you so much for this excellent tutorial. I still wonder. Can you make the same thing on the shell plate
You can check my tutorial here:
th-cam.com/video/3lqeqYbAzoo/w-d-xo.html
Thank you for the great video! Do you know any examples related to pressure?
To apply pressure, first define SEGMENT SET then use LOAD SEGMENT SET.
Thank you so much. Could you please make a video about the concrete composed of dem particles?
Thank you for passing by my channel.
Unfortunately, I cannot make video requests. However, if you are interested in a paid consultation service, you may contact my team
cae-works@outlook.com
thank you very much. I hope you upload more tutorials.
more tutorials will come eventually
Thank you so much. I have learned a lot from your tutorial. I want to define preloaded under gravitational force before impact simulation which is called dynamic relaxation. Can you make tutorial or guidance how to do it?
No need. There are already tutorials on TH-cam and examples online for dynamic relaxation. You can simple search for it.
excellent exercise to check the process and results!
Thanks Victor, please share my videos so more can benefit! :D
Your videos are just awsum!!!!
Please subscribe and tell your friends about my channel. The more subscribers the more I will be motivated to upload more videos hehee
Thanks for the video it was very helpful. I tried to perform the same steps on my part but i guess due to bigger part i got an error saying Memory is short. How can I get rid of it.
It seems that your computer does not have enough RAM memory. You may reduce the size of the mesh and have less elements.
Hello sir....Thank you very much for learning tutorials...
However I could not understand why we need to devided applied load by number of nodes...In practica, whole suface, hence all nodes will be subjected to 4 KN load....But we definded 4/820 KN on each node.....this need to be done in all kind of simillar probelm ?
If we didn't divide by the no. of nodes, then we will be applied 4kN on each nodes of the surface. If the surface has 100 nodes, then the total load applied with be 400 kN!!
If you don't want to divide, no problem. But the force of 4kN will be concentrated on one single point which is not the case in real life.
Very thankful to you sir. Sir, I'm solving an explicit model (blast effect on the structure) but initially, I will have to apply load/force on the structure (as per condition), and then have to analyze blast effect on the structure. After inserting load curves for selected nodes, the solver is showing error termination. How to overcome this type of issue?
Hi, I have made more than one video about blast simulation with LS DYNA. Please check them out.
Hello. Thank you for the tutorial. can you please explain the function of the all "implicit" you used? i understand others but i don't seems to know what use of implicit.
Implicit keywords are to activate and control the implicit time integration scheme. For further information about this, you can look online for a document called "Tips and Tricks for Successful Implicit Simulation" by Dynamore.
Hello Dear!! How to decide the time duration of confinement and deviatoric loading if one wish to do triaxial test on cylindrical concrete specimen. Besides this, can u also give me some advice as in plotting curve, axis magnitude are not visible.
Thanks in advance...
The start time of boundary conditions can be controlled wirh SPC SET BIRTH. And end time can be controlled by DEATH in SPC SET.
Regarding the graph, you can check my tutorial on post processing.
it,s very nice and good explanation how to do crash rectangle box simulation non liner material with explicit method can pls make videoo
Hi there, I already have that video. You can search in TH-cam: "ameen topa tube crush"
Thank you for the video. I am trying for similar parameters but getting an error 60022 (IMP+22) saying "LS-DYNA Implicit is not supported in single precision, Please switch to DOUBLE Precision (I8R8) version". Can you suggest the solution to this?
The problem is quite clear. You are using single precision solver for implicit analysis. Implicit analysis can run only on double precision, for example smp_d_R10.
can you upload a video on doing a thin tube structure subjected to axial load?
You can follow the same steps used here. However, instead of making solid cylinder. You make a hollow one. Check my tutorial on the following link where I covered how to make shell cylinder.
th-cam.com/video/KVUBsmqkRxk/w-d-xo.html
Thanks for great tutorial, and I have a question why you write 99999 before analysis? What should I write? I have i5 7300 hq 4 core 3.2 ghz
This value depends on the RAM, not the CPU specs.
You can try the same value, if it didn't work, then reduce it. But this simulation is not that big, you can leave it as default, it would be just fine.
Thank you for the tutorial. It is very useful! I tried modeling the exact same and if I increase the load it looks as if not all the nodes at the end where the force is applied have the same displacement. It looks as if every other node has a large displacement. The other nodes only have small displacements.
Do you know why this occurs and how to fix it?
First thing to check, your nodeset. Make sure all the nodes on the surface is defined in the set.
If this still doesn't work, then you can make a rigid plate on the top, then apply the force or displacement on that plate.
Thank you for the tips Mr Topa. I have already checked the nodes, and it looks as though they all are defined. So I think I'll try your solution with the rigid plate.
@@nikoline5299 here is how i did before with the rigid plates
th-cam.com/video/LJXrcC4pCu8/w-d-xo.html
dear sir，May I ask why I used your method to analyze the bearing capacity of reinforced concrete columns? Why did the result obtained be greater than the force I applied? Thank you for your answer
It could be that you are applying the force in a very fast rate, which causes inertial forces. Thus, the resulted force is higher.
Thank you for your answer, but I would like to know at what speed it is appropriate to apply force
@@houa-lk9bd the velocity should be same as the experimental work. That's the ideal way to do it.
@@AmeenTopa ok thank you sir
@@houa-lk9bd you are welcome
Thank you for your video. I want to run compressive test of concrete cube. i do not know how to put experimental data for materials. which materials we have to choose. would you mind to help me?
Hi there. Yes sure. You can use MAT024. Watch my tutorial on blast wall where I showed how to use experimental data as input for this material model.
am dealing with a concrete filled steel tube subjected to blast load..
i need to find out the mid-height deflection of the tube.
for the above said problem i have divided the full length of the tube into three parts so as to find the deflection in the middle part.
but i have been unable to establish the contact between the respective parts...
can u suggest me the appropriate keyword that is to be used for establishing the contact between the parts..
waiting for ur reply...
thanking u
Dear Sumit, you don't need to divide into three parts. Just make it one part but with nice and small mesh.
i have also tried with one part that is without dividing but was unable to find the mid-height deflection of the tube.can u suggest me the CONTACT keyword that is to be used for creating the contact between concrete and steel..
will u please let me know ur email id so that i can get in touch with u regarding this by sending the file.
Dear Ameen, I always learn from your turtorial evertime. As I model a single column and a regid cylinder was placed at top to aviod exessive local damage ( I merged duplicate nodes between the column and cylinder already). I have applied axial load the same as you. I have a few questions related to my modeling.
1) Does it need to defind the contact between regid cylinder and column, and its friction (FS, FD)?
2) I have watched yours turtorial (Reinforced Concrete and Wrecking Ball), when you defined Load_body_Z, you putted scale factor SF=1 but when I checked model truck F800 they put SF=9806. What these stand for? Do I need to assign gravity load on my model?
Thanks in advance🙏
Dear Met mey,
If you merge the duplicate nodes, then no need for any contact.
SF is the scaling factor, in my tutorial, I defined the curve for gravity as 9.81 so there is no need for any scaling.
But in the truck model, the curve has a value of 1, that's why they put 9806 as the scaling factor. They are using tonne, kg, mm, s units that's why the gravity constant is 9806 not 9.806 in their model.
By the way, if you learn from my videos, make sure to share my channel to your friends and colleagues.
@@AmeenTopa Yes I did share it, of course. Thanks you
Hey there. You cannot put your email here. TH-cam will automatically delete your comment. Please reach me over my social media (Facebook or LinkedIn)
Hi, Could you prepare anything related to modeling of RC frames??
Hi Devkota, you can check this one: th-cam.com/video/Kzc5VFetBdE/w-d-xo.html
how to construct reaction force to time graph on ls dyna?
You can check my tutorial: "POST PROCESSING with LS-PREPOST"
Hi,
I found this video to be very informative and I quite like it however, I followed the video to a tee and keep getting an Error 20001 reading 1st control card with improper format in line 2. Is there there a quick generic fix that any knows of for this? Thanks
You can open the file with a text editor and delete line 2.
Hello sir, i was trying to do the post processing display settings as shown in the video but I wasn't able to find the tool. Is it due to me having a student version?
No. It might be that you are using a different version of LS-PREPOST.
For more tutorials about postprocessing, you can check my video "Postprocessing with LS Prepost".
Hello Sir, How can we do wrapping of material to concrete using LS-Dyna
Hi, what do you mean by wrapping material to concrete?
So can we load already meshed surface with nice flow to get more accurate results.... and can we do this stimulation in different ways with less number of steps?
You can control the number of timesteps if you are using Implicit solver.
Hello sir,I just follow the step the same as you do,but the launch manager result shows " Termination Error",can it be solved?
Scroll up the message and the cause of the error will be mentioned.
Hello. First of all great job on the tutorials, but when I want to define LOAD_NODE_SET and want to accept it i get warning Data of repeat card widget changed, but not saved. Then I save it but still getting same warning. What could be a problem to cause this issue?
Every time you enter a set off data, make sure that you click first on insert or replace before you click on Accept.
I have the same problem, did you solve it somehow?
ahaha, in 1 hour I noticed that in my version of LS-Dyna there is a subwindow with buttons insert, delete and replace (but it was not in the video), and AmeenTopa talked about these buttons in the comment.
"Finally after 32 minutes the analysis is done"That is because of the 99 completely unnecessary intermediate steps...using an implicit solver like an explicit one :)Still a great tutorial though!
you should make a video for a simplified one then? please do
please follow my tube crush tutorial.
If I intend to utilize an overpressure time history as a blast load, would the procedure be the same? If so, how does the software differentiate between the defined curve for pressure versus time and the curve for load versus time, given that the units for force and pressure are distinct?
If you use *LOAD SEGMENT SET, then the input curve should be pressure vs time. If it is *LOAD NODE SET, then a force vs time curve should be used.
@@AmeenTopa ok ok. Should overpressure be divided by number of segments?
@@shriyaverma2565 overpressure is N/m2 so it is already per unit area. So there is no need....
@@AmeenTopa Thankyou so much.. I really appreciate your help.
@@shriyaverma2565 you are welcome.
am dealing with reinforced concrete column under blast loading. not getting how to make contact between the concrete ,stirrups and main reinforcement. Please suggest keyword for contact between the three. thank you
Dear San, please check out my tutorial here: th-cam.com/video/Kzc5VFetBdE/w-d-xo.html
Hi, just a basic question. In LS-Dyna, in the legend for stress, why is compressive stress positive and not negative? For my specific problem, I have both positive and negative values of stress. How do I know which is compressive stress and which is tensile?
Following the standard convention in mechanics of solid, positive is tensile stress and negative is compression.
What do you mean by 'compressive stress'? There is only x, y, z stress, shear stress, and effective stress options in contour plots.
@@AmeenTopa I mean, when looking at the legend for effective stress, for example, the legend goes from negative values to positive values. There are both negative and positive values of effective stress in the model. What do positive and negative stress values mean?
@@m.kazimali6918 positive means tensile state of stress whole negative means compressive
When loading the curve, is the load value entered the nodal load value or one load value for the surface on SET_NODES, sir?
In this model, I entered the total load. That's why I used scaling factor.
@@AmeenTopa means that the force distribution is taken from the total force to be evenly distributed on the surface, right, sir? Or is the total force distributed in the nodes sir?
if it inputs the load at each node, is there a way if I directly input the load on the surface with the load evenly distributed? or is there a way to calculate how many nodes are input on the load curve as a divider of the load?

@@nathasya2492 if you do not want to calculate the force per node, then you can use LOAD RIGID BODY. With this option, you can directly put the total force to be applied.
Hey Ameen, could these steps be used in simulating the compression of reinforced concrete concrete columns except for having different material properties and models? Thanks
Hi there, you can follow this tutorial:
th-cam.com/video/Kzc5VFetBdE/w-d-xo.html
@@AmeenTopa yes i used that for concrete modelling but i want to apply axial loads on the column, should i use this tutorial?
@@nj5587 Yes, you can follow the tutorial here and take the material properties from there. Just make sure that the units are consistent.
@@AmeenTopa ok thank you very much
@@AmeenTopa hello Ameen, i have created a concrete column model to run a buckling test but i get an error message saying negative eigenvalues, could you please advise on how i can solve this issue. Thank you
Could you please tell the unit you are using for time. According to the other units you are using, it should be ms. But in the termination time you chose 1. Does it mean that the simulation is only for one millisecond?
Here, as I am using static implicit solver, the value of time does not really matter.
@@AmeenTopa Thank you very much
Hey Ameen, do you have a tutorial for explicit quasi static analysis?
Check my tutorial on Torsion.
Quasi static analysis is usually done with implicit. Using explicit will take decades. In my Torsion tutorial I used mass scaling which reduces the computation time.
@@AmeenTopa do you reckon that buckling of a reinforced concrete column can be computed using an explicit solver and mass scaling?
@@nj5587 if you want to compare the buckling load with theoretical values, I suggest you go for implicit. Buckling load is a very sensitive analysis.
@@AmeenTopa alright, ive already managed it in implicit, i just wanted to add explicit results and compare all them
@@nj5587 There is only one way to be sure. You have run and find out!
Thank you
You're welcome. Please share my videos so more people can learn. :D
Dear sir, how can we model tabular column in Ls-Dyna?
Vinod, you can model with Beam Elements, or shell elements as in this video. Instead of making solid cylinder, you can make hollow cylinder. The rest of the things should not different.
Splitting the force into 820 parts is hard to understand. Can the pressure curve be defined directly in LS-DYNA？
Yes. You can directly define the pressure: th-cam.com/video/5Sgwna3IHCg/w-d-xo.html
@@AmeenTopa Thank you for your help！
No problem. Sometimes, you need to apply distributed load instead of point load. The method used in Tutorial 4 is for you if you want to apply distributed load.
how can i find the mid height deflection in a beam problem?
Follow the same steps. POST PROCESSING. HISTORY. NODAL. Then select an element in the middle of the beam.
hi sir, i am new to this software and trying to learn from your tutorial. however, when i try to run analysis, it says error 70004. my steps and files saved as in the video.
anything please you can email me at faizsyazwan23@gmail.com . have a nice day sir
I have replied to your email. Please check your inbox. Thanks!
Link to download LS-DYNA:
getintopc.com/softwares/simulators/ls-dyna-free-download/
Hello Sir, i want to attach Cfrp wrapping material to concrete column, it is just like frabic. I am not able to do this?.
Any solutions, as i am not able to get results.
You may use shell elements, then use tied nodes to surface contact.
@@AmeenTopa hello sir, i have used it but i am not able to get proper results.
@@vinodbankapur2717 gimme your email id. I will contact you there for further consultation.
@@AmeenTopa vinodsb@consultant.com
How about contact? You dont define any contact in this case?
No need for contact since we have only one part.
In define_curve...when I changed value of SIDR to 1 then while plotting it is showing invalid curve id ......this is happen when I am doing dynamic relaxation method.....any solution?
I am not sure what is the reason of the problem. I just tried in with my prepost. There is no problem in plotting the curve whether SIDR is 0 or 1.
Ameen Topa is it necessary to create two load curves while doing dr method
Yes, one load for the initialization and one load for the transient simulation
I am just wondering about the NCPU=8. Was the computer that you used for the static analysis is an HPC? I was trying to model a large-scale model and it required time of 55hrs. any suggestions to speed up the simulation?
CPU time depends on many factors such as: file size, number of elements, and elements quality. If your keyword file size is 200 Mb or above, then it is normal that it would take that amount of time.
@@AmeenTopa Thank you very much for the reply. The file size is 23 Mb though. If I want to do a simulation for the half of the model (cut along a symmetric axis), how should I apply the boundary condition to the cutting plane? Also, do I need to input or consider any other keywords or factors in addition to the boundary condition? and after I simulate the half model, how should I scale up the values for the full model?
If that's the file size, and you are doing static analysis, then I assume you are using implicit solver.
If my assumption is right, then you can use variable time step, and control the initial time step.
For model reduction, you don't need go remove or reduce the load, you can simply apply boundary conditions at the symmetric plane with BOUNDARY SPC SET or use SPC SYMMETRY PLAN condition like in my video here.
th-cam.com/video/Xidr0p6EplQ/w-d-xo.html
@@AmeenTopa Thank you very much. You are right, I am applying a static load through a spherical ball on a wall. Ye, I tried with implicit solver with variable time step (after watching one of your videos) but it is still taking longer time.
I will try with the SPC SYMMETRY PLAN and check. Thank you very much for your much helpful videos and advice.
@@amzzano For implicit analysis, everything should be fixed and there is not 'loose' ends. If there is some gap between the ball and the wall, then this might cause your run time to go very large.
The ball should be touching the wall at the beginning of the simulation. The wall (if you are using shell or solid part) should be fixed too at its boundaries.
Thank you so much
you are welcome!
hello sir.....I want to do dynamic relaxation of beam in LS dyna......but I dont know how to do...pls tell
Hai. Please refer to the following document:
ftp.lstc.com/anonymous/outgoing/jday/bolt_preload3.pdf
Ameen Topa thank you for this....but do you have any pdf for dynamic relaxation method because its hard to understand this method....if you have any video or document ..that will be helpful for me
can I do dynamic relaxation method on any other software other than ls Dyna...please reply
Sorry Rahul, I have no idea about other softwares
www.dynaexamples.com/show-cases/preload/preload/?searchterm=relaxation
BECAUSE THE BOOK !
Yes, you really need to have the book!
Error 70022 (OTH+22)
I am no wizard. You need to give more details.
Thanks for all your tutorial videos Ameen. It so easy to follow. I'm currently trying go learn how to do a compressive testing of a concrete specimen and tried to follow this video. Could you please do a video on how to simulate the compressive testing on a concrete cylinder sample? It differs from this problem in a sense that force is applied until the concrete sample cracks, and the output required for the test is a stress-strain curve. (I could only find a tutorial on this using ABAQUS th-cam.com/video/PTRQib7C6po/w-d-xo.html) It would be greatly appreciated!
p.s it would be very similar to your tutorial video 12.. Thank you so much in advance!
th-cam.com/video/RrsChFqZk7g/w-d-xo.html
You can check my tutorial: compression on cylinder