LS-DYNA TUTORIAL 16: Car Collision - Hatchback vs Pickup Truck

After lots of requests, finally this video is out!
Unfortunately I don't have the time to make all of your requests, sorry for that. I am not a full time KZbinr (maybe will be, in the future :D )
This video is useful for you if you are doing your final year project or postgraduate research in crashworthiness. If you are someone from the industry, then I don't think there is much for you to learn from this video. But I'd appreciate it if you watch the video, and share your experience.
In this tutorial, I walk you through one of the car models available online. I also shared how to 'debug' some termination errors. The pickup truck is positioned in the opposite direction and then imported to the hatchback car model file. Contact definition is briefly discussed.
At the end of this video, I illustrated how to present the results nicely, change colors of the vehicle parts and how set the background as a picture. Lastly, I demonstrate how to make movie file from the d3plot results.
Here is the title of the paper that I've mentioned. If you are doing related research and found this video useful, don't forget the cite this paper! :D :D
Soltani, M., Topa, A., Karim, M. R., & Sulong, N. R. (2017). Crashworthiness of G4 (2W) guardrail system: a finite element parametric study. International Journal of Crashworthiness, 22(2), 169-189..
www.tandfonlin...
Links for car models:
www.ccsa.gmu.e...
www.nhtsa.gov/...
thyme.ornl.gov...
thyme.ornl.gov...
web.archive.org...
#lsdyna #tutorial #simulation #carcrash #accident #pickuptruck #collision #traffic #fem #fea #cae #crashworthiness #safety

[@AmeenTopa]

The following are some insightful input by Syazwan Samad (kzbin.info/www/bejne/q5mudJiihLStlZY) Just a general suggestions 1) It is better to use *include_transform with *define_transform to rotate one of the vehicle. Using this method, you don't have to redefine the initial velocity (generation) for each vehicle as the transform card will take care of it. Additional the offset id function is very useful as well, especially for a model that have similar ID range. One of the model (as includes) can be offset to prevent clash. 2) use the *parameter to define velocity *parameter_expression to relate the velocity to rotational velocity (of tyre), eg. w=v/r 3) contact between two different vehicle (or impactor) can be 'automate' by using *set_part_generate which you can define the range of part ID of two separate vehicle. Alternatively, in industries, we use boxes to define segment of the slave part in an include (when the include is plugged in into the model, the contact is 'automatically' defined). This is useful when you have a lot of barrier types with different IDs, especially the set part for the barrier need to be specifics. This will reduce the dependencies to lsprepost (or primer) a lot, and more towards text editor like notepad++. With this methods, there will be a lot of opportunities to do scripting for process efficiencies. We have done this, and to convert one loadcase to another (frontal impact to side impact for example) will take less than 1 minutes. with scripting, it is possible to generate multiple full vehicle crash model within 10s.

[@slava9019]

Ameen Topa sorry, i have a question .I did everything like in the video, but the animation does not work , for example, even with the example of a small car.why? in animate window last =1 and state =1;

[@AmeenTopa]

Is it normal termination or error termination? If error termination, check the messag file

[@slava9019]

@@AmeenTopa normal

[@slava9019]

@@AmeenTopa I really don't know but it worked, with 100 attempt . thanks very much-большое спасибо!

[@AmeenTopa]

@@slava9019 can you see the impact (deformation in both cars)? If yes, then you need to reduce the dt interval in datbase d3plot. If no, then you need to check both car models and make sure that the unit system is consistent.

[@prasadbartakke5037]

Thank you Ameen. Making this wonderful video. This video is really helpful for me to setup the crash simulation.....

[@AmeenTopa]

No problem! I am glad you found it helpful! Please share it so that more people can benefit! :D

[@keoagilekerileng663]

Indeed this is wonderful work, am about to setup a crash simulation, Impacting Steel column. Thank you very much

[@AmeenTopa]

You are welcome.

[@amindoxiti1201]

This the first youtube page which I check, thank you Ameen.

[@AmeenTopa]

Thanks! If you like my videos, pls subscribe to my channel and share my videos so more people can benefit! :D

[@sriharikurukuri5458]

wonderful video - will really be useful for learners. Thanks for sharing...

[@AmeenTopa]

Glad it was helpful! Please share it with your colleagues so more and more people can benefit from it! :D

[@Phenx]

Awesome tutorial, I didn't know this software. Thanks

[@AmeenTopa]

thanks. This is LS-DYNA, widely used in automotive safety applications.

[@dakshitha92]

Really appreciate you sharing this ❤️

[@AmeenTopa]

You are welcome! and thank you for sharing!

[@arieh00]

I'm studying crash collision in several diferent angles. My PC take about 7 hours to run this one. Could you please inform how can I reduce that time for me be able to study at diferent angles and sites of impact in each vehicle? I was searching for some free software to study crashworthiness and fortunately I found this. Thank you very much for this video!

[@AmeenTopa]

Hello, sorry for the late reply. I didn't see your notice. You can control the value in DT2MS to reduce the run time. However, 7 hour of running time is pretty standard on non-high performance PCs.

[@arieh00]

@@AmeenTopa I understand, Thanks for your reply.

[@nikolaosrapkos6749]

Best crash video !

[@AmeenTopa]

Thanks! Please support me and subscribe to my channel.

[@trickyabb]

thank you for taking time to teach us.

[@AmeenTopa]

My pleasure! Please share the video so more people can benefit!

[@nauday3085]

Awesome tutorial sir, thank you so much. Could you kindly give the link to the video about using CNRB as you mentioned in 2:28? I can't find the link in the description box

[@AmeenTopa]

Here you go kzbin.info/www/bejne/jKG1oWSnbN2chck

[@mohammednabilalbadani8498]

Thank you so much for this tutorial, Could you make a design of vehicle collision with bridge pier please?

[@AmeenTopa]

Dear Mohammed, I think I won't do that. If you follow and learn from all other tutorials on my channel, you will be able to do it. If there is possibly for research collaboration, then I can dedicate sometime for you.

[@mohammednabilalbadani8498]

@@AmeenTopa thank you for replying\

[@lesyphuc6853]

Hi Dr. Ameen, i’m come from VietNam. I'm studying for my master's degree and my thesis is also about collisions. It was very helpful to know your channel and watch these videos. Can you teach me the method how to simplify the vehicle model from C.G to rear and compensate the mass of the reduce component via nodal mass please Waiting for your reply, many thank you

[@AmeenTopa]

Hello there, I am glad that you found my channel useful. You can contact my team at [e-mail] to request for personal consultation services. Please provide them with all the details.

[@elenacommisso1885]

Hi Amen, congratulations for the channel. Very interesting. You could recommend a site where you can find 3-wave road barrier models. Thank you

[@AmeenTopa]

You can search in the links I gave in the video description.

[@yashchordiya5963]

Dear Ameen, thank you so much for making such elaborate videos, they are really helpful. I actually needed some suggestions from your side for a problem that I am facing and would be really grateful if you could help me out. I am trying to simulate a impact test between F800 (imported online) and a RC wall. I have assigned an automatic surface to surface contact between two parts. When I run the analysis it is getting exit automatically i.e., neither Normal termination nor error in termination. I am not able to figure out the problem, if you want I can share the .k file of the model with you. Hoping for a positive response from your end. Thank you.

[@AmeenTopa]

Dear Yash, Try to check the consistency of the units. Yes sure, you can share with me the file and I will have a look in my free time.

[@yashchordiya5963]

@@AmeenTopa Dear Ameen, thank you for such a quick and brisk reply. The consistency of units, it was suppose to be my next doubt. I am using MAT_159 for modelling the concrete wall but the problem with the material model is the set of units needs to be selected just as we select in Load_Blast_enhanced keyword. The unit system followed in the model of the vehicle is Sr. No. 10 from the units table i.e., ton, mm, s, N, MPa and unfortunately this option is not available in MAT_159 keyword. So, what can be done? May you please share your email ID and I can send the .k file! Thank you.

[@AmeenTopa]

If that's the case, then UNITS = 2, MPa, mm sec, Mg (Mega gram = tonne) Put your email here and I will contact you later. I am not near my PC now, I am replying using my phone.

[@yashchordiya5963]

@@AmeenTopa [e-mail]

[@AmeenTopa]

Done. Check your email.

[@lagtabhamza1676]

Hi Ameen thank you so much for this.. can we simulate the biomechanical modelisation using LS-DYNA ?

[@AmeenTopa]

We have human body models in LS-DYNA. So, we can do biomechanical simulations with the software.

[@kannansaravanan47]

Super explanation bro

[@AmeenTopa]

Thank you. Please share my videos for more can benefit 🙂

[@AntonioGarofano-x7k]

Hi, I am a master's degree student and I follow your videos to learn how to use Ls-Dyna. They have been very useful to me, thanks for sharing with us. I am doing impact analysis of aircraft structures in Ls-Dyna. In my model I have to join together parallel composite parts modelled with shell elements. What is the best approach to create a contact? I have used the tied_surface_to_surface_constrained_offset. Is this correct?

[@AmeenTopa]

You may use *CONTACT TIED SURFACE TO SURFACE OFFSET for perfect bonding. If you want to consider the separation between the parts, then use *CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_TIEBREAK with OPTION that considers offset for shell elements (such as OPTION = 8, 10 and 11). For more about the delamination, you may check the blog post below: lsdynauniverse.blogspot.com/2021/03/delamination-and-tiebreak-contact.html

[@AntonioGarofano-x7k]

@@AmeenTopa Thank you very much for your detailed reply. Your help was very useful for me to continue my analysis. I have modelled the contacts as you suggested. Are there any specific controls that need to be activated for the contacts or for the analysis?

[@AmeenTopa]

@@AntonioGarofano-x7k based on the model description given in your comments, there are no further recommendations from my side.

[@AntonioGarofano-x7k]

@@AmeenTopa Thank you so much for your reply and suggestions. Your suggestions and tips through the videos on this page allowed me to model a fuselage structure with skin, stringers and frames. I modelled all components as shell as part_composite with ELFORM 2, while the composite material through the material card 54. I bonded components through the contact_tied_surface_to_surface_offset approach as for your previous suggestion and applied an initial velocity to nodes of the structure, in order to simulate a drop test on a rigid surface. When the analysis starts, i get several unespected elements failure before the structure hits the ground and i noted a notable deformation of the components in the upper part of the structure. This is unespected at the beginning of the phenomenon as the structure is falling without any collision. Have you any suggestions to solve this issue? Are there any mandatory controls cards on contact, element, material, etc that i have to set?

[@AmeenTopa]

@@AntonioGarofano-x7k I believe there is an error or a typo in the material properties of the composite layers. Double check that. For testing, you can replace MAT054 with MAT001 and see if you still get this problem. If the elements are not prematurely being deleted, then we can confirm that there is something wrong with the input of MAT054.

[@MechanicalNib]

Loved it

[@AmeenTopa]

thanks! Please share the video so more people can benefit!

[@masoud6618]

Thank you Ameen. I watched this video to see how to find the Center of gravity of a car. there was not such info. Can you tell me how?

[@AmeenTopa]

You can use the Measure tool which provides lots of options.

[@anhphamcao2447]

thank you so much!👍

[@medriahi4933]

Hi sir , is there a way in LS DYNA to show the scratches that have been made by the accident ? or in any other software that u know ? thank you

[@0952382099able]

Hi Ameen, the one drive link for hatchback has expired, do you mind to reupload it again? I'm learning LS-DYNA from your tutorials, it has been immensely helpful. Thank you very much for the work you put in

[@AmeenTopa]

Dear Dave, please check these links: utpmy-my.sharepoint.com/:u:/g/personal/ameen_topa_utp_edu_my/Ea2I5lin-rNDg5eg3dlpCEYBdx--eGXt9tHBuZuJpUOYsw utpmy-my.sharepoint.com/:u:/g/personal/ameen_topa_utp_edu_my/Ea2I5lin-rNDg5eg3dlpCEYBdx--eGXt9tHBuZuJpUOYsw?e=dGZKwE

[@0952382099able]

@@AmeenTopa Thank you. You're the best!

[@maxengine6277]

where im need to download a ls-dyna? combine.k isn't work

[@sanskarsogani]

Hello sir, Thanks for this amazing video. I am trying to collide two cars, rear end collision with a cylinder fitted inside the front vehicle to check the impact on the cylinder. According to you how should I proceed to achieve this the best possible way without errors?

[@AmeenTopa]

That's a very general questions. Can you be more specific to what errors you are facing?

[@agustinremache6844]

good evening sir excellent video, excuse me a question to get the acceleration pulse curve of the vehicle what recommendation could you give me.

[@ritd2673]

Can you make a complete playlist of videos from basic for crash worthiness

[@AmeenTopa]

you can find them in LS-DYNA EXAMPLES list. :D Crashworthiness and other stuff too

[@roublard17]

Pickup’s rails yield stress is 385 mpa , but in simulation it can go up to 700 mpa , whats the logical explanation for it ?

[@AmeenTopa]

First: Yield stress is not the same as the ultimate stress. This is the basics, you should know these things. Second: It could be that the failure strain was not defined for this part. Check the material properties of the rails.

[@zurameen]

Link to download LS-DYNA: getintopc.com/softwares/simulators/ls-dyna-free-download/

[@metmey5828]

I want to confirm from you about impacting in incline angle that you have raised in this tutorial. Your rotate 30 degree, Vx=30, Vy= 40 so the car will move at velocity 50 and the angle is 36.8. This value 36.8 is OMEGA?

[@AmeenTopa]

No. OMEGA is the angular velocity. It is not the angle of impact. This OMEGA is used for the rotation of the wheels.

[@metmey5828]

@@AmeenTopa Thanks you, I get it

[@vishnubalasubramanian4514]

Is it possible to perform this analysis in student version . If means can you share the car model file which can be used in student version

[@AmeenTopa]

Yes, it is possible but only if the total number of nodes is less than 127k.

[@yashchordiya5963]

Dear Ameen, I have a question, In the rigidwall keyword we have a feature of exclude node set. This I have observed in many vehicle models? May you please tell what are these node sets, why are they excluded?

[@AmeenTopa]

In many files, I found they have four rigid walls. Each tire has one rigid wall. This could be because they want to find the reaction force at each tire. Or that, they created a tire model with a rigid wall, then they imported the file four times into the main model to get four tires. Why some nodes are excluded? The best answer I can say is to save the computational time. For example, the roof the car will not be in contact with the ground (unless you are simulating a rollover event), so we can safely exclude those nodes from the rigid wall. What are those nodes? I am not sure as I don't know which files you are referring to. You can see what value they put in NSIDEX, that's the ID of the node set. Then you go to Create Entity, Set Data, SET_NODE, and Show. Then find that node set ID. _________________________________________ For those who don't know, in RIGIDWALL PLANAR we can see: NSID:=Node set ID containing slave nodes, see *SET_NODE_OPTION. EQ.0: all nodes are slave to rigid wall. NSIDEX:=Node set ID containing nodes that exempted as slave nodes, see *SET_NODE_OPTION. BOXID:=All nodes in box are included as slave nodes to rigid wall, see *DEFINE_BOX. If options NSID or NSIDEX are active then only the subset of nodes activated by these options are checked to see if they are within the box.

[@vishnubalasubramanian4514]

Or how can I download the commercial version of the LS DYNA Software

[@AmeenTopa]

You may contact the ANSYS partner company/distributor in your country/region.

[@binumoljose8878]

Can you please do a video of vehicular collision on reinforced concrete bridge pier

[@AmeenTopa]

You can check my videos on concrete modelling: kzbin.info/www/bejne/i36UkJ-Zrdmhg68 kzbin.info/www/bejne/gavGZol8mtl1mqc kzbin.info/www/bejne/i17YhKSOaLynptE

[@xianggao6159]

Thanks for this amazing video. I have a question for this domain.If I want to transforlate a item from elastic to rigid and eventually become elastic,how should i do.Now ,I want to use keyword deformation ,but I can not make it.Can you help me?Thanks

[@AmeenTopa]

You can use the keyword DEFORMABLE TO RIGID. Check my tutorial Reinforced Concrete and Wrecking Ball. I used this keyword there.

[@MSVRises]

What material to use for car bumper crash with a tree. Material for bumper beam and tree ? I'm experimenting with Steel, Aluminum alloy ( AA6063-T6) , GMT

[@AmeenTopa]

For the bumper, you can use MAT024. For this tree, you can use MAT ELASTIC ORTHOTROPIC.

[@hapitelamien]

Thank you so much for sharing your knowledge about LS Dyna. Do you have, by any chance, done a simulation using soft elements, like using MAT 63 CRUSHABLE FOAM? For example for simple compression on cube soft solid. I've been looking for tutorials at KZbin or reading on journals but it's still not solved. Thanks in advance.

[@AmeenTopa]

Hi Hafidz, check out here my tutorial where I used this material model for Polystrene Foam: kzbin.info/www/bejne/aoezgol5oJp5aaM For more details, you can check my research paper here: www.hindawi.com/journals/mse/...

[@hapitelamien]

@@AmeenTopa thank so much!

[@hapitelamien]

@@AmeenTopa turns out I've been reading your paper "Modeling large deformation and failure of expanded polystyrene crushable foam using LS-DYNA" and I've been trying to validating my work with your numerical simulation on that paper and I have some questions regarding the simulation. Is it possible if I contact you via e-mail? My email is [e-mail] Thank you

[@AmeenTopa]

Done email. Please check your inbox.

[@sanyamsharma2980]

Very nice. 🙏😊

[@AmeenTopa]

Thanks a lot 😊 Please share with your circles so more people can benefit!

[@swapnilmane5759]

Thank you for the elaborated video, but both the car and pickup truck models disappear after the initial impact. can you please suggest a solution to this.

[@AmeenTopa]

There are many reasons that might cause this. I cannot give any useful answer due to the lack of information.

[@swapnilmane5759]

@@AmeenTopa Thank you for the reply. Would it help by changing the contact types or is there any problem in the material model?

[@AmeenTopa]

@@swapnilmane5759 The car models downloaded online are usually validated. It could be that the two models are not in the same unit system.

[@crayonelin]

wonderful videos and appreciate what you did for us. and i have a question, while i run the small car k file you share(the one you also show in your video), i have extra 4 errors, dyna said Cp must greater than Cv, i can't figure out is the units wrong on my pc? or something else problem, could u please reshare it? thank u so much

[@AmeenTopa]

This happens because the models were developed using older LS-Prepost. In older versions, the letter D is used to express the exponential (E). So, for an example, instead of 1.0E-5 it is 1.0D-5 in the older files. To solve this, you need to have an older version of LS-DYNA or you can use a text editor to correct all the exponent terms.

[@crayonelin]

@@AmeenTopa so thx for your reply, learn a lot from you.👍🏻

[@mohammedalamir753]

Dear Ameen, could you please explain how to do a car collision with bike to see the effective or analysis for the helmet. thank you

[@AmeenTopa]

Dear Mohammed, you need to have a model of a bike.

[@mohammedalamir753]

@@AmeenTopa thank you for your reply, and I am working on two journal papers regarding to this subject in USA. I will be appreciate it if you can help me with that’s. Also, I would like to add you with us as a co-author. Thank you

[@mohammedalamir753]

@@AmeenTopa thank you Ameen, my email is [e-mail]

[@musicawesome95]

Really appreciate it if you could teach me how to assign the material on ls dyna , maybe steel and aluminium for bumper beam :)

[@AmeenTopa]

This is very basic. Start from tutorial 1 and I am sure you will learn more than enough.

[@pradeepchirumamilla8125]

Thank u so much sir

[@AmeenTopa]

You are welcome. Please share this with others so more and more can benefit from it.

[@HieuTran-uu4lg]

Hello! Your videos are really useful. But I get the error ERROR 20978 (STR+978) Cp must be greater than Cv while running file SmolCar.k. Can you show me how to proceed? Thank you!

[@AmeenTopa]

You are welcome. You accidentally edited the values of these two parameters when you save the file with the new LS-PREPOST. Open the original file with any text editor and go to *AIRBAG to find the correct values of these two parameters.

[@HieuTran-uu4lg]

@@AmeenTopa but i do same as you not edited anything

[@AmeenTopa]

What's the value of Cp and Cv in your model and what's the unit system you are using?

[@HieuTran-uu4lg]

@@AmeenTopa In Smolcar.k Cv: 7.1700001 and Cp: 1.0039999 and I'm using LS DYNA Suite R13 for Student

[@danielhambissa5357]

thank you sir you are doing great....I am also doing my postgraduate thesis on crashworthiness and I hope this video will help me a lot ...is there is any textbook you can suggest to me to read on this?

[@AmeenTopa]

You can Google: Crashworthiness with LSDYNA. Pdf is available online.

[@danielhambissa5357]

@@AmeenTopa okey dear i will try that ....can i have your email please?

[@AmeenTopa]

Put your email here and I will follow up in my free time.

[@danielhambissa5357]

@@AmeenTopadear ameen Topa here is my gmail account..👉[e-mail] And thank you for your support

[@danielhambissa5357]

@@AmeenTopadear ameen Topa here is my gmail account..👉[e-mail] And thank you for your support

[@mohamedmoustafa7240]

hello DR Ameen, thanks for your video i want to use your pickup car model for a crash test to study the damage criteria on RC barriers so i want more details about the car like the weight and dimensions. also i want to ask if you define the gravity acceleration for the cars or not it is not important to define? thank you

[@AmeenTopa]

Dear Moustafa, You can find the mass and dimensions from Measure Tool. With this tool, you can measure the distance between any two nodes. Also, you can measure the mass by PART which will give you the mass of the part that you select. Gravitational acceleration 9.81 m/s are important if your simulation end time is long enough for the gravity to give an effect. If the time is short like 50 ms, then defining the gravity won't give much difference.

[@mohamedmoustafa7240]

@@AmeenTopa thank you so much

[@AmeenTopa]

@@mohamedmoustafa7240 No problem, please share my videos so it can benefit more and more people! :)

[@Alexandr8113]

Thx for the tutorial, it was very helpful. I have a question. I noticed that some vehicles, such as 2007 Chevrolet Silverado in Initial_Velocity_Generation Tab, have Vel_1 parameter and vehicle's speed can't be changed. What should I do to change it?

[@AmeenTopa]

You should find all the variables in *PARAMETER keyword. You can change frm there.

[@Alexandr8113]

@@AmeenTopa Thx, it's working.

[@roublard17]

@@Alexandr8113 bro, were can u change vehicule speed ?

[@AmeenTopa]

Dear Dem, you can see the tutorial. I discussed the keyword used for the velocity generation.

[@roublard17]

@@AmeenTopa oww my bad ,i got it now, thanks a lot for your time

[@Nostalgia-futuro]

Hello , i have a question, does this model provide the impact hit based on speed and Weight of object along with position.

[@AmeenTopa]

Both. The velocity of the object is initialised using INITIAL VELOCITY and the gravity effects are considered as well.

[@binhnghiem4489]

how to separate the frame from the car model in LS DYNA

[@AmeenTopa]

Search for the following video in my channel: "How to Extract part from a detailed model? LS-Prepost Tutorial" It should be helpful.

[@binhnghiem4489]

@@AmeenTopa thank you so much

[@Greco1114]

Does the program accept polygon models or they need to be created within a CAD program as solid or surfaces and then imported into Dyna?

[@AmeenTopa]

If you can see the models are .igs or .step, then you can import them to LS-Prepost.

[@Greco1114]

@@AmeenTopa Thank you

[@tunglinh7682]

衝突シミュレーションを実行できるように、車のフレーム ファイルをリンクしてメッシュ化してもらえますか?

[@AmeenTopa]

Sorry< I don't understand the language.

[@deepakbadoni1692]

Hi can you tell which one of your video is for blast loading on RCC/PCC members/structures or share it with me

[@AmeenTopa]

You can search in my channel: TNT Blast on Composite Beam

[@yashchordiya5963]

Dear Ameen, I need to ask you for the original reference of the small car model (CME-vehicles). I am unable to find it if I google it! Thank you.

[@AmeenTopa]

Dear Yash, Have you checked the links given in the video description?

[@yashchordiya5963]

@@AmeenTopa Yes, Ameen. I have checked it. I have to cite the source of this vehicle's FE model, so I need to ask you about the original source!

[@AmeenTopa]

@@yashchordiya5963 hmm..I thought I gave all the references. Anyway, the CME Vehicles can be found from the link to my drive. You download the files and open the keyword with a text editor. You should then find some details about the file.

[@longvanthanh4330]

thank you so much for this video, but i have a problem with elements eroded due to Negative volume. I have tried to many ways so many time, it's still eroded. ;( Can you help me please!!

[@AmeenTopa]

You can try to check this out: www.dynasupport.com/howtos/material/negative-volume-in-soft-materials

[@sabhajeetyadav9726]

I want to simulate crash on the wall. Will it be same procedure for that ??

[@AmeenTopa]

@@sabhajeetyadav9726 Yes. some of car models available online are prepared for frontal crash test, meaning, you have to only run these models without editing anything.

[@sabhajeetyadav9726]

@@AmeenTopa thank you

[@sabhajeetyadav9726]

Would you please provide me link for that please

[@AmeenTopa]

@@sabhajeetyadav9726 check the links in the video description.

[@sabhajeetyadav9726]

@@AmeenTopa I'm running the simulation in Ls- run but ist showing ( "s=" is not present ) in ls run and it terminated

[@yashchordiya5963]

Dear Ameen, I have tried to run this simulation and I have found out that even after defining the database cards in ASCII option, the corresponding ASCII files are not generated for this simulation. Can you please tell us why this issue occurs?

[@AmeenTopa]

There might be few reasons: 1 - You are not putting small enough value of DT in ASCII options. DT should be smaller than the termination time. 2 - For some ASCII options like curvout, nodout, secout, not thing will be written unless if you have DEFINE CURVE FUCNTION, HISTORY NODE, HISTORY CROSS SECTION, respectively. 3 - There is nothing to be written. For example, sphout, rcfor, rwfor won't give any data unless you have SPH part, contact defined, and a rigid wall, respectively.

[@yashchordiya5963]

@@AmeenTopa The termination time is given as 0.1 s and the dt is given as 0.1e-2. Also, contact is defined but still rcforc is not generated also the other options are not generated. ---------------------------- As mentioned by you in point 2 that we need to define some entities to get the corresponding. On a similar note, if I have defined beam section (reinforcement bars), so to get output in the beam section, I need to define History_Beam_set, am I right?

[@AmeenTopa]

@@yashchordiya5963 Yes, you are correct about the beam elements. The files are not generated altogether or they are written but contains no data?

[@theterch0120]

Thanks a lot for this tutorial , was wondering , How can i change the quadratic mesh that are in the pick up and the little car? I wanna do the uniform mesh (all black) so i can have more detailed solutions ?

[@AmeenTopa]

You can use Element Tools, Element Edit, Split. This is the most direct way and it will split the mesh that you have. It cannot change the type of elements. For more detailed solutions, I recommend to download the models with more elements, they are available online.

[@theterch0120]

@@AmeenTopa Ok thank you sir,but i dont understand something,in the car parts ,faillure is set on 1×10°8,thats a bit exessive no? I suppose its in Mpa,for example the chassis has 380 yield stress and 1×10°8 faillure

[@AmeenTopa]

@@theterch0120 the very high value of FS means that the engineers who made this model didn't consider the failure for that particular part.

[@theterch0120]

@@AmeenTopa ok thank you,is there a way to find failure values for each part? I cant even even find what material is on each part on that site u talked about caus i suppose car parts materials would be composite

[@AmeenTopa]

@@theterch0120 commercial cars don't use composite materials. Only super cars have composite for their components. To find the failure strain for each part, you need to see the material assigned to them. If you don't understand this statement, you need to check my first tutorial for the basics.

[@binumoljose8878]

Good work.thanks Is there any possibility to download different kind of vehicle model in ls dyna..

[@AmeenTopa]

I have put links in the video descriptions. You can find some models there.

[@binumoljose8878]

@@AmeenTopa How to provide different weight into the vehicle model

[@AmeenTopa]

You can increase the density of the parts. Or increase the values of point mass elements.

[@binumoljose8878]

@@AmeenTopa thank you sir

[@binumoljose8878]

Sir ..hoe to open vehicle model in ansys workbench.is that any possibility to open K file

[@AccelifeLiam]

brother ameen，I am doing a helmet impact simulation, but the acceleration of head model always been higher than i expected, what should i do

[@AmeenTopa]

Check the dimensions and properties of the helmet.

[@AccelifeLiam]

thank u ameen, and from the animation i saw that some elements of one part has been deformed and penetrated to another part, i guess it was negative volume, but i've tried every way to avoid it.@@AmeenTopa

[@AmeenTopa]

@@AccelifeLiam maybe a problem in the contact. check this one out: www.d3view.com/best-practices-for-modeling-recoverable-low-density-foams-by-example/

[@AccelifeLiam]

thank u so much, please keep updating your tutorials@@AmeenTopa

[@AmeenTopa]

You are welcome. Don't forget to support me by following this channel. 😁

[@andrea2128]

Hi ameen, you are great , i am doing tesi on ballistic impct , can i send my simulution to you for some evaluetions?

[@AmeenTopa]

Hi Andrea, yes sure. Put your email here and I will follow up. In case you haven't watched it yet, here is a tutorial for ball impact on plate. kzbin.info/www/bejne/aZLChWp-nZZsnbM

[@andrea2128]

@@AmeenTopa the email is : [e-mail],send me on e mail your contact so i Will show you some Result, i have seen your simulation but i have trown to do a simulation with solid element.

[@AmeenTopa]

Done email. Please check your inbox.

[@kadironsel1913]

Hey Ameen, thanks for this great instructive video. I have a question for you. I did the same what you did until 25:15 .But when I tried to run the PickUp file, one warning occured. "DATABASE_BINARY_INTFOR keyword found but "s=" is not present in command line. Submit job anyway". when I clicked ok, cmd screen gave me this "Warning 70005 (OTH+5) input file does not exist:... please define input file names or change defaults :" then the file status "terminated" in Ls run screen :( I will be appreciated if you can help with this problem ?

[@AmeenTopa]

You should add the extra command s = intfor which will create binary files called intfor. However, this should not be cause of termination error. It must be something else. If you scroll up in the run screen, you will find the reason stated.

[@kadironsel1913]

​@@AmeenTopa Thanks for replying. I scrolled up cmd screen but there was no difference between working file and this. Then I coppied the PickUp file (with 2 cars) and paste it in to some other file on dekstop. Then run it from there. İt surprisingly worked hahahah. Thanks for the vid again. bb :)

[@AmeenTopa]

Depending on your system, the name of the k files and the directory where you put them should not have any spaces. For example, E:Simulation\Car Collision\Test 1.k will not work because there are spaces between in "Car Collision" and in "Test 1.k"

[@kadironsel1913]

Yeah I've read that "no space condition situation". Actually there are some space in the directory file which has name "ls dyna youtube ex.". It is analysing even it has some space in file's name. But I will put no space from now on. Ps: It is still analysing. I have a student license so I can not run ls dyna more than 4 Ncpu. Is there any way to make runnig process faster?

[@kadironsel1913]

Btw the simulation has ended now. Small car acted like a rigid (unbroken) car. Interesting 🤔

[@vishnubalasubramanian4514]

are you doing these crash analysis in student version of LS DYNA

[@AmeenTopa]

Nope. In all my videos, I used the licensed software.

[@vishnubalasubramanian4514]

Is there any other way to install licensed software

[@vishnubalasubramanian4514]

Please 🙏🏼 do more videos on car crash test Analysis tutorials for beginners like this in Hypermesh . I beg you please do this in Hypermesh Student Version.

[@vishnubalasubramanian4514]

Do Licensed version and Student version separately so that It can be easy for me to learn and do

[@vishnubalasubramanian4514]

Please 🙏🏼 🙏🏼 🙏🏼 🙏🏼 🙏🏼 🙏🏼 🙏🏼 do these car crash test Analysis tutorials for beginners in both Hypermesh and LS DYNA Student Version Software

[@ryanadlertan4656]

Hello. Where do I find LS-DYNA Program Manager if I'm using the student version?

[@AmeenTopa]

With the student version, you must use LS-RUN. The program manager is only available if you have the full version.

[@ryanadlertan4656]

@@AmeenTopa Thank you so much for the clarification.

[@pisach100]

Any chance of sharing car CAD files?

[@AmeenTopa]

CAD files are not available. If you are looking for the FE models, then you can check the description of the video.

[@binhnghiem4489]

I want to separate link in model. Only run the Frame crash simulation, Can you help me.

[@AmeenTopa]

There is a video on my channel on how to extract seat from full car model. You can search that in my channel.

[@binhnghiem4489]

@@AmeenTopa Can you make a step-by-step video on frame collision simulation. Because I still don't understand the software ls dyna. I really need it please

[@AmeenTopa]

@@binhnghiem4489 To understand the software, you need to watch from the first lesson: LS-DYNA TUTORIAL 1: Ball Impact on Ball. If you want my personal help, I am available for online consultation. You can contact me through the website below: sites.google.com/view/topacademyofficial/home

[@binhnghiem4489]

@@AmeenTopa Thank you so much

[@lanA-d5o3n]

May I ask how to put the airbag and dummy into the car

[@AmeenTopa]

You can check my pinned comment for more tips about crash analysis.

[@lanA-d5o3n]

@@AmeenTopa Okay, but I still don't quite understand

[@AmeenTopa]

@@lanA-d5o3n Sorry for not being clear enough. What I mean, you need to find a sample model of dummy and air bag. If you have that, then you can import it to your simulation either by the method demonstrated in this video or by following the tips in the pinned comment.

[@lanA-d5o3n]

@@AmeenTopa Can you elaborate on how to operate it

[@AmeenTopa]

If you have the air bag and dummy models, then you can import to the car. You follow the same method I used in this tutorial. It is hard to explain in more details in the comment section. If you need further help, you can contact my team.

[@gandalfwiz20007]

I expect the solver to take 3 days to complete this🤣

[@medriahi4933]

Hi sir , ive done ur tutorial , is there a way to display von mises , tresca on the simulation ?

[@AmeenTopa]

Check my tutorial: POST PROCESSING WITH LS-PREPOST

[@medriahi4933]

@@AmeenTopa thank you very much , and is there a way to connect the 4 wheels to the full body ? i feel like it ruins the results when u define the contact between the two cars

[@AmeenTopa]

I don't understand what do you mean by connect 4 wheels to the full body? The wheels are already connected (linked) through the CONSTRAINED keyword and the interactions are defined using CONTACT keywords.

[@MGS-95]

Hi Ameen, can you explain how can we edit the car file, I have downloaded the Camry car model from the link attached but how to edit it? and are we able to convert it into a 3d model? please help. Thanks

[@AmeenTopa]

Assalamu alaikum Mohammad, I don't understand what do you mean when you say convert it to 3D model? The model is already in 3D.

[@MGS-95]

@@AmeenTopa w alaykom al salam Ameen I mean a solid 3D model, because it is a mesh and the extention of the file is .key, so I am not able to open it in Fusion 360 for example. What I want is to edit the model by removing the B-pillar, how can I do that? if you can please assist. Thanks

[@AmeenTopa]

@@MGS-95 There is no direct and easy way to do it. The best way, is that you have the original 3D geometry model from which the FEM keyword file was created. But these files are not usually available for public. The second option is that you look into GrabCad website and see if anyone has created the 3D model that you want. The last resort is using the keyword file to regenerate the 3D model with LS-Prepost. You can use the Surface Fitting tool but you need to this on every single surface. Moreover, if the surface is very complicated, then this tool will not work very well.

[@MGS-95]

@@AmeenTopa Thank you so much Ameen. Hope you the best

[@roublard17]

Hi , i downloaded the student version , i dont have program manager , how can i run the simulation please?

[@AmeenTopa]

Please check the follow video: kzbin.info/www/bejne/bJbMYn6ueNioY9U

[@roublard17]

@@AmeenTopa Hi , it actually worked , but my pc is slow so it takes a lot of time , and i keep getting theese warning in the cmd ; *** Warning 41231 (SOL+1231) Curve ID 5 has at least 2 points that define a negative slope. This may be unstable. //////////////////////////////////////// And this too : node number 57001 deleted at time 1.3945E-02 node number 57009 deleted at time 1.3945E-02 shell element 57000 failed at time 1.3945E-02

[@AmeenTopa]

@@roublard17 you can ignore these warnings. It is perfectly fine.

[@roublard17]

@@AmeenTopa Okey thanks a lot man ! one last question , were can u see or change the speed of the cars?

[@roublard17]

@@AmeenTopa Im verry sorry if i have too much questions , but when i ran the simulation , the four wheels of the pickup dislocated and kept on going , + the pickup windows got ejected to , i dont quiet get it ?

[@TomJE3031]

Can you give yourself a collision simulation of cars ???

[@AmeenTopa]

Sorry, I do not understand what do you mean...

[@TomJE3031]

@@AmeenTopa Can you send me the LSDYNA model files you already made. Is not it

[@jiayueding4314]

Hi Ameen, could you please explain how to apply a contact card between the structure and fluid domain (FSI Problem) using ICFD solver? I find it is different with applying a control card in a normal case like in this video.

[@AmeenTopa]

For ICFD, you need to use ICFD BOUNDARY FSI. You need have an ICFD part which covers the structure. Check out this example. www.dynaexamples.com/icfd/intermediate-examples/Intermediate_fsi_flap

[@jiayueding4314]

​@@AmeenTopa Yes i did the same thing as you said. But LS-Dyna always collapse at a certain point. i think this is because the solid flow through a smaller cross section area during the process (The cross-sectional area of the fluid domain gradually decreases) which results in a contact. Is this possible to solve this kind of problem with ICFD since i did not find examples like this.

[@AmeenTopa]

@@jiayueding4314 It is hard to imagine what you are trying to do. What is the name of the process or the problem that you are simulating? In general, with ICFD, the domain should be big enough to contain the structure. If the structure (and thus the ICFD part that interact with it) goes out of the domain, then a termination error will occur. To explain this, you see the example of rocket or missile launching where it moves from left to right. If I would allow the rocket to move further, it will hit the boundary on the right and cause termination error. kzbin.info/www/bejne/m3yVY5qKe8xnirM

[@jiayueding4314]

@@AmeenTopa Thanks for the reply! I am trying to simulate a forming process of fiber bundles. The fiber bundles will flow through a nozzle. At the beginning of the process the fibel bundles flow fluently because the fluid domain is big enough. But as the nozzle geometry changes, the fluid domain becomes smaller. When the fluid domain is not big enough to hold the solid domain , the termination error occurs. I will check the examples you attached above!

[@AmeenTopa]

So basically it is a like a flow through a nozzle. If your fiber are solid, then I don't think ICFD is suitable. ICFD is for incompressible fluids and gases modelling.

[@jimmyloluolajide7777]

Pls brother how I do I contact you?

[@AmeenTopa]

You can contact me through my social media. I have put the links in my channel main page.

[@Watashinojapancareer]

How you guys can make CAD for this simulation?

[@AmeenTopa]

I don't understand your question. This simulation was done using LS-DYNA software.

[@Watashinojapancareer]

@@AmeenTopa oke sorry, I mean What the software for modelling Car?

[@Watashinojapancareer]

Are you make with yourself or download modelling?

[@AmeenTopa]

@@Watashinojapancareer The software is called LS-DYNA (as you can see from the video title). The car models are available online and I've given links in the video description (if you read the description).

[@briandagoatscalabrine2982]

Do you know a way I could convert the car models to obj?

[@AmeenTopa]

There might be other software that can do this (try exploring hypermesh). As far as I know, with LS-PREPOST, it is not possible.

[@briandagoatscalabrine2982]

@@AmeenTopa Is there a difference between Hyperworks and hyper mesh if so where can I download it

[@AmeenTopa]

@@briandagoatscalabrine2982 Hypermesh is one of the software under Hyperworks group. You can go to their official website and contact them to get to your local distributor.

[@briandagoatscalabrine2982]

@@AmeenTopa How can I do it with Hypermesh? I’ve downloaded it

[@AmeenTopa]

@@briandagoatscalabrine2982 Sorry I am not the best person to ask about HyperMesh. You can check other KZbin channels.

[@walaaebrahim3977]

Can you import a solidworks file model into ls dyna?

[@AmeenTopa]

No....however, in solid works, you can save your file as igs format which is compatible with LS Prepost.

[@walaaebrahim3977]

I have a collage project and i don't know if it possible to use ls dyna for simulation

[@walaaebrahim3977]

@@AmeenTopa thanks a lot 💙💙

[@AmeenTopa]

To know if it is possible or not, you can search in journals for related work. If it is possible, then someone else must have done something similar to your project.

[@sayedalirezamousavi3713]

سلام امين ويديو به زبان فارسى هم دارى؟

[@AmeenTopa]

WaAlaikumussalam. Sorry I don't understand Farsi or Urdu.

[@viveknair0708]

Sir how can I rotate the vehicle with the help of mouse it's not working in my laptop..

[@AmeenTopa]

You mean rotate the view or rotate the position of the car? Check out my first tutorial Ball Impact on Ball to see the basics control.

[@viveknair0708]

@@AmeenTopa rotate the view zoom in,zoom out with the help of mouse

[@viveknair0708]

@@AmeenTopa sir how can I do the pedestrian collisions with vehicle and how can I get the free dummy full standing man..

[@AmeenTopa]

Dummy models are available online too. You need to search for them.

[@AmeenTopa]

I explained how to control the view in the video I told you about.

[@maxengine6277]

and what file im need to insert?

[@AmeenTopa]

To download the software, check my tutorial: How to get and install LS-DYNA (Student Version) It seems you don't have the basics of the software. Please watch from tutorial 1, don't jump straight to tutorial 16.

[@maxengine6277]

thanks, but i found it already@@AmeenTopa

[@AmeenTopa]

@@maxengine6277 Great!

[@maxengine6277]

also, how to change speed of car? im didn't watch the tutorial@@AmeenTopa

[@AmeenTopa]

@@maxengine6277 watch the tutorial. It is explained there how to change the velocity.

[@pritishsadhale1560]

Thank you so much for this tutorial. Can you extend your help to me on a personal level? If yes, kindly reply with your email id

[@AmeenTopa]

Hi Pritish, put your email id here and I will follow up.

[@pritishsadhale1560]

@@AmeenTopa Kindly reply on: [e-mail] Thanks and regards!!

[@anshuljaswal4229]

@@AmeenTopa me too sir , [e-mail]