Great videos always!! I often use RBE2 + Beam idealization to idealize my models and also size the bolts by extracting gpforces of the beam elements (tension / compression). But this obviously cause stress concentrations on the RBE2 dependent nodes (bolt heads or flanges overly idealized) since it blocks all the dofs hence no bolt shear is considered. Thus I often ignore the stress concentrations and make notes of this. You could also hand-calculate the bearing stress of the plates based on the gpforces of the beam elements. On the other hand, RBE3 does not block any dofs on the independent nodes since it only transfer loads, meaning there is no bolt heads or flanges stiffness considered. Also this is why you would likely see less stress concentration effects when using RBE3. I can’t answer which method is correct or wrong, but every analyst should decide based on the level of interest. The best way is to run a nonlinear contact with a bolt idealized with solid elements but it is super time consuming.
Agreed, as no model of 1D bolt can be regarded as perfect, it's upto the analyst to decide based on the requirements. Right! Gpforce can be used to extract tension/compression. I have used gpforce to extract nodal force values at specific node locations in the model but didn't know it also works for Beam elements. Thanks for the info!
Great video👍 Helped a lot🙌 I have a question, why we always prefer to use RBE2 over RBE3 around hole, wherever we've to apply the constraints or forces, just like we saw in the case of static structural analysis(in previous videos) of knuckle, we have make use of RBE2 elements around hole/mounting and accordingly we have applied constraints & forces, we would have prefer RBE3 since it distribute forces around the connected nodes. Thank you and looking forward to your reply.
Hi Shashwat, Good question! The location of independent and dependent nodes is reversed on case of RBE3. This can cause errors in the analysis if the RBE3 element is not defined correctly. As a general practice to avoid complexities, RBE2 is used for load application and RBE3 is used for mass addition and bolted joints. I hope this answers your question :)
Very good video. But it is better if you can compare the results with e xperimental data or analytical calculation to find the best accuracy model. And could you please share the methods to model the bolt between 2 3D parts ?
Thank you. I have already posted tutorials about 1D as well as 3D bolt modelling. Please check the 'Optistruct Tutorials' playlist to find these videos.
Thank you Umesh. Basically, we have have any required property and material for a beam bolt. The method to create the bolt is exactly the same as I demonstrated. Feel free to experiment with different materials and cross-sections. As for rigids, they are non-deformable 1 dimensional entities. > 1 dimensional so no cross-section (property) > Non- deformable so no material I will work on a separate video to explain beam, and rod differences. Thanks for the suggestion!
Thanks for response, by the way you are pretty straight to topics where there is no introduction of self and no subscribe , no share kind of thing.. keep doing the videos...
Thank you for your tutorial videos on hypermesh. Just want to ask the 3rd method you told can it be used for multiple plates like 4 plates are their and a single bolt is passing through. Waiting for your answer.
Hi Miheer, Good question. Yes, this method can be used to create a bolted joint between more than 2 plates. However, certain modifications are required. If rigids are created only on the lower and upper plates, there will be no contact between bolt and the middle plate. To avoid this, a rigid must also be created on the middle plate. I hope this helps.
Thanks Amogh, I'm glad you liked the videos :) If you need any help, feel free to reach out via email. My contact details are provided in the 'About' section of this channel.
Hello bro, your connectors video helped a lot!!! But I have a doubt regarding bolt connectors. If we want to fasten more than 2 components together with a single bolt, do we have to apply RBE3 elements only on the top and bottom components and not on the middle components? Please explain.
Solid bolt cannot be modelled in Hypermesh directly. You have to import the bolt CAD and specify the pretension and contact settings to get the bolted joint properties as required!
Good question! In that case, you will observe very high deformations as RBE3 does not work like RBE2. As the locations of dependent and independent nodes are interchanged, the behaviour changes drastically. The plate on which force is applied will practically 'fly away' with infinite deformation and the RBE3 element will be seen to stretch accordingly. It's an interesting thing to watch, feel free to setup this case and observe the results.
@@Aeroswap hey man, very informative video. I tried this direct RBE3 like RBE2 and the part did 'fly away' with large deformation. my question is, I tried to connect two RBE3 with the CBEAM as you have shown above, but still one of my part flies away with large deformation ? Can you think of a reason why ? Please help.
Hi Suyog, Please check if the CBEAM is exactly attached to the center node of each RBE3 element. Also check if a material and property is assigned to the CBEAM. This should resolve the error.
@@Aeroswap Hi, thank you for the quick reply. Yes the CBEAM is attached exactly on the two RBE3 points. However I would like to check these two points with you : (1) I used property as PBEAM and not as PBEAML, because then i was getting this error : *** ERROR # 1479 *** in the input data: Incorrectly formatted numeric data in field 9 [there is a random "+" in field 9] can that be the reason ? (2) also in above example, the bolt axis is perpendicular to x axis, so that's good. but in my case, the bolt axis is not perpendicular to any of the three axis does the axis have to be perpendicular and if yes, then how do I define it in my example ? Thank you once again for your help, I tried looking for these questions, but I could not get much information on google for these.. :)
Hi Suyog, PBEAM and PBEAML have some inherent differences. In PBEAML, we can define the cross section using standard geometrical shapes (example : square, circle). We do not have to enter the area of cross section as it is directly calculated based on these geometrical shapes. On the other hand, PBEAM is used to define a much more complex cross section. If the cross section cannot be created by standard shapes, PBEAM has to be used. Here, we need to define the area of cross section manually. In most cases, the cross section is simple. So using PBEAML is sufficient. As for the second query, you can define the bolt axis direction using (N1, N2, N3, B) option. Then it does not have to be parallel/perpendicular to any global axes. Any vector can be defined by selecting nodes. I hope this information helps!
Hi... While creating the rigid you selected only the outer nodes of the hole...But usually we will have a washer in between the bolt and the mating component... In order to represent the washer we need to select another layer of nodes adjacent to it right?
I have problem related to it i have a box which i modelled as conmass at the centre of RB3 elements but the when i m applying the load the the stresses are coming very high but when i changed to RB2 the stresses near the bolting points became 1/5 , i am not able to understand why the variation is coming this much
Hey Pedro, all the 3 methods that I demonstrated can be used for shell as well as solid parts. If I want accurate results, I would definitely go for the beam type bolt. If the bolted region is not of prime importance, rigid bolt would suffice. Cheers :)
@@Aeroswap Dear friend, i hope you're well! I have a question regardless from bolt creation. How can I create a section which is not already defined in "Hyperbeam" selection? For example "Aluminum Rexroth Profile". How can I draw it manually? Thanks in advance!
Hey Furkan, I'm doing well. I hope you are too! It is possible to draw custom cross-sections in the Hyperbeam tool itself. There are options provided to draw the section or import it from an external file. The only change will be the card image of property. In case of custom section, you will have to use PBEAM instead of PBEAML.
Also something that is somewhat not shown in the vid is that there are 3 different cases /models that need to be saved separately correct? Also how do you load the results of them in parallel in hyperview ? ( a nice small vid clarifying that would be useful) thank you
Hi Chris. To answer your first question: yes, you save the three models and their respective .fem file. As for the Hyperview in multiple windows, in the top menu icons select the "page window layout" button (its icon is a white box) and there select the desired layout. Then, you click on the graphics window space to activate it. After that, load your animation as usual and do the same for each window. Finally, if you want to synchronize the view, select the "synchronize windows" button
Hi, Thanks for the video again. I got one error while applying the beam property as below. *** Error #1479 *** in the input data: Incorrectly formatted numeric data in field 9. 7890:PBEAML, 2, 1, , , , , , >ERROR< I checked the .fem file and the erroneous input was made in PBEAML line as above. I could resolve this error by unapplying the 'Beam Section' made by HyperBeam and then manually input the cross section info as ROD, DIM1A : 6. But the plate 'flies up' even with very small force input. Can I resolve the error while I keep using the HyperBeam menu?
Hello! It does not matter whether the components being joined are 2D or 3D. The bolt connection can be made using the same method for any type of component. As bolt connectors are usually used for joining sheet metal and BIW parts, I used a 2D mesh. Nevertheless, feel free to experiment this method on 3D components. Hope this answers your question!
@@Aeroswap hi, for 3D parts, if i choose bolt and rbe2 method, so how to define dependent nodes of rbe2 ? It should be only the upper and lower position of 3D parts or should be inner surface hole of each 3D part ?
I would go with the whole inner surface. However, it comes down to your perspective about the analysis. You can go with whichever method you feel is more realistic!
@@Aeroswap a real past industrial projects which you may have handled eg. Automotive parts or any other. Tell what was the project about, from where we should take lead, what kind of results we should expect, after getting results is it matches our expectations. While giving final report what type format and what details should be mentioned in report. Thanks for reply.
@@Aeroswap Sir, I watched the video but I think that the concept is different, I want to create element such like that the stiffness is zero in compression
In a simplified case, riveted joints can be considered as point connectors between the two components. Hence, they can be modeled similar to spot welds with some modifications in the element type and property.
Instead of doing all this why dont you use the Bolt connectors from the 1d>connectors> bolt create which will save your modelling time. you have various configurations on the same panel and connector browser
Yes indeed we can use that method. But in some cases where the geometry is complex, the automatic bolt creation fails. I have had this issue many times. Nevertheless, thanks for mentioning the automatic method! Will definitely be helpful for everyone.
It never fails you have multiple settings which can be tweaked based on your hole diameter inside the bolt options panel so that you can create it easily Also many OEM prefer the bolt panel configuration method since it supports multiple use cases n the time to create for a BIW assembly is very easy
![Hypermesh Optistruct Tutorial [Global-Local Analysis]](http://i.ytimg.com/vi/th4ahPCDIYA/mqdefault.jpg)
![Hypermesh Optistruct Tutorial [Global-Local Analysis]](/img/tr.png)
![Topology Optimization using Hypermesh [Optistruct Tutorial]](http://i.ytimg.com/vi/-Uw7YWTy5so/mqdefault.jpg)
![Hypermesh Weld Connectors [Spotweld & Seamweld]](/img/n.gif)
Holding your hand to learn hypermesh
Great videos always!! I often use RBE2 + Beam idealization to idealize my models and also size the bolts by extracting gpforces of the beam elements (tension / compression). But this obviously cause stress concentrations on the RBE2 dependent nodes (bolt heads or flanges overly idealized) since it blocks all the dofs hence no bolt shear is considered. Thus I often ignore the stress concentrations and make notes of this. You could also hand-calculate the bearing stress of the plates based on the gpforces of the beam elements. On the other hand, RBE3 does not block any dofs on the independent nodes since it only transfer loads, meaning there is no bolt heads or flanges stiffness considered. Also this is why you would likely see less stress concentration effects when using RBE3. I can’t answer which method is correct or wrong, but every analyst should decide based on the level of interest. The best way is to run a nonlinear contact with a bolt idealized with solid elements but it is super time consuming.
Agreed, as no model of 1D bolt can be regarded as perfect, it's upto the analyst to decide based on the requirements.
Right! Gpforce can be used to extract tension/compression. I have used gpforce to extract nodal force values at specific node locations in the model but didn't know it also works for Beam elements.
Thanks for the info!
Aeroswap your tutorials are the ones that are often used in industry and I really hope more people will subscribe your channel. 👍👍👍
Thanks Ken! I hope so too.
Great Video, Very detailed and your explanation is on point . Looking forward for your videos .
Thank you :)
Hey Prithvi, I'm glad you liked the video :)
Hello. Very good explanation in all your videos. Request you to share downloadable Files for better understanding and practise.
Great video👍
Helped a lot🙌
I have a question, why we always prefer to use RBE2 over RBE3 around hole, wherever we've to apply the constraints or forces, just like we saw in the case of static structural analysis(in previous videos) of knuckle, we have make use of RBE2 elements around hole/mounting and accordingly we have applied constraints & forces, we would have prefer RBE3 since it distribute forces around the connected nodes.
Thank you and looking forward to your reply.
Hi Shashwat,
Good question!
The location of independent and dependent nodes is reversed on case of RBE3. This can cause errors in the analysis if the RBE3 element is not defined correctly.
As a general practice to avoid complexities, RBE2 is used for load application and RBE3 is used for mass addition and bolted joints.
I hope this answers your question :)
@@Aeroswap Thank you
As usual great work man, keep it up. Pls make videos on advanced shell meshing.
Thanks! Will work on it 👍🏻
Very good video. But it is better if you can compare the results with e xperimental data or analytical calculation to find the best accuracy model.
And could you please share the methods to model the bolt between 2 3D parts ?
Thank you.
I have already posted tutorials about 1D as well as 3D bolt modelling. Please check the 'Optistruct Tutorials' playlist to find these videos.
Great work !!!!!
Thank you :)
Great work bro.. It would be helpful if you provide theories like differences in bolts, beams and rods.. And why rigids has no properties..
Thank you Umesh. Basically, we have have any required property and material for a beam bolt. The method to create the bolt is exactly the same as I demonstrated.
Feel free to experiment with different materials and cross-sections.
As for rigids, they are non-deformable 1 dimensional entities.
> 1 dimensional so no cross-section (property)
> Non- deformable so no material
I will work on a separate video to explain beam, and rod differences. Thanks for the suggestion!
Thanks for response, by the way you are pretty straight to topics where there is no introduction of self and no subscribe , no share kind of thing.. keep doing the videos...
@@Aeroswap But as we know RBE3 elements are less stiffer and therefore can be deformable then why don't we assign material to them?
Thank you for your tutorial videos on hypermesh. Just want to ask the 3rd method you told can it be used for multiple plates like 4 plates are their and a single bolt is passing through. Waiting for your answer.
Hi Miheer,
Good question. Yes, this method can be used to create a bolted joint between more than 2 plates. However, certain modifications are required. If rigids are created only on the lower and upper plates, there will be no contact between bolt and the middle plate. To avoid this, a rigid must also be created on the middle plate.
I hope this helps.
@@Aeroswap thankyou with this I will also request you to make a video on leaf spring suspension if possible.
thank you so much for your work
Thanks for watching!
I really love watching ur videos , it's like cup of tea for me daily , I want to work for some product based companies
Please help me out
Thanks Amogh, I'm glad you liked the videos :)
If you need any help, feel free to reach out via email. My contact details are provided in the 'About' section of this channel.
Great video
Hello bro, your connectors video helped a lot!!! But I have a doubt regarding bolt connectors. If we want to fasten more than 2 components together with a single bolt, do we have to apply RBE3 elements only on the top and bottom components and not on the middle components? Please explain.
Good question!
In that case, you can either create a 3D solid bolt with contacts or a 2-stage 1D bolt which connects all the 3 components.
@@Aeroswap Actually I don't know how to create 3D solid bolts. Have you created any video on it.. Or can you provide any other source to study?
Also can you please tell if we can create U-Bolts in hypermesh. If not, then what type of fasteners can we use in place of it?
Solid bolt cannot be modelled in Hypermesh directly. You have to import the bolt CAD and specify the pretension and contact settings to get the bolted joint properties as required!
Great! What if we use rbe3 alone by selecting all the circular edge nodes of both the plates? What's the result?
Good question! In that case, you will observe very high deformations as RBE3 does not work like RBE2.
As the locations of dependent and independent nodes are interchanged, the behaviour changes drastically.
The plate on which force is applied will practically 'fly away' with infinite deformation and the RBE3 element will be seen to stretch accordingly.
It's an interesting thing to watch, feel free to setup this case and observe the results.
@@Aeroswap hey man, very informative video.
I tried this direct RBE3 like RBE2 and the part did 'fly away' with large deformation.
my question is, I tried to connect two RBE3 with the CBEAM as you have shown above, but still one of my part flies away with large deformation ?
Can you think of a reason why ? Please help.
Hi Suyog,
Please check if the CBEAM is exactly attached to the center node of each RBE3 element. Also check if a material and property is assigned to the CBEAM.
This should resolve the error.
@@Aeroswap Hi, thank you for the quick reply.
Yes the CBEAM is attached exactly on the two RBE3 points.
However I would like to check these two points with you :
(1) I used property as PBEAM and not as PBEAML, because then i was getting this error :
*** ERROR # 1479 *** in the input data: Incorrectly formatted numeric data in field 9
[there is a random "+" in field 9]
can that be the reason ?
(2) also in above example, the bolt axis is perpendicular to x axis, so that's good.
but in my case, the bolt axis is not perpendicular to any of the three axis
does the axis have to be perpendicular and if yes, then how do I define it in my example ?
Thank you once again for your help, I tried looking for these questions, but I could not get much information on google for these.. :)
Hi Suyog,
PBEAM and PBEAML have some inherent differences. In PBEAML, we can define the cross section using standard geometrical shapes (example : square, circle). We do not have to enter the area of cross section as it is directly calculated based on these geometrical shapes.
On the other hand, PBEAM is used to define a much more complex cross section. If the cross section cannot be created by standard shapes, PBEAM has to be used. Here, we need to define the area of cross section manually.
In most cases, the cross section is simple. So using PBEAML is sufficient.
As for the second query, you can define the bolt axis direction using (N1, N2, N3, B) option. Then it does not have to be parallel/perpendicular to any global axes. Any vector can be defined by selecting nodes.
I hope this information helps!
Hi... While creating the rigid you selected only the outer nodes of the hole...But usually we will have a washer in between the bolt and the mating component... In order to represent the washer we need to select another layer of nodes adjacent to it right?
There are multiple ways to model the bolted joint. Feel free to adopt whichever method you feel is sufficient to get the physics right!
@@Aeroswap okay. Thank you. Can you please make a video on 1d elements and the effects if they are not properly used.
Thanks for the suggestion. I will work on this topic soon!
I have problem related to it i have a box which i modelled as conmass at the centre of RB3 elements but the when i m applying the load the the stresses are coming very high but when i changed to RB2 the stresses near the bolting points became 1/5 , i am not able to understand why the variation is coming this much
Great video!! thanks a lot! What would you use if you were to bolt 2 solid parts? Cheers from Brazil
Hey Pedro,
all the 3 methods that I demonstrated can be used for shell as well as solid parts. If I want accurate results, I would definitely go for the beam type bolt.
If the bolted region is not of prime importance, rigid bolt would suffice.
Cheers :)
@@Aeroswap How should I when there is one bolt connecting 3 components? Thanks for the reply!!
Better to go for 3D bolt components in that case!
1D rigids cannot be used to link 3 components at the same time.
Great video! I have a question; how do you calculate the "required torque value" for the bolt?
Hello,
Torque values must be determined by hand calculations to get proper results.
@@Aeroswap Dear friend, i hope you're well! I have a question regardless from bolt creation. How can I create a section which is not already defined in "Hyperbeam" selection? For example "Aluminum Rexroth Profile". How can I draw it manually?
Thanks in advance!
Hey Furkan,
I'm doing well. I hope you are too!
It is possible to draw custom cross-sections in the Hyperbeam tool itself. There are options provided to draw the section or import it from an external file.
The only change will be the card image of property. In case of custom section, you will have to use PBEAM instead of PBEAML.
@Aeroswap If there is friction between the bolt and the plate. Can i assign friction co-efficient after doing this process?
Also something that is somewhat not shown in the vid is that there are 3 different cases /models that need to be saved separately correct? Also how do you load the results of them in parallel in hyperview ? ( a nice small vid clarifying that would be useful) thank you
Hi Chris. To answer your first question: yes, you save the three models and their respective .fem file. As for the Hyperview in multiple windows, in the top menu icons select the "page window layout" button (its icon is a white box) and there select the desired layout. Then, you click on the graphics window space to activate it. After that, load your animation as usual and do the same for each window. Finally, if you want to synchronize the view, select the "synchronize windows" button
@@jaimecardenascervantes9908 i will give it a shot thanks
Hi, Thanks for the video again. I got one error while applying the beam property as below.
*** Error #1479 *** in the input data:
Incorrectly formatted numeric data in field 9.
7890:PBEAML, 2, 1, , , , , , >ERROR<
I checked the .fem file and the erroneous input was made in PBEAML line as above.
I could resolve this error by unapplying the 'Beam Section' made by HyperBeam and then manually input the cross section info as ROD, DIM1A : 6. But the plate 'flies up' even with very small force input.
Can I resolve the error while I keep using the HyperBeam menu?
can we use RBE2 and RBE3 for nonlinear analysis or does it have limitations?
Hi Neeraj, you can use RBE2 as well as RBE3 in nonlinear analysis. There will not be any issues with that.
Hey!
In this tutorial you connect shell (2D) components , how is it if i want to connect 3D components ?
Hello!
It does not matter whether the components being joined are 2D or 3D. The bolt connection can be made using the same method for any type of component.
As bolt connectors are usually used for joining sheet metal and BIW parts, I used a 2D mesh. Nevertheless, feel free to experiment this method on 3D components.
Hope this answers your question!
@@Aeroswap hi, for 3D parts, if i choose bolt and rbe2 method, so how to define dependent nodes of rbe2 ? It should be only the upper and lower position of 3D parts or should be inner surface hole of each 3D part ?
I would go with the whole inner surface. However, it comes down to your perspective about the analysis. You can go with whichever method you feel is more realistic!
@@Aeroswap thanks, but i want to go with the most realistic method :D
Bro can you make videos on some industrial projects on hyperworks. It's ok if video is lengthy.
Can you elaborate more on what you mean by industrial projects ?
@@Aeroswap a real past industrial projects which you may have handled eg. Automotive parts or any other. Tell what was the project about, from where we should take lead, what kind of results we should expect, after getting results is it matches our expectations. While giving final report what type format and what details should be mentioned in report.
Thanks for reply.
Thanks for the suggestion. I will see what I can do :)
@@Aeroswap 🙏
Make a video of random vibration analysis with proper explaination.
Thanks for the suggestion. I will work on this topic soon!
Can you explain difference between direct frequency analysis and modal frequency analysis???
i tried your method but when i used PBEAML it gived me error but when i used PBEAM i had a results ?
thanks
Is there any way to create tension only spring elements in hypermesh?
Yes, please watch the recently posted bolt pretension tutorial on this channel.
@@Aeroswap Sir, I watched the video but I think that the concept is different, I want to create element such like that the stiffness is zero in compression
Have you tried to create an axial joint? In joints, we can set the desired stiffness for all applicable degrees of freedom.
@@Aeroswap No sir,till now I have not tried with axial joint in hypermesh..
@@Aeroswap if it is possible kindly make a video on cgap elements
Hi and thank you for the interesting vids - i am getting an error :
'PBEAML 2 1 +'
*** ERROR # 1479 *** in the input data:
Incorrectly formatted numeric data in field 9.
can you assist ?
Thank you
how to model riveted joints in hypermesh
In a simplified case, riveted joints can be considered as point connectors between the two components. Hence, they can be modeled similar to spot welds with some modifications in the element type and property.
@@Aeroswap what element types and property needs to be change, kindly tell
Instead of doing all this why dont you use the Bolt connectors from the 1d>connectors> bolt create which will save your modelling time. you have various configurations on the same panel and connector browser
Yes indeed we can use that method. But in some cases where the geometry is complex, the automatic bolt creation fails. I have had this issue many times.
Nevertheless, thanks for mentioning the automatic method! Will definitely be helpful for everyone.
It never fails you have multiple settings which can be tweaked based on your hole diameter inside the bolt options panel so that you can create it easily
Also many OEM prefer the bolt panel configuration method since it supports multiple use cases n the time to create for a BIW assembly is very easy
A step ahead in latest version of HM we now have attachments concept for creating bolt connectors which is also a useful method
Okay! In that case, I will make a separate video about that. Thanks for the info.
By latest version, do you mean Hyperworks X ?
i have a job for you , if you have a time we can speak about it ?
Hi Sami,
Please contact me via email. My email address is provided in the 'About' section of this channel.
Thanks.