follower force
Can someone help me to simulate a beam subjected to non-conservative follower force , I have found a video on youtube about a beam subjected to a follower force but it was not clear , he started the explanation after he had created a beam with options like (RBE2...) , here you the video on youtube
I tried many times to create that beam like the video but I was not abe. for example , when he applied the force, the beam already contains nodes and that cross on its top !
Answers
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you should start from the CAD geometry or try to draw the geometry in HM, first of all.
Once you have the geometry, you can start building the 3D mesh (using tetramesh or solidmap, depending on the complexity).
The 'x' that you see is a rigid element (RBE2 in OptiStruct), that can be created in 1D>rigids
once you have the mesh, amterials, and properties, you create a load collector, and going in forces you
For the follower force, you will create a force otf type FORCE1 and select 2 nodes on your mesh as reference for the direction.
So once you enable PARAM,FFLOWER,YES, your force will follow these 2 nodes.
This is all covered in the documentation unbder the tutoria for OptiStruct
OS-T: 1510 Follower Loads, Nonlinear Adaptive Criteria, and Nonlinear Intermediate Results
<?xml version="1.0" encoding="UTF-8"?>
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Altair Forum User said:
thank you so much for your response . the only thing which confused me in this tutrial is the mesh and how to select nodes , I just want to get to know how to create that beam . since I am totoally beginner at this software I was not able to make that beam with meshing .
You should start from the CAD geometry or try to draw the geometry in HM, first of all.Once you have the geometry, you can start building the 3D mesh (using tetramesh or solidmap, depending on the complexity).
The 'x' that you see is a rigid element (RBE2 in OptiStruct), that can be created in 1D>rigids
once you have the mesh, amterials, and properties, you create a load collector, and going in forces you
For the follower force, you will create a force otf type FORCE1 and select 2 nodes on your mesh as reference for the direction.
So once you enable PARAM,FFLOWER,YES, your force will follow these 2 nodes.
This is all covered in the documentation unbder the tutoria for OptiStruct
OS-T: 1510 Follower Loads, Nonlinear Adaptive Criteria, and Nonlinear Intermediate Results
<?xml version="1.0" encoding="UTF-8"?>
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Can you walk me through the steps of making that beam with mesh !!
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Altair Forum User said:
you should start from the CAD geometry or try to draw the geometry in HM, first of all.
Once you have the geometry, you can start building the 3D mesh (using tetramesh or solidmap, depending on the complexity).
The 'x' that you see is a rigid element (RBE2 in OptiStruct), that can be created in 1D>rigids
once you have the mesh, amterials, and properties, you create a load collector, and going in forces you
For the follower force, you will create a force otf type FORCE1 and select 2 nodes on your mesh as reference for the direction.
So once you enable PARAM,FFLOWER,YES, your force will follow these 2 nodes.
This is all covered in the documentation unbder the tutoria for OptiStruct
OS-T: 1510 Follower Loads, Nonlinear Adaptive Criteria, and Nonlinear Intermediate Results
<?xml version="1.0" encoding="UTF-8"?>
Would please help me create that beam with RBE2 option and how to exactly mesh it, I really want a tutorial to follow it . through the document you mentioned I was able to create NLPARM ,NLOUT, Follower YEs , but I was not able to create such a beam with RBE2 and mesh , I specifically want a straight beam under a follower force ( cylindrical section or rectangular section , I wil try with both . honestly I am going to write an article in the field of robotics and compare this simulation to the theory of flexible robots , I will write your name in my article in the second or third position .
I am waiting for your answer adriano . it would a great help , you know it has been such a long time when I have started with follower force , going through solidworks , anysys..etc and finally Hypermesh optistuct proved the right software to do it .
thank you so much in advance adriano .
waiting for you answer0 -
please, take a look at this video at youtube..it is very similar.
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Altair Forum User said:
please, take a look at this video at youtube..it is very similar.
I will go through it , thank you
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Altair Forum User said:
I will go through it , thank you
Altair Forum User said:please, take a look at this video at youtube..it is very similar.
wow , it really worked out dear. you do not know how I am thankful. Now I have to do the same thing on a cylindrical beam ( circle section). is it the same thing !! how can I create nodes like this video with a cylindrical beam !!
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Hi,
you should take the basic HM training class, as it can help you a lot to improve your skills.
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Probably your local Altair support provide some videos or trainings, or even in Altair University website.
For performing exactly the same thing with a cylindrical beam, you just need to create a cylinder from the beginning.
For creating a cylinder in HM, you need first the center point of one side of the cylinder, and another point to define the axis of it.
Start creating the nodes from the 'nodes' panel, giving the coordinates.
<?xml version="1.0" encoding="UTF-8"?>
Having the nodes, go to the 'solids' panel, select 'Full Cylinder' and then select the bottom center node, and the other node to give the axial direction.
Type the radius and Height and there you go. You will have the cylinder ready to be meshed and perform your analysis.
<?xml version="1.0" encoding="UTF-8"?>
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Altair Forum User said:
Hi,
you should take the basic HM training class, as it can help you a lot to improve your skills.
Probably your local Altair support provide some videos or trainings, or even in Altair University website.
For performing exactly the same thing with a cylindrical beam, you just need to create a cylinder from the beginning.
For creating a cylinder in HM, you need first the center point of one side of the cylinder, and another point to define the axis of it.
Start creating the nodes from the 'nodes' panel, giving the coordinates.
<?xml version="1.0" encoding="UTF-8"?>
Having the nodes, go to the 'solids' panel, select 'Full Cylinder' and then select the bottom center node, and the other node to give the axial direction.
Type the radius and Height and there you go. You will have the cylinder ready to be meshed and perform your analysis.
<?xml version="1.0" encoding="UTF-8"?>
Thank you so so much , I made it. I will try to apply a follower force on it now. I know how to do it based on the help you provided me with the last time. I will try it now
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everything worked properly but when I applied follower force , No error found but the beam does not show any affect and results were 0
<?xml version="1.0" encoding="UTF-8"?>
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Here youare the beam file with everything defined but it does not bend or move or show any affect by the applied force !!
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Altair Forum User said:
Thank you so so much , I made it. I will try to apply a follower force on it now. I know how to do it based on the help you provided me with the last time. I will try it now
Altair Forum User said:Hi,
you should take the basic HM training class, as it can help you a lot to improve your skills.
Probably your local Altair support provide some videos or trainings, or even in Altair University website.
For performing exactly the same thing with a cylindrical beam, you just need to create a cylinder from the beginning.
For creating a cylinder in HM, you need first the center point of one side of the cylinder, and another point to define the axis of it.
Start creating the nodes from the 'nodes' panel, giving the coordinates.
<?xml version="1.0" encoding="UTF-8"?>
Having the nodes, go to the 'solids' panel, select 'Full Cylinder' and then select the bottom center node, and the other node to give the axial direction.
Type the radius and Height and there you go. You will have the cylinder ready to be meshed and perform your analysis.
<?xml version="1.0" encoding="UTF-8"?>
would please hav a look on the whole file , it works properly but the beal does not bend or show any sign of displacement !!
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Hi again,
your model does not perform as expected because you have applied both forces and constraints(SPC) in free temp nodes (the ones that you've used for creating the geometry).
The temp nodes were not attached to your mesh, thus they do not transmit anything to your structure.
In order to connect them, i've created a couple rigid elements (1d>>Rigids>>RBE2) in both ends.
I attached the model with RBE2's, but it is not converging for your loading.
Your loading needs to be reviewed as you have applied only a normal compressive loading.
I don't know what you're trying to accomplish here, but i would review these loads. Also depending on your targets, NL material could also be considered.
Please take a look also at Altair free e-books at Altair University. They might help with some modelling tips.
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Altair Forum User said:
Hi again,
your model does not perform as expected because you have applied both forces and constraints(SPC) in free temp nodes (the ones that you've used for creating the geometry).
The temp nodes were not attached to your mesh, thus they do not transmit anything to your structure.
In order to connect them, i've created a couple rigid elements (1d>>Rigids>>RBE2) in both ends.
I attached the model with RBE2's, but it is not converging for your loading.
Your loading needs to be reviewed as you have applied only a normal compressive loading.
I don't know what you're trying to accomplish here, but i would review these loads. Also depending on your targets, NL material could also be considered.
Please take a look also at Altair free e-books at Altair University. They might help with some modelling tips.
I would like to simulate a column subjected to a follower force which means the force keeps moving as the beam bends ( force normal to the beam along the bending of the beam)
<?xml version="1.0" encoding="UTF-8"?>
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Altair Forum User said:
Hi again,
your model does not perform as expected because you have applied both forces and constraints(SPC) in free temp nodes (the ones that you've used for creating the geometry).
The temp nodes were not attached to your mesh, thus they do not transmit anything to your structure.
In order to connect them, i've created a couple rigid elements (1d>>Rigids>>RBE2) in both ends.
I attached the model with RBE2's, but it is not converging for your loading.
Your loading needs to be reviewed as you have applied only a normal compressive loading.
I don't know what you're trying to accomplish here, but i would review these loads. Also depending on your targets, NL material could also be considered.
Please take a look also at Altair free e-books at Altair University. They might help with some modelling tips.
wow than you so much , it is working , would you please show me what you have done to make it work !!
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How did you attach (RBE2's ) can you show me through pictures , I mean the steps you performed to create RBE2 and the exact changing you did to make it work !!
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Altair Forum User said:
Hi again,
your model does not perform as expected because you have applied both forces and constraints(SPC) in free temp nodes (the ones that you've used for creating the geometry).
The temp nodes were not attached to your mesh, thus they do not transmit anything to your structure.
In order to connect them, i've created a couple rigid elements (1d>>Rigids>>RBE2) in both ends.
I attached the model with RBE2's, but it is not converging for your loading.
Your loading needs to be reviewed as you have applied only a normal compressive loading.
I don't know what you're trying to accomplish here, but i would review these loads. Also depending on your targets, NL material could also be considered.
Please take a look also at Altair free e-books at Altair University. They might help with some modelling tips.
would you please show me how did you create RBE2 and that spider-like on both sides of the beam . explain to me through pictures as you did before. I am very thankful.
waiting for your answer.<?xml version="1.0" encoding="UTF-8"?>
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You should watch this video
I recommend you to go through the trainings at Altair University as they cover the basics of HM pretty well.
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Altair Forum User said:
You should watch this video
I recommend you to go through the trainings at Altair University as they cover the basics of HM pretty well.
God bless you , I managed to create it . I can not really learn hypermesh , I just use it for a specific reason , the only thing which concerns me is the follower force . none of the existing software allow you to apply a follower force except ' hypermesh' , this is why I am trying to use it. thank you so so much .
You seem an expert in this software, I wish you can squeeze me in and figure out how to apply a follower force on a cylindrical beam. it has been 2 years since I started workin on this issue . it is a part of my thesis of doctorate . I will write you in my thesis . you really opened doors to me through your comments . thank you so much .
I have already simulate a continuum robot with matlab and I am trying to compare results with another software. its backbone is a cylindircal beam .....0 -
have you tried linear buckling as a initial guess of buckling load?
this shoud be your first approach, probably.
good luck in your thesis.
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Altair Forum User said:
have you tried linear buckling as a initial guess of buckling load?
this shoud be your first approach, probably.
good luck in your thesis.
Buckling has nothing to do with non-conservative follower force. I have delibertately chosen this type of force because the continuum robot I am working on is assimulated into a circular beam with disks and cables and the force actuatted on the cables is similar to a follow'er force, it keeps moving as the backone of the robot bends . actually , the force must be applied on one of the three cables but I just want to start with a beam . by the way can I draw this robot and mesh it in hypermesh!!! . it seems awfully coomplicated to me to do so . the blue beam is the backbone of he robot , circular shapes are the disks and three cables pass through holes in the disks.
<?xml version="1.0" encoding="UTF-8"?>
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you should probably work with a mixed 1D/2D model in HM/OptiStruct for that. Shell elements for the disks and beam elements for the cables.
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Altair Forum User said:
you should probably work with a mixed 1D/2D model in HM/OptiStruct for that. Shell elements for the disks and beam elements for the cables.
Can you please recommend any tutorial on how to do that and what do you think if I create that robot on solidworks then import it to hypermesh !!
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the same video i've shared before for rigids shows how to create beam elements.
you should find something in Altair University or their youtube channel.
for your model, having only the disks geometry modelled into the CAD is enough, including the points for attaching the beams.
In HM you will create first the 2D mesh, using the fixed points as reference.
I'm attaching a very basic video as well, but again, go after some training material in Altair University.
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Altair Forum User said:
the same video i've shared before for rigids shows how to create beam elements.
you should find something in Altair University or their youtube channel.
for your model, having only the disks geometry modelled into the CAD is enough, including the points for attaching the beams.
In HM you will create first the 2D mesh, using the fixed points as reference.
I'm attaching a very basic video as well, but again, go after some training material in Altair University.
Would you be so kind as to let me know how did you create these circles at first , I promise I will go through training for hypermesh !!!! I spend much time working on it through soldiworks but it did not work but based on that video , hypermesh can properly do it . again I would be so grateful . honestly you helped me a lot . thank you so much .
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if you have solidworks, just draw these in SW and then import them to HM. It would save you some time.
In HM follow the attached video.
I promise I will go through training for hypermesh !!!!
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Altair Forum User said:
the same video i've shared before for rigids shows how to create beam elements.
you should find something in Altair University or their youtube channel.
for your model, having only the disks geometry modelled into the CAD is enough, including the points for attaching the beams.
In HM you will create first the 2D mesh, using the fixed points as reference.
I'm attaching a very basic video as well, but again, go after some training material in Altair University.
Altair Forum User said:https://community.altair.com/community?id=community_question&sys_id=3576843a1b2bd0908017dc61ec4bcb64 1 hour ago, Adriano A. Koga said:the same video i've shared before for rigids shows how to create beam elements.
you should find something in Altair University or their youtube channel.
for your model, having only the disks geometry modelled into the CAD is enough, including the points for attaching the beams.
In HM you will create first the 2D mesh, using the fixed points as reference.
I'm attaching a very basic video as well, but again, go after some training material in Altair University.
Would you be so kind as to let me know how did you create these circles at first , I promise I will go through training for hypermesh !!!! I spend much time working on it through soldiworks but it did not work but based on that video , hypermesh can properly do it . again I would be so grateful . honestly you helped me a lot . thank you so much .
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Altair Forum User said:
if you have solidworks, just draw these in SW and then import them to HM. It would save you some time.
In HM follow the attached video.
and how can we create that cylindrical beam which goes through the center of the four disks you created, would you please help me create that robot and try to apply a force on one of the cables and see the bending of that robot. help me with video tutorials as you did before. Thank you so so much Mr adriano.
it must be a hole in each disk to place the cylindical beam.<?xml version="1.0" encoding="UTF-8"?>
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this is my last video for you.
now go and give it a try, and look after some training materials out there.
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Altair Forum User said:
this is my last video for you.
now go and give it a try, and look after some training materials out there.
Oki , thank you so much
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