Beam error
Altair EmployeeHi
I am trying to use contact with beam elements and I am getting the following error. Could anyone tell me what the error is?
ERROR ID : 223
** ERROR IN BEAM DEFINITION
DESCRIPTION :
IN BEAM ID=78, N1 and N3 HAVE SAME LOCATION
SOLUTION :
CHANGE N1 OR N3 COORDINATES
Answers
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Maybe direction node is concide to n1
Try update direction node of the beam
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Hi Kartik,
This seems an error with the beam orientation.Please recreate/update the beam elements in the model and try running again.
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Altair Forum User said:
Hi Kartik,
This seems an error with the beam orientation.Please recreate/update the beam elements in the model and try running again.
I have recreated the whole structure again but the error still pops. I cannot understand what I am doing wrong ??
while creating I first drew sketches of the beam and the pulley.
Then I did a line mesh of the same.
I did a auto selection of the orientation. Is this wrong??
Also is there a tutorial for the same
<?xml version="1.0" encoding="UTF-8"?>
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Hi Kartik,
This seems like an orientation error for the pulley elements created. Can you try updating the pulley elements with selecting orientation as screen normal option.
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Hi George P Johnson,
I have solved the error by remeshing the pulley. But now the contact doesn't seem to work. I am sharing the pic of the model.
Also it is a edge edge to contact as both are 1D mesh so I have selected a type 11 contact. Why isn't the contact working?
Could you help?
yours sincerely,
Kartik Kanugo
<?xml version="1.0" encoding="UTF-8"?>
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Hi Kartik,
You cannot simulate a belt-pulley like simulation with this modelling approach. For the beam elements one end is fixed and at the other end load is applied which will make the 'pulley' component unstable and the belt component will just move in Y direction. Please remodel with Type 12 spring (Pulley Spring Property Set) with which you can simulate the same effect.
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Altair Forum User said:
Hi Kartik,
You cannot simulate a belt-pulley like simulation with this modelling approach. For the beam elements one end is fixed and at the other end load is applied which will make the 'pulley' component unstable and the belt component will just move in Y direction. Please remodel with Type 12 spring (Pulley Spring Property Set) with which you can simulate the same effect.
Hi George P Johnson,
I have a few queries, the files have uploaded are not complete I have a few doubts in them.
1) Initially I created the whole setup again. I used line mesh with spring type elements. (Is this correct ?)
2) Contact I am unable to give due to some direction error in 1D element.
3) I have studied about the pulley spring element added a few parameters by what I understood. Accordingly is it that the rope will be modeled with beam elements and only pulley with spring element and in this case I wont apply the non linear stiffness (H = 1) (as in the model attached). ?
yours sincerely,
kartik kanugo
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Hi
Previously, as mentioned I changed the rope to int beam element and left the pulley with spring element.
I get the below mentioned error
** ERROR ERROR ID : 760TRAPPEDOut of the 2 previously uploaded. Could you help me add contact between the pulley and rope to just simulate it?I Have already placed all the Boundary conditions and kept.Also is the problem there in my initial mesh?yours sincerely,kartik kanugo0 -
Hi,
With /PROP/TYPE12 type spring we are actually replacing the pulley. It has to be defined using 3 nodes.
With this loadcase of initial velocity, the rope will be simply dragged in Y direction rather than getting a 'rope-pulley' effect. And it will be difficult to define a contact in such case.
I would recommend to model the rope with beam elements and the pulley with Type 12 spring.
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Altair Forum User said:
<?xml version="1.0" encoding="UTF-8"?>
Hi,
With /PROP/TYPE12 type spring we are actually replacing the pulley. It has to be defined using 3 nodes.
With this loadcase of initial velocity, the rope will be simply dragged in Y direction rather than getting a 'rope-pulley' effect. And it will be difficult to define a contact in such case.
I would recommend to model the rope with beam elements and the pulley with Type 12 spring.
in the above case, You mean to say I create a single rope with a bend and no pulley.
then at the bend select 3 nodes and give spring pulley property?
Also in the picture shown should I do 1D mesh will all spring elements..
or for the rope part bar elements and the pulley region spring elements
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Hi,
Yes, no pulley is modeled and using 3 nodes model the spring with Type 12 property.
I recommend to model the rope with beam elements. Please try with the same.
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Altair Forum User said:
Hi,
Yes, no pulley is modeled and using 3 nodes model the spring with Type 12 property.
I recommend to model the rope with beam elements. Please try with the same.
ya I got the whole idea now but in this case I cannot measure stress in the pulley?
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Hi,
Normally in spring elements we will check for spring element forces.
You can create an output block for the spring element and you can output the default variables (Forces, Internal Forces...etc) in the time history file.
Please go through /TH/SPRING in the Help Menu where you can get more details.
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Hi
I have created the structure required but I am still having an error. If you observe the h3d file the beam3N and spring3n files are getting detached.
in the pic you can see the beam breaking of from pulley.
kindly tell me where I went wrong. I also gave a boundary condition to the pulley.
I need to observe shockwave that propagates in the structure.
yours sincerely,
kartik
<?xml version="1.0" encoding="UTF-8"?>
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Hi,
In springs option use spring3 menu and select the 3 nodes for creating the pulley spring. I'm reattaching the file which I have shared you earlier on pulley type spring.
Create imposed displacement load collector instead of initial velocity and try running.
<?xml version="1.0" encoding="UTF-8"?>
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Altair Forum User said:
Hi,
In springs option use spring3 menu and select the 3 nodes for creating the pulley spring. I'm reattaching the file which I have shared you earlier on pulley type spring.
Create imposed displacement load collector instead of initial velocity and try running.
<?xml version="1.0" encoding="UTF-8"?>
yep i used this file has reference but for my problem i cannot change the initial velocity part.
because we are doing a practical test and it only has initial velocity.
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Hi,
We normally apply initial velocity load cases for crash/impact/drop cases. This is a typical imposed load condition.
If you are particular on initial velocity, then you can try with the same.
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Altair Forum User said:
Hi,
We normally apply initial velocity load cases for crash/impact/drop cases. This is a typical imposed load condition.
If you are particular on initial velocity, then you can try with the same.
I have created it but i am getting the following errors
One more thing in the file i have created earlier. I have created more than 3 nodes for the pulley is it necessary to have only 3 nodes for the pulley?
-- ELEMENT INITIALIZATION 2 ERROR(S) | |
| | | |
| | | |
| |--- 1 ERROR ID : 59 | |
| | ** ERROR IN PROPERTY/ELEMENT DEFINITION (NUMBER) | |
| | | |
| |--- 1 ERROR ID : 61 | |
| | ** ERROR IN MATERIAL/ELEMENT DEFINITION (NUMBER)ERROR ID : 59
** ERROR IN PROPERTY/ELEMENT DEFINITION (NUMBER)
DESCRIPTION :
INVALID PROPERTY ,
FOR BEAM ELEMENT
CONCERNING 60 ELEMENT(S)
INVALID PROPERTY ID=0 FOR BEAM ELEMENT ID=1yours sincerely,
kartik kanugo
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Hi,
No property/material is assigned to the beam elements. Please assign the same and run the analysis.
Yes, 3 nodes are required for defining this spring.
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Altair Forum User said:
Hi,
No property/material is assigned to the beam elements. Please assign the same and run the analysis.
Yes, 3 nodes are required for defining this spring.
Hi,
Please check the full h3d file the rope is doing something weird i donot understand. Please see in contour plots of displacement. I have given the stiffness at random for the spring . Is it because of the random stiffness or any other problem.
thanking you,
yours sincerely,
kartik kanugo
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Hi,
This seems like an issue with the spring created. Please recreate and try running.
<?xml version="1.0" encoding="UTF-8"?>
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Altair Forum User said:
Hi,
This seems like an issue with the spring created. Please recreate and try running.
<?xml version="1.0" encoding="UTF-8"?>
It isn't working.... Now again it is detaching as before.
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Hi,
This is happening because of the connectivity issue between the beam and spring element.
Using replace (F3) option you can connect those two nodes. Ensure proper connectivity between the elements and try running.
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Altair Forum User said:
Hi,
This is happening because of the connectivity issue between the beam and spring element.
Using replace (F3) option you can connect those two nodes. Ensure proper connectivity between the elements and try running.
Hi
I modified the whole thing again
this time i connected it with beam element nodes only..
it is acting weirdly. Is it because of the boundary conditions that i have specified for the pulley?
Kindly look at the h3d file.
yours sincerely,
kartik kanugo
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Could you help me in the above problem I am unable to solve it?
yours sincerely,
kartik kanugo
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Hi Kartik,
Please try with the file attached,
For the spring the 3rd node is a way to define the node coordinate system so it is not showing in HyperView. But the simulation seems to be okay.
As a workaround, you could create a /PROP/SPRING with very low stiffness between the nodes that have the missing part of the pulley spring.
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Altair Forum User said:
Hi Kartik,
Please try with the file attached,
For the spring the 3rd node is a way to define the node coordinate system so it is not showing in HyperView. But the simulation seems to be okay.
As a workaround, you could create a /PROP/SPRING with very low stiffness between the nodes that have the missing part of the pulley spring.
Hi George P Johnson,
I ran your model file again it is not correct in the h3d file. Shouldn't the rope just stretch But that doesn't seem to be happening.
I didn't change anything. I only changed the control cards.
(your h3d file uploaded is correct)
yours sincerely,
kartik kanugo
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Hi,
Model is becoming unstable when initial velocity is applied. I don't think this will perfectly work for initial velocity loading condition because this loading condition we typically use for drop, impact, crash cases. For this model an imposed displacement loading condition is required. I tried with the same and it works good.
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Altair Forum User said:
Hi,
Model is becoming unstable when initial velocity is applied. I don't think this will perfectly work for initial velocity loading condition because this loading condition we typically use for drop, impact, crash cases. For this model an imposed displacement loading condition is required. I tried with the same and it works good.
Hi
I did the whole thing again and i think i am doing it wrong.
Could you tell me how to create a pulley element of 3 nodes.
My procedure i am stating below
1) I first create the rope element using line mesh upto the required distance.
2) From there I then create pulley component.
3) I then create the intersecting node of both the ropes. Using node create option in geometry.
4) I go to 1D - then to springs --- then to spring3
5) Then I select in direction option vector N1 , N2, N3 are seen.
6) For N1 i select the left end node of the rope, N2 i select the intersection node, N3 i select the bottom rope node
7) next i mesh by selecting nodes on the left rope and intersection then intersection node and bottom node.
Is this correct because i am getting another h3d file for this procedure so i think i am doing it wrong.
yours sincerely,
kartik kanugo
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Hi Kartik,
I think somewhere you are making a mistake while selecting the nodes for defining the spring.
Please see the attached video showing the spring definition (recorded using a screen capture tool, .swf format which plays in GOM player).
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