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kranic24
Posts: 19
Registered: ‎04-05-2012

Cable to Cable Attachment

138 Views, 4 Replies
05-01-2012 08:56 AM

I keep getting errors when trying to model a simple span cable that has nodes along the span for a plate attaching to it. Fixed ends (Node 1 and 5) and only restriction in the Z at Nodes 2 thru 4.  Bars 1 thru 4 is one cable while members 5 thru 8 is a 1/4" steel plate.

 

Can anyone look at my model to help me figure out my problem? I'm thinking its a "release" issue.

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Valued Mentor
tony.ridley
Posts: 652
Registered: ‎09-07-2011

Re: Cable to Cable Attachment

05-01-2012 04:10 PM in reply to: kranic24

Do you mean a true cable or just a "round bar"?

 

I can't see your model (no Robot in this office today) but I'm pretty sure you can't use a true cable for this kind of modelling......

 

Also, I don't think you can model releases in cables. 

 

Tony

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Artur.Kosakowski
Posts: 4,544
Registered: ‎12-17-2010

Re: Cable to Cable Attachment

05-02-2012 12:32 AM in reply to: kranic24

The error is caused by the fact that you applied imposed displacement load in the nodes that do not have this d.o.f restrained. You need to define supports with the imposed direction of displacements blocked. It seems that in fact you applied all values as 0 so perhaps it is some kind of the mistake there. Also the cable has got no torsional stiffness so the parallel bars need some supports as well.

 

In addition I think that you should include self-weigh in the assembly load case and then apply other load in the following load cases.

 

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.



Artur Kosakowski
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Contributor
kranic24
Posts: 19
Registered: ‎04-05-2012

Re: Cable to Cable Attachment

05-02-2012 07:01 AM in reply to: Artur.Kosakowski

Thanks for the response Artur. I'm still not able to get this model to work. I have provided supports (Z direction) for both plate nodes and mid-cable nodes. I also applied the imposed displacement as recommended. Any other thoughts? Is this possibly a timestep issue?  Thanks in advance.

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Product Support
Artur.Kosakowski
Posts: 4,544
Registered: ‎12-17-2010

Re: Cable to Cable Attachment

05-02-2012 07:24 AM in reply to: kranic24

You are not allowed to define supports in the slave node of the rigid link therefore you have to replace them with bars. In addition you need some additional supports to prevent instabilities as well as mark the stiffness matrix update after each iteration.

 

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

 

 



Artur Kosakowski
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