Pre-stress cables

[aramalhinho]

Hi,

I'm getting some intabilities in some nodes and I can't understand why.

And my model it's not converging also.

I tried with a simpler model with only one cable structure and worked fine, but when I introduce others (see attachement) it doesn't work.

Can anyone check the model for any mistake I've done.

Thanks.

Regards,

Andre

[Rafal.Gaweda]

Apply RX support in nodes 105to114By3 107to116By3
Cables do not have any rotational dof so bars 55to67By4 58to70By4 can rotate aound their local X

[aramalhinho]

Hi Rafal,

Thank you for the reply.

That solved the instability issue but now I'm getting a warning regarding the 'matrix' and that 'the critical load may have been exceeded', and it's not converging again.

Any thoughts? 

Regards,

André

[Rafal.Gaweda]

Far too low critical coefficient if you run buckling for self weight only.

[aramalhinho]

Hi Rafal,

Buckling on the cables!? Strange...that means that I need to increase the section of the cables? or add more cables?

Is there any tutorial or example how to do a cable analysis? Or the way I've done is correct? problem being the buckling.

Thanks.

André

[Rafal.Gaweda · Accepted solution]

Buckling on the cables!? 

No, buckling of WHOLE structure

Is there any tutorial or example how to do a cable analysis? Or the way I've done is correct? problem being the buckling.

Search forum, but more less you made model OK, but structure is unstable (I mean it buckles)