Torsional Gap on a simplified model
Torsional Gap on a simplified model
(OP)
Helo,
I am brand new to Nastran and Patran so with just a week of experience.
I have been trying to model a loose contact so that once the beam deflects some degrees, then a moment will be created at a pivot point. The magnitude of the moment is dependent on the degrees of defection much like a torsional spring.
I started modeling the whole scenario without the torsional gap and it works out fine on SOL 101; now that I am trying to add the gap I am having trouble on actually finding a way to implement it. As far as I know, there is no specific function/card on torsional gaps, and CGAP only seems to work for linear cases. I am completely stuck and all the research I've done on this has lead me now where.
Possibly using linear gaps?? but how?
below is an a diagram to better help understand what I am talking about.
I am brand new to Nastran and Patran so with just a week of experience.
I have been trying to model a loose contact so that once the beam deflects some degrees, then a moment will be created at a pivot point. The magnitude of the moment is dependent on the degrees of defection much like a torsional spring.
I started modeling the whole scenario without the torsional gap and it works out fine on SOL 101; now that I am trying to add the gap I am having trouble on actually finding a way to implement it. As far as I know, there is no specific function/card on torsional gaps, and CGAP only seems to work for linear cases. I am completely stuck and all the research I've done on this has lead me now where.
Possibly using linear gaps?? but how?
below is an a diagram to better help understand what I am talking about.





RE: Torsional Gap on a simplified model
www.stressebook.com
Stressing Stresslessly!
RE: Torsional Gap on a simplified model
RE: Torsional Gap on a simplified model
www.stressebook.com
Stressing Stresslessly!
RE: Torsional Gap on a simplified model
RE: Torsional Gap on a simplified model
In the model, use a custom cylindrical coordinate system, then update the nodal (both nodes of the CBUSH) definition and output CSYS to this cylindrical CSYS.
In the PBUSH definition dialog box, click the Nonlinear/Freq. Response spring and use the function you defined at the bottom for the DOF 2 displacement (theta).
Use SOL 106 and try a simple test model first. Lastly, if the Fairy Godmother waves her majic wand when you solve it as well, hopefully things will fall right into place.
www.stressebook.com
Stressing Stresslessly!