ANSYS: Load a tangential displacement in cylindrical coordinates system

[Batosai]

Well, let's see.

I defined a cylindrical local coordite system. Then I rotated the nodes to that coordinate system.

Now what I want is to define a displacement on the tangential direction without fixing the radius.

The problem is that ansys says that a cylindrical coordinate system is that way: R,θ,Z

But the reality is that θ is not in degrees nor radians, it's in mm. But... wich longitude is it taking? I'm pretty sure that's not the arc longitude, but then what? Anyone knows?

PS: I've already read all the help topics in ANSYS but they don't say nothing about it.

PSS: In case it's a longitude, how would I know the longitude if I don't know the strains and how much the piece is going to elongate? Why Ansys developers hasn't used radians for θ, what the hell were they thinking about????

Thank you very much for your attention.

 

[rb1957]

sounds very odd ... would've thought theta was in radians.

since you can't define the tangential direction in cyclindrial co-ords (easily), i'd create a second co-ord system origin at the node in question, one axis tangential ...

 

[Batosai]

So you can define a co-ords system that keeps moving with the node? Can you teach me how?

Ty

 

[rb1957]

not really ... your co-ord system would be set up according to the original geometry. to give the tangential direction, i'd create a rectangular co-ord system at eh node in question.

 

[rb1957]

would it help to convert your model to a rectangular co-ord system ? should be "just a button push" ...

 

[Batosai]

Another problem related to the previous one.

Using ANSYS cylindrical coordinate system R,θ,Z doesn't allow you to introduce a Load of θ for more than 90º

Anyone have done it? I'm working in a nonlinear Large displacement analisys.