How to apply a moment on a cylinder?

[majoon]

I wonder how to apply a bending moment in the center of a cylinder.

I guess some form of coupling and connector have to be made, but dont know how to do it?

The moment should be applied in the axissymmetric axis.

Please help!

/Dredra

 

[gurmeet2003]

majoon,

I think you are talking about a torque and not moment. In order to do this you could define a reference point and link the point to the nodes on the circular surface by kinematic coupling. Then the torque could be applied directly to the reference point. It will be transmitted to the required nodes through the coupling.

Gurmeet

 

[majoon]

thanx, yes thats right.. i have tried the way you proposed, but it doesnt behave as i want it to do. That kind of coupling makes the nodes on the circular surface rigid, and this is not how the reality appears.

Only the rotations are wanted to be equal, but there comes up an error when trying to solve the problem with these conditions.

Is it possible to solve the problem with some kind of connector? Wires are needed, how to apply these and how to apply the moment?

 

[corus]

It depends really on how the moment is being applied to the cylinder. If it's being applied via another structure then the assumption that it is rigid and the cylinder remains round may be valid.

corus

 

[majoon]

sending a picture of how the structure looks like, and how the forces should be put...

this kind of loading leads to that the top of the cylinder deforms...but with the mentioned way of connekting the loadingpoint makes it stiff...

 

[majoon]

here it should be...

 

[gurmeet2003]

majoon,

Have you tried a distributed coupling?

Gurmeet

 

[corus]

The top of the cylinder looks too close to the structure underneath and the way you apply the moment will affect the stresses there, and in a region you're probably interested in. I'd seriously look at how the moment is applied in real life, ie. via another connecting structure.

corus

 

[xerf]

I think you can distribute the moment on the edge of the cylinder by using "Shell Edge Load" -> Traction : Shear.
The magnitute of the shear traction should be set such that by integration to get the applied moment.

 

[rejoicepaul]

I met the same question with majoon,could you tell me whether you have solved this problem or not?
thanks!