Confussion with setting up loading conditions on cylinder

[roldy]

I have a horizontally supported cylindrical tube that is fixed at both ends. I modeled half of it to run the simulation on in Abaqus. The only load that it has is its weight. What I get confused at with cylindrical geometry is applying the load. How should I apply the gravitational load and at what location?

 

[Chestermiller]

Isn't the gravitational load uniformly distributed over the volume of material comprising the tube?

Chet

 

[roldy]

That is correct. I just wasn't sure how to set up the loading conditions on a cylindrical surface for gravity.

 

[Chestermiller]

That is correct. I just wasn't sure how to set up the loading conditions on a cylindrical surface for gravity.

The cylinder is horizontal and you are using cylindrical coordinates, correct? So the z axis of the cylindrical coordinate system is horizontal. But, gravity is acting downward. Can you represent the direction of gravity in terms of the circumferential coordinate θ and the cylindrical coordinate unit vectors?

Are you using a shell model or a 3D model? Or, are you treating the tube like a beam?

Chet

 

[roldy]

I am not using cylindrical coordinates, I don't want to have to do any coordinate transformations afterwards. I am using a 3D model that I created.

 

[Chestermiller]

I am not using cylindrical coordinates, I don't want to have to do any coordinate transformations afterwards. I am using a 3D model that I created.

The (distributed) gravitational force per unit volume is equal to ρg, where ρ is the density.