Learning Forum

[Hanh]

Hello everyone,

I want to verify the values of stress and deformation of rotating wheel. I implemented the model in Transient Structural Module like attached figure. The boundary condition is just only Rotational Velocity and its value is 1 rad/s. But I am not sure the way I implemented in Ansys Workbench is right.

Can you help me?

Massive thanks.

[peteroznewman]

Hello Hanh,

If you want to know the stress in a flat disk due to rotational velocity, you use a Static Structural model. I know, it's counter intuitive.

Your geometry is lacking a feature to anchor it to ground such as a center hole or center shaft. That is what you would use as a fixed support instead of the revolute joint.

The problem with the revolute joint is that it is holding onto the very material you want to see expand out due to rotational velocity.

I will say that your rotational velocity is very small so the stress will be insignificant.

[Hanh]

Thanks Peter,

Because of a new Ansys Workbench user. I first try to verify the result of simple models in Transient Structure module, then I will perform a complex model based on the previous results. So, I want to solve some models to solidify my knowledge like your model that I found in this forum.

Can you help me?

Thank you very much.

 

[peteroznewman]

If you want to know the stress in a body due to rotational velocity, you use a Static Structural model with a Rotational Velocity Load. In the image above, you could use a Fixed Support on the face of the hole.  What version of ANSYS are you using?

There is a "Guide to Rotodynamic Analysis" in the Help system.

[Hanh]

Thanks Peter,

I am using Ansys Workbench 19.2.

You mean that I should to use inertial Rotational Velocity Load and Fix support on the face of the hole instead of using Joint Connection and Joint Load. So, How can I see animation of the body during its moving?

Hanh.

[peteroznewman]

Yes, an Inertial Load of Rotational Velocity with a Fixed Support.  That calculates the stress and deformation in the part due to the rotational velocity.

You don't see any animation of the body moving. Why do you need that?

 

[Hanh]

Thanks Peter,

I want to determine time-varying stresses, deformations of the part and strategy of the part follow time-dependent loads. This is the reason I’d like to simulate in Transient Structure module and using joint.

Dear sir, Can I use joint connections in Static Structural module ?

Hanh.

[peteroznewman]

Of course for time-varying stresses, you need Transient Structural.  It is always a good practice to start with a simpler model and progress to more complicated models. For example, before you run a Transient Structural model, you should run a Modal analysis to see the frequencies that are present in the structure.

Yes, you can use a Revolute Joint in Static Structural. You just add a Joint Load, where you set the Rotation Angle to 0.  Then duplicate that model and change the Joint Load to Velocity.  It would be best to use an equation or tabular data to ramp the velocity up from 0 to the final velocity if you are looking at start-up transient effects.

[Hanh]

Thank you very much.

sincerely.

Hanh

[Hanh]

Dear Mr. Peter,

I simulated a single pendulum in both of Static Structural and Transient Structural modules to compare the results. But I received the different between two results.

Can you consider my results and guide me how to do that?

Thank you.

 

[Christian Schreiber]

Hello everyone,

how do I set up the boundary condition to see the deformation at the diameter of the hole in the Example of hanh (February 18, 2020 at 2:04 pm)? If I use a fixed support on the face of the hole in combination with rotational velocity load, the deformation of the hole is blocked and equals zero. Is there any good solution for this?

Thank You very much,

Christian