Learning Forum

[cetingrdk]

Sir I am having a "clamped-hinged beam" and I have to analyze frequency parameter of this beam.

So my question is that how to apply this  supports on the Ansys Workbench.I searched all about this topic but couldnt find the answer yet.

Thank you for your answers already.

[peteroznewman]

Here is the image you attached.

You say you have to analyze frequency parameters, but that is not mentioned in the image.

ANSYS Mechanical can apply fixed and pinned supports to the left end of the beam.

The Roller support is created by having a Displacement boundary condtion that has a single 0 translation (Y axis for example) and the other two are Free.

You should use surface geometry to build this model and select the edge of the surface to apply these supports.

[cetingrdk]

I want to make a beam like one end is fixed and other is hinged or roller supported sir.

I fixed left end of the beam  to make a clamped support.As shown in the figure.

 

And I used 'remote displacement' for pinned to the right end of the beam.I applied Y axis to the 0mm displacement.

 

 

I just couldn't find my mistake.Where am I making a mistake sir?

[peteroznewman]

 On the existing Remote Displacement, set X, Y and RotZ to 0 and leave all others free. That is more like a roller support that is free in the Z direction.

You are to compare two boundary conditions, so you need two Modal analysis systems. In Workbench, you can Duplicate the first system to get a second one.

In the second Modal analysis, delete the Fixed Support and create a Remote Displacement on that face. Set X, Y, Z, and RotZ to 0 and leave all others free. That is a pinned connection.

Each system will have different Mode 1 frequencies.

[cetingrdk]

Sir I'm sorry for disturbing you again

But I have to analyze frequency of the beam which has C-H boundary condition.Its clamped-hinged supported beam.

When I analyze this beam on Ansys, the results didn't match analytical solution.There are 2-3 hertz difference between my analytical solution and ansys solution.

I set X,Y and RotZ to 0 and left all other free on the right end of the beam to make a hinged support and set every value to 0 on the left end of the beam to make a clamped support.

In addition I set X,Y,Z and RotZ to 0 and left all other free on the right end of the beam to make a hinged support and set every value to 0 on the left end of the beam to make a clamped support.

I tried 2 ways but the results didnt match at all.And I'm sure that my analytical solution correct because I checked that solution at least over 10 times.

[peteroznewman]

Is it 2-3 Hz too high or too low?  Does the hinged match more closely than the clamped?

Please provide a table with the two conditions in rows and two columns with the analytical result and the ANSYS result.

When you create a Remote Displacement, the default is a Behavior = Deformable.

Try changing the Behavior to Rigid.

[cetingrdk]

Sir this one is the frequency of the hinged-hinged supported beam.As you can see the results are very closely to each other.This is correct solution for first part of my graduation project.

 

 

 

And this table is my second part of my project which one clamped-hinged supported beam.As shown in the table the first modes have very close values.But I have issue about other modes.4 or 5 hertz really big difference for me.I know its too difficult to help from on the internet.Even though you dont have anymore advice sir, nevertheless I'm really glad you tried to help.Thank you again. 

  

[Dyah Wijayanti]

Hello, can I ask for the manual equation to get the natural frequency of the clamped-hinged beam?

[peteroznewman]

Did you do a Mesh Refinement Study to see if the element size affects the Frequencies?

Convert your solid body to a beam element in SpaceClaim. That is very simple to do, see the start of this video.

Then you can use Displacement Boundary Conditions and Fixed Rotation on the vertex of the line body at each end. I expect you will get results closer to analytical.