## General Mechanical

#### Analyse the Influence of Cracks in Buckling Behaviour

• Divya Giri
Subscriber

Hello,

I need to investigate the influence of cracks on the buckling behavior of a bamboo model.

I can't carry out buckling analysis in the presence of a Semi-elliptical crack and an Arbitrary crack because Ansys doesn't support the buckling analysis with a fracture folder in it. While generating manual crack, the model which was generated with different parts was converted into one solid body. I am stuck and couldn't really decide what would be best fit for me to carry out the influence of crack on the buckling behavior of bamboo culm. Or, Is there any other way to do that?

Any help regarding this would be highly appreciated.

Best Regards,

Divya Giri

• peteroznewman
Subscriber

In SpaceClaim, split the bamboo in half, then sketch (or project) the same circle on each half of the two cut faces. Then on the Workbench tab, use the Share button, but click the red X to remove one edge and one face from the shared topology list.

Then in Meshing, turn off Mesh Defeaturing.  When you mesh, you will have a crack in the mesh.  Here are the node numbers on one half.

Here are the node numbers on the other half. Note that there are separate node numbers in the crack face, but the same node number shared at the crack front.

I meshed with Linear Tetrahedrons only to reduce the number of node numbers displayed to show that this method is working. Use Quadratic Tetrahedrons when you mesh to do analysis.

• Divya Giri
Subscriber

Hi,

I tried the method you suggested, could you have a look if I am going in the right direction? Also, my crack is not as visible as yours and I couldn't display the node numbers.

Regards,

Divya

• peteroznewman
Subscriber

Hi Divya,

Once you have split the cylinder into two bodies, hide both bodies.  Make a sketch on the YZ plane and draw a circle. When you return to 3D mode, it will turn into a circular surface.

Show one half of the cylinder and the circular surface.

Use the Project Tool.

Select the edge of the circle.

Select the Face to limit the projection to.

Click the green check mark then hide the surface.

Repeat this on the other half.

Now delete the Surface and go to the  Workbench Share button.

• Divya Giri
Subscriber

Hi Peteroz,

Thank you so much for taking the time to show me all the steps. It worked but I am still not convinced that I did it right. Could you please show me how you split the cylindrical body? That would be great!

Best Regards,

Divya

Here's how I did it.

• peteroznewman
Subscriber

Hi Divya,

On the Design tab, click the Split Body button, click the cylinder then the plane. That is it.

If you would like to schedule a video meeting, I can show you live and answer your questions.

Best regards,

Peter

• Divya Giri
Subscriber

Hi Peter,

That would be great! Will tomorrow work for you?

Best Regards,

Divya

• Peter Newmann
Subscriber

Yes, I have time tomorrow, Friday. I am in the US Eastern time zone. What time zone are you in?

• Divya Giri
Subscriber

Okay, I am in the Central European time zone.

• Peter Newmann
Subscriber

Okay, you are 6 hours ahead of me. I could meet on Friday at 10:30 AM = 4:30 PM for you.

• Divya Giri
Subscriber

Perfect! That works for me too.

• Peter Newmann
Subscriber

Okay Divya, talk to you tomorrow.