How to model closed crack in beam in ANSYS

[georg2976]

Dear people,

I want to put the crack but closed at the midspan of the beam with depth half of height and with wight all of beam. Can somebody save a file or explain how to do that.

Regards,

 

[uwcomposites]

Have you looked into VCCT elements? I can help you with that.
What do you mean with placing the crack at the midspan of the beam? Can you be more descriptive of your specific problem?

 

[georg2976]

I don't know what is VCCT elements. Can you make me a model for example beam L=1m, h=0.05m b=0.05m. Crack depth hc=0.025m, crack width bc=0.05m, crack length lc=0.01m. And show me how to do that?

 

[uwcomposites]

VCCT: Virtual Crack Closure Technique.
Are you after the stress intensity factors? Are you trying to predict where the crack will go (KI, KII and KIII)?
If so, I have a set of instructions on how to do that in ANSYS than I can share with you.
Let me understand if this is what you are trying to do.

 

[georg2976]

NO, my main problem is to obtain natural frequencies for cracked beam. So I need a cracked model and then natural frequencies. If you have some instructions or make a model with crack to show. The problem is easy but I am new in ansys so I don't know how to do that.

 

[uwcomposites]

I see. As a first approximation I would suggest to simulate the crack as a segment of no attachment between the upper and lower surface. What I mean, be creative in the modeling so that there is an segment and is free to open
I hope this helps,
-Francesco