Learning Forum

[Dustin Sondenaa]

I have a relativly large assembly that I'm running through Modal, Shock, and Vibration. Due to the size the fasteners were replaced with beam elements but I'm slightly worried that I'm not properly capturing the joint stiffness since I have metal to metal contact with preload.

Without doing the full joint stiffness is there a good way to simulate the surface to surface interaction by adding in bolt pre-tension or frictionless contact or something? 

I have searched the best I can but it seems like most examples have a gasket that allows the 2 flanges to move independantly instead of sharing the load.

[Ashish Khemka]

Hi Dustin,

One suggestion is what if you increase the beam radius - this will result in stiffer beam. Another approach may be to run a simple model and see how much difference in result you see when modeling beam and when modeling actual parts.

Regards,

Ashish Khemka

[Dustin Sondenaa]

Thank you for the response. We could increase the beam radius but the queston would become how large is unrealistic.

If we were to model the parts as a simpler model wouldn't we still need to provide ansys with information on the face to face contact of the joint to prevent the two surfaces from passing through each other? I was thinking either a frictonless contact or "no seperation" constraint would be appropriate in this case to account for the flage to flanger interaciton rather than just soley relying on the fastener beam to be the stiffness. Am I incorrect in my thinking?

Obviously an image would help and I will try to generate something

[Ashish Khemka]

Hi Dustin,

 

You can use a bonded contact. Please see the following external link which might be useful:

ANSYS Mechanical: Strategies for modelling bolted connections | EDRMedeso

Regards,

Ashish Khemka