Bolted joint

[DwayneHicks]

I wolud like to ask if anybody could help me with following problem. I'm doing a model of single bolt connection in ANSYS with one shear plane which consists of two plates and one bolt. The load is applied as a tension pressure on one side of plate and constraints are applied on bolt (all DOF constrained). My task is to calculate the stresses near the bolt hole. I have applied a standard contact between bolt and plate. When the solution converge I can see the results but my question is why there are so small deformations in the area of bolt. I expected big plastic deformation because the load is so big that the solution stops when the ultimate limit state is reached. The only results I can see is that the stresses corresponds to ultimate limit state but the deformation is very small. I don't know why. Maybe the real constants for contact elements are not good. But I set the standard behaviour with standard contact stiffness. I know that the behaviour is prescribed by the material models but when I use standard linear-homogenous behaviour for steel with ex 210e9 and prxy 0.3 the results are the same. Big stress but little deformation. When I make tests in lab, the results are: big stress and also big deformation. I don't know how to adjust the model in ansys to be functional in this. So the question is, where is the problem, in material model or in contact or in accuracy of solution?

 

[JStephen]

There is a FEA engineering forum on here that gets more attention than this one, try it.

I assume you have the plates lapped together, and are pulling sideways, so as to shear the bolt? Or are you loading in the direction of the bolt?

Is the "big deformation" that you see on actual samples yielding around the bolt? Or plate bending out of plane?

 

[Qshake]

Sounds like an elastic analysis to me. Did you check that your displacements/deformations were consistent with the loading? If so and your experimental results indicate large displacements, you'll need to do a non-linear analysis to account for the large displacements.

Regards,
Qshake

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