Very different result between 2D and axisymetric

[Luke720]

Hi,

I'm working on an impact problem with a sphere hitting a deformable substrate. I did it first with and axisymetric model and I got results that look good/expected. No I want to add complexity that rules out an axisymetric approach, so I tried to recreate what I have so far in 2D.

The trouble is, the deformation that I'm getting in 2D is much different than in axisymetric and I don't know why. The spherical particle is deforming less and the substrate is deforming more. I used the same temperatures, velocity, and material definitions.

Anybody run into this before? Or does a possible source of this error spring to mind? I'd really appreciate any advice.

Thanks!

 

[corus]

How do you model a sphere in 2D? Are you sure you're not in fact modelling a solid cylinder which would be stiffer and such give lower deformation in the 'sphere' and greater deformation in the substrata?

 

[Luke720]

I bet that's it! Now I feel dumb but that would explain things. Thank you.

Is there a way to make it assume that a circle in 2D is a sphere and not a cylinder? I guess it's probably just in the part creation options, I should be able to figure it out but I wont have access to ABAQUS until Monday.

Thanks!

 

[corus]

An axisymmetric model is 2D, with dimensions in R and Z. Your sphere is represented in 2D by an axisymmetric model of a 180 degree segment of the sphere in the positive Radial direction. Of course you wouldn't be able to move the sphere in impact so your only choice is a 3D model.