In reply to ES 246 project: Plane Strain Extrusion - Slip-line Field Solution vs. FEM Solution
In reply to with Ms. Lu's permission...
i will check it out
In reply to Thanx for your answer, one more question
Can I propse Mr. Hosford's book to draw a simple slf under compression test ? If your question is just draw a simple net, it will helpfull I think.
In reply to ES 246 project: Plane Strain Extrusion - Slip-line Field Solution vs. FEM Solution
Actually slip line field is given by theoretical analysis. It is just an assistant to determine the stress field eventually. If you can figure out the stress field directly from FEM why do you insist to get the slip line field?
In reply to ES 246 project: Plane Strain Extrusion - Slip-line Field Solution vs. FEM Solution
Thank you for your answer for my earlier question.
How can i get the slip-line field from the stress filed solution?
In reply to non-perfect plasticity
Because I also used rigid plasticity in my ABAQUS model I can not tell how accurate perfect plasticity can be used to simulate real metal forming process.
One assumption of slip-line field theory is the perfect plasticity.
In reply to ES 246 project: Plane Strain Extrusion - Slip-line Field Solution vs. FEM Solution
How accurate is the perfect plasticity for metal forming?
How is the slip-line defined for a non-perfect plasticity?
In reply to ES 246 project: Plane Strain Extrusion - Slip-line Field Solution vs. FEM Solution
Hi George,
The slip line is given by theoretical analysis here and I don't think ABAQUS can explicitly draw the slip lines for you. But with the given stress field maybe you'll be able to figure out the slip line field manually.
In reply to ES 246 project: Plane Strain Extrusion - Slip-line Field Solution vs. FEM Solution
Can abaqus give out the slip lines?
In reply to ES 246 project: Plane Strain Extrusion - Slip-line Field Solution vs. FEM Solution
It's very interesting to compare the analytical results from slip-line field theory to the numerical solutions of FEM software. A problem you may encounter in this project is the model's material property. The slip-line field theory assumes a plastic-rigid material, which has an infinite Young's modulus below the yield point and no hardening upon yielding. As Prof. Vlassak mentioned in class, the numerical model with plastic-rigid material may lead to divergence. One possible solution to this problem might be to approximate the plastic-rigid condition as high Young's Modulus, reasonable yield stress, and very low hardening. Moreover, large distortions of elements may occur in your numerical model. If so, you may consider the ALE option for adaptive remeshing in ABAQUS.
It might also be interesting to consider unsymmetrical extrusions with ABAQUS. There is a paper by A.P. Green which proposes slip-line fields and extrusion pressures for unsymmetrical extrusion through a sqare die. I don't know how difficult it would be to move the extrusion opening on your ABAQUS model, but it would be neat to see how the results compare to Green's work.
GREEN AP, ON UNSYMMETRICAL EXTRUSION IN PLANE STRAIN, JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS 3 (3): 189-196 1955
Hi,
Thanks alot for your help.
I need to figure out a slip surface. In order to firgure out the plastic flow of a model, with just solving the static problem. The slip field ( or surface in 3d model) would help me figure out the slip filed.
I have another question which is not connected directly. I need to build a 3D surface with directions parallel to this surface. Its equivilant to an isosurface but instead it has the directions or planes parallel to the overall planes at each point. Does abaqus have this functin?
Thanx again for your help