Hello everybody,

UPDATE : Question can be deemed as closed.. :)

I have a very simple doubt in 3D model simplification. I believe plane stress and plane strain conditions are the two extreme states to simplify a 3D model to 2D case.

• I took a simple example of a square plate. I fixed the bottom edge and applied a force (say 1000 N) on the top edge. Analysing it as simple 2D cases of plane stress and plane strain, I have some results for von Mises stress in the plate.
• Now extending the same to 3D, I applied same force (1000 N) on the top face and fixed the bottom face. I expected a result between the two extremes of negligible thickness (P.stress) and very high thickness (P.strain), but my result of 3D was an order of magnitude less.

What I think is, I should scale the applied force (in 2D) proportional to the area (Area*(Force/unit area)) in which it is being applied, to get result between the two extremes. Is that the right way?

Please correct me if I am wrong.

Thanks for your time.

Regards,

Shree

Hi,

I am trying to run a uniaxial compression test using Abaqus Explicit, the simulation is using a cuboid specimen ( 2mm x 2mm x 4mm ) and the deformation is homogeneous, as I am using dynamic solver to analyze a static problem, the stable time increment is very very small, about 1 x 10^(-8). It would take at least 2-3 days just to finish the computation of an simple uniaxial compression test (with 25 seconds time step). This is really too long for me as I need to run at least 10 different uniaxial compression simulation with different strain rate. I am thinking since my specimen is cuboid and it's deformation is homogeneous, can I use 2D simulation like plane stress or plane strain simulation to proceed the analysis instead of 3D simulation, is it theoretical reasonable? If not can anyone suggest me on how to speed up the simulation? Like choosing certain mesh option and so on.

PS: I have to use Abaqus Explicit because the next step is the implementation of a VUMAT

Thanks and regards

Hello

I am working on a thesis project dealing with flow stress in cold rolling, a plane strain operation. To determine the flow stress, tensile tests were carried out. I am aware, that the engineering strain/stress hast to be transfered to the true strain/stress and then the true strain/stress from the tensile test has to be mulitplied with the Von Mises yield criterion to yield the correspondent compressive flow stress in the rolling situation.

But i dont know which strain from the rolling reduction I have to input into the flow curve which is determined by the tensile test.

For example: if, during one pass, there is a reduction from 3.5mm to 3mm in rolling, resulting in a draft of 0.5mm and a strain of (3.5-3)/3.5=0.143, can i input this strain directly into the true stress-true strain curve to get the true flow stress or do i have to modify the strain first, to "translate" it from the rolling reduction (compressive, plane strain) to the situation in the tensile test (uniaxial stress)?

I would be very thankful if anybody can help me with this problem.