High Stress Concentration in Fillet Radius

The axis of the roller is the x-axis and the end of the roller is in the y-z plane, correct? What is it rolling on - a flat surface, another roller, full width, partial width? What causes the flexural and torsional forces? I'm no FEM expert, but it seems to me that if you are trying to find the max. stress in what I think is the fillet, you need a lot more elements in the fillet itself.

I can't tell if the model includes a shoulder. Do you have a drawing of the roller and the loading? A rounded shoulder would definitely need a finer mesh there although I cannot see why your model shows the high stress' there.

Sorry but i don´t not understand way shows the same image three times. Again I put the links.

I think that the mesh is suficiently good to obtain a reasonable result....I will proof refining more the mesh.

The mesh looks okay there. What is the loading that gives this result?

I have found that when doing FEA analysis's, it's extremely important to fully understand your constraints and loads prior to the analysis. One poorly placed load/constraint can give you an answer completely different than the real world stress/strain.

Double check all your loads and constraints, have another engineer take a look at how you have set up your model for analysis. A second set of eyes are absolutely invaluable.

If you are absolutely 100% sure that all your loads and constraints are exactly as they exist in the real world, and your mesh is even in the ballpark, your results should be within reason.

Any time you get results far from what you would logically expect, back way up and look at it with a fresh set of eyes, and examine loads/constraints/geometry carefully.

The software can only provide you with values based on the input values...

Garbage in = Garbage out.

Best Regards,

-R

Sorry Terraman!! We have crossed!Let me check your answer. It seems very interesting.

I will be back for you.

Thanks

Hi Terraman. Thanks you very much for so detailed response.You and RVZ are rigth. The problems was boundary condition. The new results show in below (in scale for major appreciaton). Note that maximum of V Mises stress is approx 190 MPa!!

Thanks and points for your good answers!!!

True scale:

Your welcome. Glad I could help.

I find that it always helps to magnify the deformation representations so that you can clearly visualize the mechanical behaviour of the material. This will help you determine if you've setup up your boundary conditions correctly.

Cheers.

Thanks Terraman!!. Look at this:

Before

After

This is well beyond a "good" answer!

Still only worth one GA!

There should be another option to rate as "really, really, really good answer". Maybe worth a few extra GAs?

You are right K Fry, but my english language is limited....

My first attempt: TerraMan response was outstanding!!!!!

Thank you very much!!

Muchas gracias por sus respuestas!

Sebastián

Dears

Thanks very much to all for responses. Really, I think that should not have problem with this. This is the upper roll that will be use in the pyramidal roll machine. The forces had been determinated from a analysis the a model relatively simple, but acceptable. The force value is 90 ton and is sufficient to cause plastic deformation in the sheet plate work. The torque necessary has been determinate as follows (please, correct me if this wrong):

conditions for not sliding

Fx => Fr

and Fr :U*N so

T=U*N**Radious upper roll=107,6 kN*m

U (contact Steel /Steel is 074) so

Radious upper roll is 165 mm and force is 90 ton.

Boundary conditions;

motor side: cilindrical support, only free tangential movement. The Torque is applied in this side.

no motor side: cylindrical support, all degree of freedom restricted.

The force is applied in a sector about all length

Gravity activate.

These high values of stress are given in a very Smallest portion.In the remainder stresses are low. I still Think that is not real.