problem in symmetric shaft with bending moment

  • Last Post 28 June 2019
claudiocozza posted this 18 June 2019

hi everyone, 

i'm a new user of ansys academic 19 and i have some issues with a stepped shaft for evaluating kt (stress concentration)

i've divided the shaft and i've only 1/4 of the shaft, then i put the symmetry and antisymmetry constrains with displacement (1 and 2) and i put the bending moment on a side of the shaft and a fixed support at the another side

when i run the code the results are very strange for the phisics of the problem, so i'm obviously doing some mistakes that i don't see

can you help me?


ps. there are some attached images. don't look at the mesh, i have to refine it


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claudiocozza posted this 19 June 2019

PS. I've found where the problem is located: 

1) when i run the code with 1/2 shaft with only the symmetric constrain, results are good

2) instead, when i run 1/2 shaft with only the anti-symmetric constrain, results are bad

so, what am i doing wrong? i've already tried to remove the displacement on the antisymmetric constrain and selecting a frictionless support, i've finished my ideas

the symmetries are shown below with the displacement constrain

claudiocozza posted this 23 June 2019


peteroznewman posted this 23 June 2019

I don't use anti-symmetry. When I tried it, I wasn't satisfied with the results.

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  • claudiocozza
claudiocozza posted this 28 June 2019

I’ve just talked with my FEM professor, we didn’t find a solution for this problem primary because there are unsatisfactory solutions for the Moment reaction in the fixed support. I will apply only the symmetry.