Dear Mr. Shrestha,

I´m quite sure that the issue lies with unrealistic stress concentrations in your model. Typ in google "how to deal with stress concentrations in simulations" and you will find some good answers. It is up to you to implement the solution correctly in your simulation.

Maybe you need also to reconsider your boundary conditions.

Sincerely,

Detlef J.

Dear Shrestha,

Like those cases occur when:

1- The model was not created correctly.

2- The support area was not located correctly.

3- The correct element type was not chosen.

4- The load position and/or value was not selected properly.

Please double check these issues.

Good luck...

Hi Milan, I'm not sure if I have an answer on your question. When bending a beam normally you have to grab/attach by using supports. For the calculation of the shear deflection my friend Rien Huurman applied at the location of the inner supports (4PB beam) a (parabolic) internal shear force distribution over the cross section without using the supports. This is possible in ABAQUS. According to the theory the shear force distribution in the midsection should be constant. Based on the St Venant principle we used the calculated distribution at the center of the midspan (which differs from the one at the location of the support) as the new guess for the original shear force distribution. Already after one iteration the distributions were nearly equal to each other.

If you need the supports for a real bending case I have added a FEM model of a real 4PB device. Have a look on the 4PB platform site of Jorge Pais (Minho Univ.)

Best regards

Ad