I have written my own finite element code for a linear elastic (plane stress) problem consisting of a plate with a circular hole in the middle, fixed on one side, having a tensile force acting on the other side.

I have obtained displacements and calculated the stresses and strains at the nodes. I want to calculate the stress concentration factor numerically and compare it with theoretical values for the same case.

I understand that the stress concentration factor $K_{t}$ is given by

$$ K_t = \frac{\sigma_{max}}{\sigma_{nom}} $$

$\sigma_{max}$ is very easy to find but I have trouble understanding how to calculate $\sigma_{nom}$ for my problem.

Any help would be appreciated!


1 Answer 1


$\sigma_{\text{nom}}$ is the stress in the component without a hole.

You should be able to calculate that by hand, without needing to create another FE model ;)

  • $\begingroup$ Thanks for the answer! This may seem like a silly follow up question but my plate also has some fillets with stresses concentrated near them in addition to the central hole. Do I have to consider a plate without holes and fillets to calculate the nominal stress? $\endgroup$
    – Anirudh N
    Jun 22, 2019 at 9:39
  • $\begingroup$ Link to diagram: imgur.com/gxiY5VG $\endgroup$
    – Anirudh N
    Jun 22, 2019 at 9:47
  • $\begingroup$ Since you have large holes and large fillets compared with the size of the plate, all the features will interact with each other and it's not very obvious what a single "stress concentration factor" would mean anyway. If you make the plate longer (theoretically, infinitely long) with no fillets and only one hole, this will give you theoretical solutions: amesweb.info/StressConcentrationFactor/…. For a very small hole, the stress concentration factor is exactly 3 For bigger holes, it is less. $\endgroup$
    – alephzero
    Jun 22, 2019 at 18:30

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.