Lower limit in LEFM

Hi,

In have modelled a beam with a hole using LEFM and FEM, assuming a crack length, I was able to indicate the failure load of the beam with a hole. Now, I would like to find a diameter of the hole which I can claim that in this diameter, there is no effect of the hole on the total strength of the beam. Would you please give me an idea of what to do? Is there any thing that I can do withmy model to find out about this? Is there a lower band in LEFM to limit its using?

Thank you,