Wall stress problem

I have inserted particles with young's modulus 1e5 into a cylindrical container and obtained the wall stress. Actual young's modulus of the particle is 1.2 e11. Since I was not able to insert particles with this youngs modulus I intensionally reduced young's modulus and hence im getting reduced wall stress. Is there any factor to be multiplied with the obtained stress to get the actual stress? What is the correlation between these two parameters?
Thanking you

Ullas