What is the method for calculating the breaking stress of brittle steel?

[german1234]

Hi

If I was to heat a steel rod that is brittle...then clamp it at both ends and allow it to cool to a certain lower temperature at which it breaks, how would I go about calculating the breaking stress of the steel. [ I know value of E and alpha]

Thanks for any help you supply.

 

[Studiot]

What are your thoughts first?

Why would it break rather than simply stretch according to Hookes law?

I mean what is your proposed failure mechanism?