How Is Theoretical Fracture Strength Calculated for Glass?

[freeduckies]

Hi, I was wondering what the equation is to calculate theoretical fracture strength if you know the elastic modulus and flexural fracture stress?

Homework Statement

The flexural fracture stress for ordinary (i.e., soda-lime) glass is around 30–70 MPa. Based
purely on the elastic modulus, what is the theoretical fracture strengthof this glass? How can
the difference between reality and theory be explained?

Homework Equations

The elastic modulus for glass is 69 GPa.

Thanks

 

[Valkarie]

! The theoretical fracture strength can be calculated using the equation: Fracture Strength = Elastic Modulus x Flexural Fracture Stress Therefore, for ordinary glass, the theoretical fracture strength would be: Fracture Strength = 69 GPa x (30-70 MPa) = 2070-4830 MPa The difference between reality and theory can be explained by the fact that the flexural fracture stress is just an average value and can vary with the type of glass and external conditions such as temperature, humidity, etc. Additionally, the theoretical calculation does not take into account any defects in the material which can reduce the actual strength.