Stress-Strain Relationship

Hooke's Law states that the stress is related to the strain according to:

(1)     

where:

is the stress,

is the strain, and

E is Young's Modulus.

Also, stress is related to the moment by:

(2)     

where:

h is the thickness of the beam (and h/2 is the distance from the neutral axis to the top of the beam) and

I is the moment of inertia.

Combining Equation 1 and Equation 2 yields:

(3)     .