Bending moments cause internal stresses that vary linearly from the neutral axis.

ϵ=δLepsilon equals the fraction with numerator delta and denominator cap L end-fraction For materials in the elastic region.

The most basic concepts involve forces applied along the longitudinal axis of a member. The internal force per unit area.

σ=−MyIsigma equals negative the fraction with numerator cap M y and denominator cap I end-fraction (Where is the distance from the neutral axis and is the moment of inertia). Occurs at the furthest fiber (

Torsion refers to the twisting of a structural member when loaded by couples (torques). Maximum at the outer surface (

ϕ=TLGJphi equals the fraction with numerator cap T cap L and denominator cap G cap J end-fraction (Note: is the polar moment of inertia; for solid shafts). 3. Pure Bending

τ=TcJtau equals the fraction with numerator cap T c and denominator cap J end-fraction Measured in radians.