What the calculator is for
Bending moment and elastic section modulus give the maximum nominal stress. This is useful for quickly comparing candidate beam sections.
Engineering fundamentals
Calculate bending stress
Determine nominal bending stress, allowable stress, utilization, and required section modulus.
σᵦSI
02
Results
ƒ(x)
Set the inputs and run the calculation.
Mechanical reference
Bending moment at a section
Bending moment M acts about the centroidal axis. Bending stress is zero at the neutral axis and increases linearly in magnitude to σmax at the extreme fibres. Reversing the moment swaps tension and compression.
What still needs checking
Valid for linear-elastic uniaxial bending. Notches, fatigue, stability, and combined loading require separate checks.