The maximum bending stress () is the highest stress experienced by a beam’s cross-section when subjected to bending moments. It usually occurs at the top or bottom fibers of the beam depending on the bending direction.
The formula for maximum bending stress in a beam under a bending moment () can be given as:
where:
- = Maximum bending stress (in pascals, Pa)
- = Maximum bending moment at the section (in newton-meters, N·m)
- = Distance from the neutral axis to the outermost fiber of the beam (in meters, m)
- = Moment of inertia of the beam’s cross-sectional area (in meters to the fourth power, m⁴)