Engr Help

Shear Stress in Beams (continued) Click here for discussion of Shear Flow in Beams

Key Concepts: Transverse loads, such as P, acting on beams result not only in internal shear stress but also an internal bending stress. See the figure below.

In a Nut Shell: Unlike the shear stress, the bending stress is zero at the neutral axis and

increases linearly from the neutral axis to the outer fibers of the beam.

The bending stress, σ , at an arbitrary location, y, from the neutral axis is the same as
before:

σ = My/I

where      M is the bending moment at the section
                  y is the distance from the neutral axis to the fiber where the bending stress
                      is being calculated
                  I is the moment of inertia of the entire cross-section about its neutral axis

Click here for an example.

Return to Notes on Solid Mechanics