24.1 : 梁の主応力

A prismatic beam exposed to arbitrary transverse loadings, results in shear and bending moments.

The stress on a surface element of the beam is normal stress, while on a neutral surface, it is shearing stress.

The maximum normal stress within the cross-section may surpass normal stress at the surface of the beam.

The principal stress distribution in a narrow rectangular cantilever beam under a concentrated load is studied to analyze the maximum normal stress.

The computational results indicate that the maximum normal stress doesn't exceed the normal stress in either of the two beam sections.

If it does, it's typically in areas near the load where normal stress is less than the shearing stress.

The maximum normal stress equation computed for rectangular sections can be applied to many nonrectangular cross-section beams.

However, when large shearing stresses coexist with substantial normal stresses near the beam surface, the maximum normal stress might exceed the normal stress.