Solution:When a structural member is subjected to transverse loading with that the bending of beam occurs in the principal plane of section, then the neutral axis of the section of beam is perpendicular to the plane of bending.
The neutral axis passes through the centroid of section, if the transverse loading is such that the bending of beam occurs in a plane other than the principle plane of section, the beam section is subjected to unsymmetrical bending channel section.
• The direction of neutral axis is not perpendicular toplane of bending. The maximum bending in a beam section subjects to unsymmetrical bending may be determined by following method–
(i) By revolving bending moment into two components
along the principal axes.
(ii) By revolving bending moment into two
components along any two perpendicular axes passing
through the centroid of the section.
(iii) By locating the neutral axis of section.