Shear Center is a point through which if the external load passes, then there will not be any twisting of the section.
The section will only be subjected to bending. It won’t be subjected to Torsion. (Torsion due to Load being applied at a distance eccentric to the shear center)
In an Unsymmetrical section, if the external applied forces act at the centroid or any other point(but not Shear Center) of the section, then in addition to bending, twisting is also produced. To avoid twisting, and causing only bending, it is necessary for the force to act through a particular point(which may not coincide with the centroid). The position of this point is the function only of the beam Geometry, and this point is termed as Shear Center.
Some Properties of Shear Center:
· The transverse force applied at shear center does not lead to the torsion of thin-walled beam.
· The shear center is a center of rotation for a section of thin-walled beam subjected to pure torsion.
· The shear center is a position of shear flows resultant force, if the thin-walled beam is subjected to pure shear