The use of shear connectors, which are often known as shear studs, is to create a solid, complete connection between two different materials. In bridge deck construction, building construction and similar types of applications, this connection is between concrete and steel.
Through his use of shear studs, the two materials are bound to each other, allowing them to resist twisting, bending, sagging or independent movement between the two. Instead, they obtain a stronger, more rigid and more durable form, resisting shear forces and working as a composite material that is stronger than either one on its own.