Be careful with generalised statements about the bending stresses being 'maxima at centre span' and shear force being 'minima at the supports'. That's only true for beams or joists simply supported at the ends. It certainly is not the case for cantilevers, or overhung joists, or where intermediate props (like a studwall) are introduced or where point loads are applied, or where the ends are fixed, or where the beam is considered continuous, [ie. with multiple supports].
Alan
