The accommodation of movements and the method of articulation chosen ... should be assessed .. . using engineering principles based on elastic theory.. .
Inherent restraints must be assessed and their effects minimized unless they induce a beneficial preload or are required to provide stability, as in the case of column bracing or plate stiffeners. Neglect of these strains may lead to expensive maintenance problems or failure by fatigue of steel or brittle fracture of concrete, due to biaxial or triaxial tension. Modern structural forms utilizing welded steel or prestressed concrete are not only frequently more complex and torsionally stiff, but are also more flexible and ductile than their older riveted mild steel or reinforced concrete counterparts. This flexibility may be internal, external or variable with the type and direction of movement.