Abstract: A selectively reinforced hybrid metal-composite structural element can include a metal element and a composite material. The composite material can be bonded to the metal element by an adhesive layer including a polymer matrix using a radiation curing process, resulting in insubstantial or negligible residual stresses at the bond line between the metal element and the composite element. The structural element also can include a metal closeout cap to provide a barrier from a corrosive atmosphere, and the adhesive layer can encapsulate the composite element to provide a corrosion-resistant barrier between the composite element and the surrounding metal.