Provision of component structures with line core elements are known but enhancing beyond a certain level of stiffness for impact resistance is difficult in view of manufacturing tolerances and bond region ratios. By providing discontinuous core elements 102, 32, 42 with through bonding creating gaps 39, 49 between them, bond regions 36, 46 are created. In such circumstances enhancement of local impact or load resistance through achieving specific desired support about the bond regions 46 can be achieved whilst remaining flexible (elastic) enough to resist cracking due to high cycle fatigue. In such circumstances within a structure 101, 41 both continuous core elements 40 and discontinuous core elements 42 can be provided and formed by simple plastic deformation in a single process whilst maintaining manufacturing tolerances and acceptability with regard to bond formation.