Patent ID: 8678267

Claim:
A method of forming a unitized assembly, comprising the steps of: providing a fiber metal laminate having non-metallic plies bonded to metallic plies and having at least one innermost metallic ply; depositing, by friction stir welding, a first additive layer onto the innermost metallic ply at a thickness less than successively-applied additive layers, the innermost metallic ply having a thickness greater than the thickness of the remaining metallic plies; generating, when depositing the first additive layer, a weld nugget smaller than the weld nugget joining the first additive layer to a successively-applied additive layer such that a lower edge of the weld nugget boundary for the first additive layer is located above a first non-metallic ply; and successively depositing and joining a plurality of the successively-applied additive layers in a stack onto the first additive layer by friction stir welding such that the innermost metallic ply is on a bottom of the stack, the additive layers and the innermost metallic ply comprising a friction stir welded preform, each additive layer being a unitary structure prior to depositing on the stack, the additive layers collectively forming a substructure element, the joining of the additive layers to the innermost metallic ply and to each other being limited to joining by friction stir welding.