Abstract: The invention concerns a method for assembling at least two simple sheet metal elements (1, 2, 3, 11, 12, 21, 21?, 22, 22?) for producing a structural part with open section, preferably U-shaped, or closed section, at least one of the metal elements having a high or very high yield strength and low deformability. The invention is characterized in that the metal elements are formed by at least a folding process; the metal elements are arranged relative to each other along a junction section; the metal elements are assembled by a crimped lap-joint (4) along the junction section of said elements.

Abstract: The invention concerns a beam structure comprising at least a wing (1, 1′) made of at least a first metal and at least a core (2, 2′) made of at least a second metal, said core being assembled substantially perpendicular to said wing and said core being a sheet material or sheet metal. The invention is characterised in that the first metal has a high or very high yield strength, and associated with a yield strength/tensile strength ratio close to 1, the second metal has a yield strength substantially lower than that of the first metal; the second metal has a yield strength/tensile strength ratio substantially less than 0.9 and less than the value of said ratio exhibited by the first metal.