Abstract: An optical system and method of measuring a strain on a surface of a band of a sheet of a material. A single line, or an area having a boundary line, is marked on the band before deformation. The line traverses a width of the band at angle. The band is deformed and an equivalent two-dimensional image of the line after deformation is obtained. The line before deformation is compared with the two-dimensional equivalent image of the line after deformation, and the strain on the surface of the band after deformation is determined.

Abstract: A sheet metal assembly includes first and second metal sheets having flanges extending from the sheets. The flanges overlap and are in engaged parallel facing relation for a width between outer edges and flanges. At least one pair of self-piercing rivets joins the flanges at spaced locations along the width. The rivets each have a head and a shank extending into the flanges from opposite sides. The rivet heads of each pair are located in opposite flanges and are spaced further from the outer edges of their respective flanges (nearer the load-application ends) than are the shank portions of other rivets of the pair.

Abstract: A sheet metal assembly includes first and second metal sheets having flanges extending from the sheets. The flanges overlap and are in engaged parallel facing relation for a width between outer edges and flanges. At least one pair of self-piercing rivets joins the flanges at spaced locations along the width. The rivets each have a head and a shank extending into the flanges from opposite sides. The rivet heads of each pair are located in opposite flanges and are spaced further from the outer edges of their respective flanges (nearer the load-application ends) than are the shank portions of other rivets of the pair.