Method for producing cold roll-formed structures

摘要

A cold-forming method is disclosed for thinning localized, longitudinally extending portions of sheet metal by lateral shear deformation without any substantial longitudinal deformation. With such method, it is possible to produce elongated members which are thinned in zones of low stress and are thicker in zones of higher stress so as to provide high metal use efficiency. The method is performed by an apparatus including a rotating mandrel providing opposed conical surfaces and pressure rolls operable to apply forces substantially perpendicular to the axis of rotation of the mandrel to cause a portion of the sheet metal to yield in shear to reduce the thickness of longitudinally extending portions of the sheet metal. The forces are applied in a plane normal to the length of the strip in order to avoid longitudinal elongation.