Structural member with truncated conical portion and composite panel including same

A structural steel member and composite panel including the same and having a sheet of industrial steel having formed therein a pattern of dome-like projections, extending from the plane of the sheet, and of which at least the major portion of each projection is substantially circular in plan view and the projections are arranged in a geometric pattern that substantially limits the elongation of the material to the areas defined by the circular configurations, the dome-like projections also having formed in the peak areas thereof small truncated cones having a flattened uppermost planar surface, parallel to the original plane of said sheet, providing superior overall depth and increased resistance to crushing. When employed in the form of a composite panel, a flat load bearing steel sheet extends across and is fixed to the flattened surfaced of the peak areas, such as by welding, and affords advantageous union of the sheets to form such a composite panel, suitable for use, such as in the art of access flooring.