| 摘要 |
Precision-folded, high strength, fatigue-resistant structures and a sheet (41 ) therefore are disclosed. To form the structures, methods for precision bending of a sheet of material along a bend line (45) and a sheet of material formed with bending strap-defining structures, such as slits (43) or grooves, are disclosed. Methods include steps of designing and then separately forming longitudinally extending slits (43) or grooves through the sheet of material in axially spaced relation to produce precise bending of the sheet (41) when bent along the bend line (45). The bending straps (47) have a configuration and orientation which increases their strength and fatigue resistance, and most preferably slits (43) or arcs are used which causes edges to be engaged and supported on faces of the sheet material on opposite sides of the slits or arcs. The edge-to-face contact produces bending along a virtual fulcrum position in superimposed relation to the bend line Several slit (43) embodiments suitable for producing edge-to-face engagement support and precise bending are disclosed. With these teachings, forming numerous three-dimensional load-bearing structures from a two dimensional sheet (41) are enabled. Examples of straight and curved beams, chassis, and exoskeletons are disclosed. |
