FATIGUE-RESISTANCE SHEET SLITTING METHOD AND RESULTING SHEET.

摘要

A sheet of material (111) having a plurality of bend-inducing structures (113)configured and positioned to produce bending along a bend line (115). The bend-inducingstructures (113) have arcuate return portions (122) extending from oppositeends (121) back along the bend-inducing structures (113) toward the other returnportion (122) and each return portion (122) has a length dimension and a radiusof curvature reducing stress concentrations. Preferably, the length dimensionof the arcuate return portion (122) is in excess of twice the thickness. The lateraldistance, LD, to which the bend-inducing structures (113) is formed in the sheetaway from the bend line (115) is preferably minimized by small radius arcs (125)which connect the return portions (122) to the remainder of the bend-inducingstructures (113). A method of forming a structure (131) from a sheet of material(111) to resist cyclical loading is also disclosed, as is a method to increasethe fatigue resistance of a structure (131) formed by bending a sheet of material(111) along a bend line (115) having a plurality of bend-inducing structures(113).