Methods for forming composite structures

A method for forming a composite structure including positioning a composite sheet (140) adjacent to a die opening (310), constraining a portion of the composite sheet between a first forming surface (214) and a second forming surface (314) being spaced apart by a gap dis- tance being substantially equal to or greater than the sheet thickness, and urging the composite sheet through the die opening and along a third forming surface (312) to form a composite bottom from the com- posite sheet. According to another aspect the composite sheet is deformed into a deformed sheet (240) comprising a radius portion (250) disposed be- tween an inner portion (246) and an outer portion (248), the latter comprising an elastic radius (252); and removing the elastic radius from the outer portion of the deformed sheet to form a composite bot- tom. According to yet another aspect processing steps are performed con- currently on a plurality of sheets.