A manufacturing method of a member according to an aspect of the present invention is a manufacturing method of a member including a specific three-dimensional tubular portion, the manufacturing method including: a U-forming step of performing U-forming on metal material sheet using a U-forming die and punch including a U-forming punch to manufacture a U-formed article having a recessed cross-sectional shape; and an O-forming step of causing side end portions of the U-formed article to abut each other by an O-forming die to form abutting portions, in which a forming condition ratio a=Du/Do is set to 0.85 to 0.95.

Spiral forming methods can be used to join edges of a rolled material along a spiral joint to form conical and/or cylindrical structures. Alignment of the edges of the rolled material can be controlled in a wrapping direction as the material is being joined along the spiral joint to form the structure. By controlling alignment of the edges of the material as the edges of the material are being joined, small corrections can be made over the course of forming the structure facilitating control over geometric tolerances of the resulting spiral formed structure.

A control system for forming a tapered structure includes a sensor providing feedback for a machine for forming a tapered structure including at least three rolls having at least one bend roll and at least two guide rolls. The guide rolls may include rollette banks having a plurality of rollettes. The machine may also include an adjustment mechanism to position at least one of the rolls, where a diameter of the tapered structure being formed is controlled by relative positions of the rolls. The machine may also include a joining element to join edges of a stock of material together as it is rolled through the rolls to form the tapered structure. The control system may also include a controller to receive feedback from the sensor and to send a control signal based on the feedback to the adjustment mechanism for positioning at least one of the rolls.

A manufacturing method for producing a tower segment, a tower portion and a tower section for a tower, in particular for a tower of a wind power installation. A tower segment, a tower portion and a tower section for a tower, in particular for a tower of a wind power installation, to a tower, and to a wind power installation. The manufacturing method comprises: providing a plate that extends in the longitudinal direction and, orthogonally thereto, in a circumferential direction, wherein the extent in the longitudinal direction is larger than the extent in the circumferential direction; and rolling the plate for incorporating a thickness profile along a longitudinal direction of the plate, wherein the rolling comprises: incorporating a first constant portion having a substantially constant first thickness which differs from a substantially constant second thickness of a second constant portion that in the longitudinal direction is disposed so as to be substantially parallel to said first constant portion; and bending the plate in the circumferential direction.

Spiral forming methods can be used to join edges of a rolled material along a spiral joint to form conical and/or cylindrical structures. Alignment of the edges of the rolled material can be controlled in a wrapping direction as the material is being joined along the spiral joint to form the structure. By controlling alignment of the edges of the material as the edges of the material are being joined, small corrections can be made over the course of forming the structure facilitating control over geometric tolerances of the resulting spiral formed structure.

A method for creating a tapered spiral welded conical structure where the overall shape of the cone is first graphically slit axially and unwrapped, and then a series of construction arcs and lines are created to form the edge lines of a strip that can then be wrapped (rolled) to form a tapered conical structure. The edges of the spirally wound strip can be welded together, and a very large conical structure can thus be achieved. Various construction options are presented from a constant width strip to strip made from straight segments. Equations are given for the formation of the strips to enable those skilled in the art of spiral welded tubing to practice the invention.

A method of production of a shaped article able to suppress occurrence of shaping defects, that is, a method of production of a shaped article including a first step of press-forming a metal plate (1a) into a U-shape to obtain a U-shaped article (1b) having a bottom part (2) straight extending in a longitudinal direction and a second step of press-forming the U-shaped article (1b) to bend it in the longitudinal direction so that the bottom part (2) of the part projects to the inside and obtain a U-cross-section bent article (1c).

Feeding stock used to form a tapered structure into a curving device such that each point on the stock undergoes rotational motion about a peak location of the tapered structure; and the stock meets a predecessor portion of stock along one or more adjacent edges.

A method for manufacturing a pipe includes: press-forming a plate member into a U shape; and press-forming the plate member formed into the U shape into an O shape. The pipe includes a pipe body and a tapered part tilted radially inward and protruding from one end of the pipe body. Before the plate member is press-formed into the U shape, a boundary between a portion of the plate member corresponding to the pipe body and a portion of the plate member corresponding to the tapered part is pressed from a surface of the plate member corresponding to an inner peripheral surface of the pipe to bend the portion of the plate member corresponding to the tapered part toward the surface of the plate member corresponding to the inner peripheral surface of the pipe.

Tubular structures, systems, and methods are generally directed to support structures having structural properties similar to thick-walled structures while being formed using materials having thickness amendable to rolling and welding and, thus, useful for rapid and cost-effective fabrication.