Methods and apparatus for manufacture of moment connection components

1. A collar flange assembly welding fixture, comprising:

a stand having a plurality of circumferential bearings equidistant from an axis of rotation;

a circular mount structure rotatably supported by the circumferential bearings; and

a support assembly configured for mounting on the circular mount structure, and including a plate structure and a pair of collar corner simulators;

a lock mechanism having a free mode in which the circular mount structure is rotatable about the axis and a locked mode in which the circular mount structure is not rotatable, the lock mechanism being configured to prevent removal of a flange assembly held by the support assembly when the lock mechanism is in the free mode;

wherein the stand, circular mount structure, and support assembly are configured to provide access to a front side and a back side of a collar flange assembly held by the support assembly.

2. The fixture of claim 1 , wherein the plate structure has a central opening.

3. The fixture of claim 2 , wherein the plate structure includes an array of circular and elongate apertures for fastening the pair of collar corner simulators to the plate structure.

4. The fixture of claim 3 , wherein each circular aperture is a threaded aperture configured to receive a bolt, and each elongate aperture is a slot configured to receive a pin.

5. The fixture of claim 1 , wherein the circular mount structure includes a handle for manual rotation of the mount structure relative to the stand.

6. The fixture of claim 1 , wherein the lock mechanism is configured to allow removal of a flange assembly held by the support assembly only when the support assembly is in an upright rotational orientation and the lock mechanism is in the locked mode.

7. A collar flange assembly welding fixture, comprising:

a plate structure having a central opening that provides welding access from both a front side and a back side of the welding fixture;

a pair of collar corner simulators attached to the plate structure and configured to support top and bottom collar flange members on opposite ends of a bridging element; and

an arm device, attached to a back side of the plate structure, extending through the central opening, and configured to at least partially support the bridging element.

8. The fixture of claim 7 , wherein the arm device is removably attached to the plate structure.

9. The fixture of claim 8 , wherein the arm device is magnetically attached to the plate structure.

10. The fixture of claim 7 , wherein each collar corner simulator includes a pin that fits into a slot in the plate structure, the slot having a long axis orthogonal to a long axis of the plate structure.

11. The fixture of claim 10 , wherein each collar corner simulator further includes a hole horizontally adjacent the pin, for receiving a bolt to fasten the simulator to the plate structure.

12. The fixture of claim 7 , wherein each collar corner simulator includes a stop member extending outward from a lower end portion, the stop member being configured to locate a lower flange member along a Z-axis.

13. A method of welding a collar flange assembly, comprising:

positioning the first and second collar corner simulators of the collar flange assembly welding fixture of claim 9 on the plate structure of the welding fixture;

receiving top and bottom flange members between the first and second collar corner simulators;

positioning a bridge element between the top and bottom flange members;

welding the flange members to the bridge element through the opening in the plate structure.

14. The method of claim 13 , further comprising:

rotating the plate structure to access multiple weld sites.

15. The method of claim 13 , wherein positioning the first and second collar corner simulators includes setting a Z-axis location of each collar corner simulator by inserting a pin on the simulator into an oblong hole in the plate structure, the oblong hole having a long axis orthogonal to a long axis of the plate structure.

16. The method of claim 15 , wherein positioning the first and second collar corners simulators includes setting an X-axis location of each collar corner simulator by fastening a bolt through a round hole in the simulator to a first threaded hole in the plate structure.

17. The method of claim 16 , wherein positioning the first and second collar corners simulators includes setting a Y-axis location of each collar corner simulator by fastening a bolt through an oblong hole in the simulator to a second threaded hole in the plate structure, the oblong hole in the simulator having a long axis parallel to the long axis of the plate structure.