Systems, methods and apparatus for resilient Gert Haunch moment frame connection

A coupling apparatus comprising:

• a haunch including a beam segment having:
• a haunch length less than a length of a beam;
• a first haunch end;
• a second haunch end opposite the first haunch end;
• and
• a haunch cross sectional size substantially equal to a cross-sectional size of the beam;
• a bend plate coupled to the first haunch end, the bend plate extending across a depth of the haunch and further extending across a yielding length and a retainer plate length of a retainer plate;
• a spacer plate disposed between the bend plate and a first side of a column, the spacer plate having a spacer plate thickness equal to a yielding gap width, the spacer plate having a spacer plate length equal to the length of the retainer plate;
• at least one removable haunch threaded fastener securing the haunch to a first side of the beam, the at least one haunch threaded fastener extending through the first side of the haunch and the first side of the beam, wherein the bend plate is offset from a first side of the column by the yielding width;
• the retainer plate disposed on an opposite side of the bend plate from the spacer plate and offset from a bottom of the haunch by the yielding length;
• at least one retainer threaded fastener passing through the retainer plate, the bend plate, the spacer plate and at least one side of the column, the at least one retainer threaded fastener securing the retainer plate, the bend plate, the spacer plate to the at least one side of the column;
• a shear tab coupled to the first side of the column, the shear tab including a shear tab pivot and an upper shear tab slot formed a first distance above a centerline of the pivot and a lower shear tab slot formed the first distance below the centerline of the pivot;
• a substantially round rotation opening formed in the beam corresponding to and aligned with the shear tab pivot, the pivot opening having a diameter substantially equal to a diameter of the shear tab pivot;
• and
• an upper shear tab threaded fastener and a lower shear tab threaded fastener passing through the beam and securing the beam to the upper and lower shear tab slots.

A method of forming a flexible connection between a beam and a column comprising:

• removably connecting a first haunch side of the haunch to a first side of the beam;
• securing a bend plate to a first end of the haunch, the bend plate extending away from a second haunch side of the haunch a sum of a yielding length and a retaining plate length, coupling the bend plate to a spacer plate and the first side of the column;
• pivotally coupling a web of the beam to the first side of the column;
• and
• securing a top plate to the second side of the beam, the top plate including a column opening encompassing the column.