Moment frame connector

Abstract

A lateral bracing system is disclosed for affixing a column to a beam in a construction. The lateral bracing system includes a pair of buckling restraint blocks, one each affixed to a top and bottom flange of a beam. Each buckling restraint block includes one or more bores formed through a center of the block. The lateral bracing system further includes at least one yield link for each buckling restraint block. Each yield link includes a first end affixed to the column, and a second end fit through a bore in a buckling restraint block and affixed to an end of the buckling restraint block.

1 . A lateral bracing system for use in constructions, the lateral bracing system comprising:
 a structural frame having a beam and a column; and   a buckling restraint block affixed to the beam; and   a yield link, threaded into the buckling restraint block and bolted to the column, the yield link capable of yielding in tension and compression to dissipate stress within the frame upon a lateral load applied to the structural frame.   
   
   
       2 . A lateral bracing system as recited in  claim 1 , wherein the buckling restraint block and yield link between the beam and column allows omission of a lateral-torsional buckling restraint system on the beam. 
   
   
       3 . A construction including a beam and a column, the construction comprising:
 a buckling restraint block capable of being affixed to an end of the beam, the buckling restraint block including a first end nearest the end of the beam when the block is affixed to the beam, a second end opposite the first end and a bore between the first and second ends; and   a yield link including a first end capable of being affixed to the column, and a second end fit through the bore in the buckling restraint block and capable of being affixed to the second end of the buckling restraint block, the yield link capable of yielding in tension and compression to dissipate stress within the frame upon a lateral load applied to the beam and/or column.   
   
   
       4 . A construction as recited in  claim 1 , wherein the second end of the yield link is threaded to mate with threads on the second end of the buckling restraint block. 
   
   
       5 . A construction as recited in  claim 1 , wherein the yield link includes a middle section having a lower strength than the first and second ends, the yield link yielding at the middle section upon a given tensile force. 
   
   
       6 . A construction as recited in  claim 5 , wherein the middle section has a smaller diameter than the first and second ends. 
   
   
       7 . A construction as recited in  claim 1 , further comprising one or more ribs of larger diameter in a middle section of the yield link, the one or more ribs opposing buckling of the yield link by coming into contact with walls of the buckling restraint block defining the bore. 
   
   
       8 . A construction as recited in  claim 7 , wherein the one or more ribs comprise three ribs. 
   
   
       9 . A construction as recited in  claim 1 , wherein the second end of the yield link has a larger diameter than the first end of the yield link. 
   
   
       10 . A construction, comprising:
 a column;   a beam;   a shear tab affixed between the column and beam; and   a lateral bracing system affixed between the column and beam, including:
 a pair of buckling restraint blocks, one each on a top and bottom flange of the beam, each buckling restraint block including a first end affixed to an end of the beam, a second end opposite the first end and at least one bore between the first and second ends; and 
 a pair of yield links, each yield link including a first end affixed to the column, and a second end fit through the bore in one of the buckling restraint blocks and affixed to the second end of one of the buckling restraint blocks, a yield link of the pair of yield links capable of yielding in tension and compression to dissipate stress within the frame upon a lateral load applied to the beam and/or column. 
   
   
   
       11 . A construction as recited in  claim 10 , wherein each buckling restraint block includes a pair of parallel bores. 
   
   
       12 . A construction as recited in  claim 11 , wherein each bore in a buckling restraint block includes yield link therethrough. 
   
   
       13 . A construction as recited in  claim 10 , wherein the second end of each yield link is threaded to mate with threads on the second end of each buckling restraint block. 
   
   
       14 . A construction as recited in  claim 10 , wherein each yield link includes a middle section having a smaller diameter than the first and second ends. 
   
   
       15 . A construction as recited in  claim 10 , further comprising one or more ribs of larger diameter in a middle section of each yield link, the one or more ribs opposing buckling of the yield link by coming into contact with walls of the buckling restraint block defining the bore. 
   
   
       16 . A construction as recited in  claim 15 , wherein the one or more ribs comprise three ribs. 
   
   
       17 . A method of assembling a frame having a beam, column and lateral bracing system therebetween, comprising the steps of:
 (a) affixing a buckling restraint block to a first one of the beam and column;   (b) affixing a yield link to the buckling restraint block; and   (c) bolting the yield link to a second one of the beam and column.   
   
   
       18 . A method as recited in  claim 17 , said step (a) of affixing a buckling restraint block to a first one of the beam and column comprising the step of affixing the buckling restraint block by one of gluing or welding. 
   
   
       19 . A method as recited in  claim 17 , said step (b) of affixing a yield link to the buckling restraint block comprising the step of screwing a threaded end of the yield link into a threaded portion of the buckling restraint block. 
   
   
       20 . A method as recited in  claim 17 , said step (a) of affixing a buckling restraint block to a first one of the beam and column comprising the step of affixing the buckling restraint block to one of the beam and column prior to the beam and column arriving at a worksite. 
   
   
       21 . A method as recited in  claim 17 , the buckling restraint block affixed in said step (a) and the yield link affixed in said step (b) together resisting lateral deflection of the beam relative to the column, but yielding at a center portion of the yield link upon loads above a threshold level. 
   
   
       22 . A method as recited in  claim 17 , the buckling restraint block affixed in said step (a) and the yield link affixed in said step (b) together resisting lateral deflection of the beam relative to the column placing tensile forces on the yield link by the yield strength of the yield link. 
   
   
       23 . A method as recited in  claim 17 , the buckling restraint block affixed in said step (a) and the yield link affixed in said step (b) together resisting lateral deflection of the beam relative to the column placing compressive forces on the yield link by the yield link being constrained against buckling by the walls of the bore of the buckling restraint block.