Systems, methods, and apparatuses for modification of the structural capacity of space frames

Abstract

Systems, methods, and apparatuses for effectively increasing the structural capacity of space frames. In various embodiments, a space frame may be post-tensioned with interior cables that attach to nodes and form unique load transfer paths, thereby redistributing the member stresses and generally creating uniformity amongst stress types. Further, in various embodiments, variable space frame geometry may be employed to match the structural capacity of the space frame with the structural loads on the same, thereby modifying a space frame to comprise one or more empty bays or stretch bays.

What is claimed is: 
     
         1 . A three-dimensional truss, comprising:
 a plurality of bays, wherein the plurality of bays are defined by:
 two parallel top chords affixed by a plurality of top chord struts, wherein the two parallel top chords define a first end and a second end; and 
 at least one bottom chord affixed to each of the two parallel top chords by a plurality of bottom chord struts, wherein the at least one bottom chord is parallel to each of the two parallel top chords and is supported by at least two supports defining a midspan between the at least two supports; 
   a first modified bay at the first end; and   a second modified bay in the midspan.   
     
     
         2 . The three-dimensional truss of  claim 1 , wherein the first modified bay at the first end comprises a two-dimensional bay or a stretch bay. 
     
     
         3 . The three-dimensional truss of  claim 2 , wherein the two-dimensional bay consists of the two parallel top chords, at least one of the plurality of top chord struts, none of the plurality of bottom chord struts, and none of the at least one bottom chord. 
     
     
         4 . The three-dimensional truss of  claim 3 , wherein the stretch bay comprises the two-dimensional bay and at least two stretch struts extending from the at least one bottom chord in an adjacent bay of the plurality of bays across the two-dimensional bay to the two parallel top chords. 
     
     
         5 . The three-dimensional truss of  claim 4 , further comprising a third modified bay at the first end, wherein the first modified bay at the first end comprises the stretch bay and the third modified bay at the first end comprises the two-dimensional bay. 
     
     
         6 . The three-dimensional truss of  claim 5 , further comprising a fourth modified bay at the first end, wherein the fourth modified bay at the first end comprises another two-dimensional bay. 
     
     
         7 . The three-dimensional truss of  claim 6 , further comprising at least two modified bays at the second end, wherein the at least two modified bays at the second end comprise a second stretch bay and a second two-dimensional bay. 
     
     
         8 . The three-dimensional truss of  claim 1 , wherein the at least one modified bay in the midspan comprises a two-dimensional bay or a stretch bay. 
     
     
         9 . The three-dimensional truss of  claim 8 , wherein the two-dimensional bay consists of the two parallel top chords, at least one of the plurality of top chord struts, none of the plurality of bottom chord struts, and none of the at least one bottom chord. 
     
     
         10 . The three-dimensional truss of  claim 9 , wherein the stretch bay comprises the two-dimensional bay and at least two stretch struts extending from the at least one bottom chord in an adjacent bay of the plurality of bays across the two-dimensional bay to the two parallel top chords. 
     
     
         11 . The three-dimensional truss of  claim 10 , further comprising a third modified bay in the midspan, wherein the second and third modified bays in the midspan comprise stretch bays. 
     
     
         12 . The three-dimensional truss of  claim 10 , further comprising a third modified bay in the midspan, wherein the second and third modified bays in the midspan comprise two-dimensional bays. 
     
     
         13 . The three-dimensional truss of  claim 10 , further comprising a third and fourth modified bay in the midspan, wherein the second and third modified bays in the midspan comprise stretch bays and the fourth modified bay in the midspan comprises the two-dimensional bay. 
     
     
         14 . The three-dimensional truss of  claim 1 , further comprising a tensioned cable affixed to the at least one bottom chord and one of the two parallel top chords, wherein the tensioned cables transfers loads between the at least one bottom chord and the one of the two parallel top chords. 
     
     
         15 . The three-dimensional truss of  claim 14 , wherein the tensioned cable is affixed to the at least one bottom chord directly above one of the at least two supports. 
     
     
         16 . The three-dimensional truss of  claim 15 , wherein the tensioned cable is affixed to the one of the two parallel top chords in two locations on either side of the one of the at least two supports. 
     
     
         17 . The three-dimensional truss of  claim 14 , wherein the tensioned cable is affixed to the one of the two parallel top chords directly above one of the at least two supports. 
     
     
         18 . The three-dimensional truss of  claim 17 , wherein the tensioned cable is affixed to the at least one bottom chord in two locations on either side of the one of the at least two supports. 
     
     
         19 . The three-dimensional truss of  claim 1 , wherein one or more solar panels are affixed to the tops of the two parallel top chords 
     
     
         20 . A method for modifying the structural capacity of a three-dimensional truss, comprising the steps of:
 assessing one or more anticipated load conditions of the three-dimensional truss;   determining, based on the assessed one or more anticipated load conditions, that the three-dimensional truss should comprise a first modified bay at a first end and a second modified bay in a midspan; and   installing the three-dimensional truss, wherein the three-dimensional truss comprises:
 a plurality of bays, wherein the plurality of bays are defined by:
 two parallel top chords affixed by a plurality of top chord struts, wherein the two parallel top chords define the first end and a second end; and 
 at least one bottom chord affixed to each of the two parallel top chords by a plurality of bottom chord struts, wherein the at least one bottom chord is parallel to each of the two parallel top chords and is supported by at least two supports defining the midspan between the at least two supports; 
 
 the first modified bay at the first end; and 
 the second modified bay in the midspan. 
   
     
     
         21 . The method of  claim 20 , further comprising the steps of:
 determining, based on the assessed one or more anticipated load conditions, that the three-dimensional truss should comprise a tensioned cable affixed to the at least one bottom chord and one of the two parallel top chords, wherein the tensioned cables transfers loads between the at least one bottom chord and the one of the two parallel top chords; and   after installing the three-dimensional truss, installing the tensioned cable.   
     
     
         22 . A three-dimensional truss, comprising:
 two parallel top chords affixed by a plurality of top chord struts, wherein the two parallel top chords define a first end and a second end; and   at least one bottom chord affixed to each of the two parallel top chords by a plurality of bottom chord struts, wherein the at least one bottom chord is parallel to each of the two parallel top chords and is supported by at least two supports defining a midspan between the at least two supports;   a plurality of top chord nodes along the two parallel top chords to which the plurality of top chord struts and the plurality of bottom chord struts are affixed; and   a plurality of bottom chord nodes along the at least one bottom chord to which the plurality of bottom chord struts are affixed, wherein the at least one bottom chord terminates at a particular bottom chord node of the plurality of bottom chord nodes and the first end extends past the particular bottom chord node such that the two parallel top chords do not terminate in line with the at least one bottom chord.   
     
     
         23 . The three-dimensional truss of  claim 22 , further comprising:
 a first stretch strut affixed to the particular bottom chord node that extends to the first end, wherein the first stretch strut is affixed to a first particular top chord node of the plurality of top chord nodes on a first top chord of the two parallel top chords; and   a second stretch strut affixed to the particular bottom chord node that extends to the first end, wherein the second stretch strut is affixed to a second particular top chord node of the plurality of top chord nodes on a second top chord of the two parallel top chords.