Structural members and related methods and systems
Embodiments disclosed herein relate to structural, seismic beams and columns as well as to structures including such beams and columns. The seismic beams and columns may be sized, shaped, or otherwise configured to produce approximately even or uniform load distribution (e.g., during a seismic event and/or wind loading event).
1. A beam for fabrication of a moment-resisting frame, the beam comprising:
one or more webs extending along a longitudinal axis, the one or more webs including a first side and a second, opposite side; and
a plurality of flanges connected to the one or more webs and extending along the longitudinal axis, at least one flange of the plurality of flanges being positioned on the first side of the one or more webs and at least another flange of the plurality of flanges being positioned on the second, opposite side of the one or more webs, each flange of the plurality of flanges having an approximately planar major side that is oriented approximately perpendicular to the one or more webs, each approximately major side having a width that gradually decreases along the longitudinal axis from a first location to a second location, the width of each approximately major side gradually increases along the longitudinal axis from the second location to a third location, the second location being positioned between the first location and the third location; and
wherein the one or more webs and the plurality of flanges form a generally tubular shape.
2. A moment-resisting frame, comprising:
a first vertical beam;
a second vertical beam; and
a first horizontal beam rigidly connected at a first end thereof to a first connection location on the first vertical beam and at a second end thereof to a second connection location on the second vertical beam;
wherein the first vertical beam, second vertical beam, and the first horizontal beam have a varying moment of inertia that decreases along a longitudinal axis thereof from a first location to a second location, the first vertical beam having a highest moment of inertia at the first connection location, and the second vertical beam having a highest moment of inertia at the second connection location.
3. The moment-resisting frame of claim 2 wherein the moment of inertia of at least one of the first vertical beam, second vertical beam, or the first horizontal beam increases along the longitudinal axis from the second location to a third location.
4. A moment-resisting frame, comprising:
a first vertical beam, including:
a first vertical web;
a first vertical flange connected to the first vertical web, the first vertical flange having a varying width, the varying width being greatest at a connection location and gradually decreasing along a longitudinal axis of the first vertical beam in a first direction from the connection location to a reduced width location;
a second vertical flange connected to the first vertical web;
a second vertical beam oriented approximately parallel to the first vertical beam;
a first horizontal beam rigidly connected at a first end thereof to the connection location on the first vertical beam and at a second end thereof to a connection location on the second vertical beam, the first horizontal beam including:
a first horizontal web having approximately vertical orientation;
a first horizontal flange connected to the first horizontal web and having an approximately horizontal orientation, the first horizontal flange having a width that is greater at and/or near the first end than at an intermediate location between the first end and the second end; and
a second horizontal flange connected to the first web and having an approximately horizontal orientation.
5. The moment-resisting frame of claim 4 wherein the width of the first horizontal flange near the second end is greater than the width of the first horizontal flange at the intermediate location.
6. The moment-resisting frame of claim 5 wherein the intermediate location is approximately midway between the first end and the second end of the first horizontal beam.
7. The moment-resisting frame of claim 4 wherein the second horizontal flange has a greater width at and/or near the first end than at the intermediate location between the first end and the second end.
8. The moment-resisting frame of claim 5 wherein at least a portion of at least one of the first horizontal flange or the second horizontal flange has a generally tapered shape.
9. The moment-resisting frame of claim 8 wherein at least one of the first horizontal flange or the second horizontal flange has approximately linear sides.
10. The moment-resisting frame of claim 8 wherein at least one of the first horizontal flange or the second horizontal flange has nonlinear sides.
11. The moment-resisting frame of claim 5 wherein the second horizontal flange has a width that is greater at and/or near the second end than the width of the second horizontal flange at the intermediate location.
12. The moment-resisting frame of claim 11 wherein the first horizontal beam includes a second web connecting the first and second horizontal flanges together.
13. The moment-resisting frame of claim 12 wherein the first horizontal beam has a generally tubular shape.
14. The moment-resisting frame of claim 5 wherein the second vertical beam includes:
one or more webs; and
a plurality of flanges connected to the one or more webs, at least one of the at least one flange having a first width at the connection location and a second width at an intermediate location that is spaced apart from the connection location, the second width being smaller than the first width.
15. The moment-resisting frame of claim 14 , further comprising a second horizontal beam rigidly connected at a first end thereof to a second connection location on the first vertical beam and at a second end thereof to a second connection location on the second vertical beam.
16. The moment-resisting frame of claim 4 wherein the width of the first vertical flange of the first vertical beam gradually increases in the first direction from the reduced width location to another location.
17. The moment-resisting frame of claim 4 wherein a first portion of at least one of the first vertical beam or the second vertical beam extends between the connection location and the intermediate location and has a generally tapered shape.
18. The moment-resisting frame of claim 17 wherein a second portion of at least one of the first vertical beam or the second vertical beam extends between the second connection location and the intermediate location and has a generally tapered shape.