This invention generally relates to structural members, and more specifically to structural members with self-reinforced openings.
It is sometimes necessary to penetrate structural members, such as I-beams, during the construction of a structure to create openings for mechanical/electrical ducts and/or cables, etc. to pass through. However, such openings typically decrease the strength (flexure, shear, and axial) of the affected structural member, requiring supplemental reinforcement of the affected region.
One embodiment of the invention provides a self-reinforced structural member having a vertical web between a first horizontal flange and a second horizontal flange. The vertical web may include a self-reinforced opening.
In one aspect, at least one reinforcement flange may be formed from a cut portion of the web to reinforce the self-reinforced opening.
In another aspect, the at least one reinforcement flange may extend from a horizontal edge of the self-reinforced opening in a tangential direction with respect to the vertical web.
In another aspect, the at least one reinforcement flange may extend from a horizontal edge of the self-reinforced opening in a vertical direction.
In another aspect, the at least one reinforcement flange may extend from a vertical edge of the self-reinforced opening in a horizontal direction.
Another embodiment of the invention provides a method to create a self-reinforced structural member. A first cut may be created through a web of a structural member. A second and third cut may be created through the web of a structural member. The second and third cuts may intersect the first cut. A portion of the web between the first, second and third cuts may be bent to form a reinforcement flange.
In one aspect, a portion of the reinforcement flange may be welded to the web and/or at least one of the first and second horizontal flanges.
These and other embodiments of the invention are described in further detail below with reference to the following figures.
A structural member with a self-reinforced opening is disclosed. The self-reinforced opening is generally constructed from elements of a pre-formed structural member, such as an I-beam. The self-reinforced opening may be formed to increase and/or maintain the flexural and/or shear strength along portions of the structural member. The self-reinforced opening can offer a more environmentally compatible solution to prior art methods, which involved cutting and discarding portions of a structural member and placing new portions of material along conduit openings. Thus, a self-reinforced opening suffers from no significant waste or addition of material, and reduces or eliminates welding.
The implementation of the self-reinforced opening is not limited to providing conduit pathways. As the self-reinforced opening can increase flexural and/or shear strength along portions of the structural member, the self-reinforced opening can be strategically placed in structural members to compensate for expected high loads, which would otherwise not be possible for the same structural member with no self-reinforced openings. Accordingly, the use of the self-reinforced opening can avoid the use of heavier structural members which would otherwise be needed, and which results in less material being used and lowers the overall weight of the structure.
The structural member 100 has been cut in order to form a reinforced opening 112. The structural member 100 may be cut, for example, using a cutting-torch, cutting-laser, or water-jet cutting machinery. The reinforced opening 112 may be formed by bending portions of the web from the horizontal and vertical cuts extending through the web.
The self-reinforced opening 112 minimally decreases flexural strength of the structural member since the web contributes little to flexural strength. The horizontal flange 102 and a second horizontal flange 104 contribute to most of the flexural strength possessed by the structural member 100. The reinforcement flanges 114 increase the flexural strength at the self-reinforced opening 112, as compared to an opening with no reinforcement. Thus, the reinforcement flanges 114 compensate for the flexural strength loss due to the self-reinforced opening 112, and may in some cases create a greater flexural strength as compared to a structural member with no openings.
Larger openings (extending in the vertical direction) accordingly result in larger reinforcement flanges which compensate for the otherwise larger loss in flexural strength. Thus, very large openings (e.g., more than 50% of the web) are possible accompanied by little flexural strength loss or even some appreciable flexural strength gain. Flexural demand is high in some regions such as the mid-span of a simply supported beam; accordingly, the self-reinforced opening 112 shown in
The structural member of
Larger openings (extending in the vertical direction) accordingly result in larger reinforcement flanges which compensate for the otherwise larger loss in shear strength. Thus, very large openings (e.g., up to 50%) of the web are possible, which may be accompanied by virtually no shear strength loss. Shear demand is high in some regions, such as the ends of a simply supported beam, accordingly, the self-reinforced opening 206 shown in
In some embodiments, a plurality of openings can be made in the same member span using Section B-B of
Portions 302 and 304 are bent about the horizontal edges of the self-reinforced opening 310 to create two reinforcement flanges in the flexure region as shown in
Portions 306 and 308 are bent about the vertical edges of the self-reinforced opening 310 as shown in Section E-E, which increases the shear strength in the shear region. Accordingly, portions 306 and 308 extend from vertical edges of the self-reinforced opening 310 in horizontal directions. Edges of the portions 306, 308 may be welded to the web. This arrangement increases the shear strength about portions 306 and 308, since the cross-sectional area has been increased.
The above description is illustrative and is not restrictive. Many variations of the invention will become apparent to those skilled in the art upon review of the disclosure. For example, in some embodiments varying cross-sections may be implemented to increase/maintain flexural and/or shear strength of pre-formed composite materials, such as wood, concrete, plastic, composites, and steel/concrete structural members. In another example, self-reinforced openings are placed on the main flanges of an I-beam, as opposed to the web. In another example, a self-reinforced opening is non-symmetrical, and thus includes only one reinforcement flange there along. In another example, a self-reinforced opening is used to redirect yield along specific areas of a structural member in order to prevent catastrophic failure of a structure. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the pending claims along with their full scope or equivalents.
One or more features from any embodiment may be combined with one or more features of any other embodiment without departing from the scope of the invention.
A recitation of “a”, “an” or “the” is intended to mean “one or more” unless specifically indicated to the contrary.
This application claims the benefit of U.S. Provisional Application No. 61/304,384, filed on Feb. 12, 2010, the entirety of which is incorporated by reference herein.
Number | Date | Country | |
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61304384 | Feb 2010 | US |