Patent Application
20250129593
The present invention relates to a moment frame connector system designed to connect a beam to a column in constructions, and in particular to one-piece moment frame connector formed from a section of structural steel.
Lateral loads due to natural phenomena such as high winds can have devastating effects on the structural integrity of buildings, bridges and other constructions. Lateral forces generated during such natural phenomena may cause the top portion of a wall to move laterally with respect to the bottom portion of the wall, which movement can result in damage or structural failure of the wall and, in some instances, collapse of the building. One of the critical components in the structural framework of buildings is the connection between beams and columns. In conventional construction, this connection is achieved through various methods such as welding, bolting, or adhesive bonding. However, if not made strong enough, these systems can fall short in high wind areas, where the large forces acting on the structure can lead to joint failure, compromising the structural integrity of the entire building. The stiffness of these connections are also important to the behavior of the lateral system and in protecting architectural components.
One method of providing a high-strength connection effective at resisting lateral loads is to provide T-shaped connectors including vertical sections affixed to the column and horizontal sections affixed to the top and bottom flanges of the beam. A typical T-shaped connector includes a vertical plate and a horizontal plate welded or otherwise affixed orthogonally to the vertical plate. Currently, the horizontal and vertical plates are formed from different pieces of steel, each having different properties. Moreover, welding of the vertical plate to the horizontal plate is subject to imperfections, unwanted heat effects and added labor. Even if done correctly, the weld can be less ductile than the other portions of steel in the structural connectors, and can abruptly fail under large lateral loads.
The present technology relates to a one-piece structural connector formed from a single piece of structural steel such as an I-beam or standard structural W-shape beam. Initially, a section, or blank, may be cut from a beam. The blank may be severed transverse to the length of the beam, so that the blank includes first and second flanges connected by a web. In embodiments, the web may be cut in the middle to form a pair of one-piece moment frame connectors, each having a vertical plate and a horizontal plate. In embodiments, the pair of moment frame connectors may be used in a single moment frame connection, one connector at the top and the other connector at the bottom. This ensures that the two connectors have the same internal composition and as such, the same response to lateral loads.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the Background.
The present technology, roughly described, relates to a one-piece moment frame connector formed from a single piece of structural steel such as an I-beam, a wide-flange I-beam or a standard structural W-shaped beam. Initially, a blank may be cut from a beam transverse to the length of the beam, so that the blank includes first and second flanges connected by a web. The one-piece moment frame connector may then be cut from the blank to include a vertical plate formed from one of the flanges of the beam, and a horizontal plate formed from a portion of the web of the beam. A single blank from the beam may be cut in half to form a pair of identical moment frame connectors.
Forming the components used in a moment frame connector from a single piece of a beam provides several advantages. First, having the vertical plate integrally formed with the horizontal plate avoids the need for a weld, thus removing the possibility of human error in forming the weld, and brittleness at the weld site. Second, in embodiments, top and bottom connectors from the same blank may be used in a moment frame connector. When steel is heated in a certain way, a grain of the steel may align to polar north. Forming the top and bottom moment frame connectors from a single piece of steel where all of the grain is aligned ensures uniform properties and response across the top and bottom moment frame connectors.
It is understood that the present invention may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the invention to those skilled in the art. Indeed, the invention is intended to cover alternatives, modifications and equivalents of these embodiments, which are included within the scope and spirit of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be clear to those of ordinary skill in the art that the present invention may be practiced without such specific details.
The terms “top” and “bottom,” “upper” and “lower” and “vertical” and “horizontal,” and forms thereof, as may be used herein are by way of example and illustrative purposes only, and are not meant to limit the description of the technology inasmuch as the referenced item can be exchanged in position and orientation. Also, as used herein, the terms “substantially” and/or “about” mean that the specified dimension or parameter may be varied within an acceptable manufacturing tolerance for a given application. In one embodiment, the acceptable manufacturing tolerance is ±0.15 mm, or alternatively, ±2.5% of a given dimension.
For purposes of this disclosure, a connection may be a direct connection or an indirect connection (e.g., via one or more other parts). In some cases, when a first element is referred to as being connected, affixed, mounted or coupled to a second element, the first and second elements may be directly connected, affixed, mounted or coupled to each other or indirectly connected, affixed, mounted or coupled to each other. When a first element is referred to as being directly connected, affixed, mounted or coupled to a second element, then there are no intervening elements between the first and second elements (other than possibly an adhesive or melted metal used to connect, affix, mount or couple the first and second elements).
The flanges may be formed in a so-called standard structural W-shape, where interior surfaces 202a, 204a of the flanges 202 and 204 are orthogonal to the surfaces of the web 206 (
In step 100, a section of the beam 200 is cut from the beam in a direction transverse to a length (L,
In step 104, bolt holes may be formed in the first flange 202, the second flange 204 and the web 206. For example, as shown in
In step 106, a transverse cut may be made across the width of the web 204 to cut the blank 200 in half as shown in
The flange (202 in
After being severed from the blank 210, the T-plate connectors 216 may be cleaned and painted or powder coated, for example with PMS172 orange, in step 108. Step 108 may include blasting the T-plate connectors 216 to remove any slag from plasma or other elevated temperature cutting processes. It may also remove scale which may result from the rolling fabrication process of the beam 200. The cleaning step 108 may also remove any rust from the T-plate connectors 216.
It is understood that some of the above-described steps may be performed in a different order in further embodiments. For example, it is understood that the sequence of steps including the formation of the bolt holes (step 104) and the transverse cut (step 106) may be reversed in further embodiments.
The vertical plates 202, 204 of the respective top and bottom T-plate connectors 216 may be connected to an inner flange of the column 222 as by bolt fasteners 230 through bolt holes 212. This may for example be done before the column 222 arrives at a jobsite. The horizontal plates 206a, 206b of the respective top and bottom T-plate connectors 216 may be connected to the top and bottom flanges, respectively, of the beam 224 as by bolt fasteners 232 through bolt holes 214. This may be done for example at a jobsite. While bolted fasteners 230 and 232 may be preferred, it is alternatively or additionally possible to connect the vertical plates and/or horizontal plates to the beam and column by welding and/or high strength adhesives.
A shear tab 234 may be affixed to the column 222 as by welding, and to the beam as by bolt fasteners to assist in bearing gravitational and lateral loading of the moment frame 220. In certain high-load applications, it may be desirable to provide large T-plates 216 and/or bolt fasteners 230. In order to prevent interference between the vertical plates 202, 204, the bolt fasteners 230 and/or the shear tab 234, notches 236 may be formed in portions of the vertical plates 202 and 204. Further details of such notches 236 are described in U.S. patent application Ser. No. 18/481,626, entitled “Notched Moment Frame Connector System,” which application is incorporated by reference herein in its entirety. The notches 236 on one or both T-plates 216a, 216b may be omitted in further embodiments.
As noted above, unlike conventional welded structural connectors, the vertical plate 202, 204 is integrally formed with the horizontal plate 206a, 206b from a single section of a beam. Forming the vertical plate and horizontal plate from a single piece of structural steel omits the time and labor needed to form a weld, and omits the possibility of human error in forming such a weld. Additionally, as a conventional structural connector is brittle at the weld site, the one-piece integrated structural connector of the present technology is more ductile than conventional structural connectors.
In fabrication, multiple blanks 210 may be cut from a length of a beam 200. In embodiments, T-plate connectors 216 from blanks 210 taken from anywhere on a beam (or different beams) may be used as the top and bottom T-plate connectors shown in
In this regard, as noted above, when steel is heated to at least a predefined temperature, crystals in the steel can align in the same direction to give the steel a grain. It is an advantage of the present technology that the grain of the top and bottom T-plate connectors 216a, 216b may align with each other, for example when taken from the same blank. When installing the top and bottom T-plate connectors from the same blank, one of the connectors may be flipped over (relative to its original orientation in the blank 210) to ensure the grains of the top and bottom T-plates align with each other. It is also possible that T-plate connectors from different blanks on a given beam may be used and the grains of the respective T-plate connectors may align.
In embodiments described above, the horizontal plate 206 has a rectangular shape. It is understood that the horizontal plate 206 may have other shapes in further embodiments which may be efficiently cut as blanks 210 from a beam 200.
In embodiments described above, a pair of T-plate connectors are formed from a single blank. This provides efficiencies in fabricating the T-plate connectors. Additionally, there are advantages to the use of two T-plate connectors from the same blank as the top and bottom connectors in a moment frame connection, in that the T-plates connectors will have the same properties and responses to stresses as noted above. However, while the above embodiments describe cutting a pair of T-plate connectors from a single I-shaped beam, in further embodiments, a single T-plate connector may be cut from a T-shaped beam. A T-shaped beam is one having a single flange integrally formed with a web. T-plate connectors cut from adjacent sections of such a T-shaped beam may also share like properties and responses to stresses when used as the top and bottom connectors in a moment frame connection.
The foregoing detailed description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. The described embodiments were chosen in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.
