AU2017254962B2

AU2017254962B2 - A Stud

Info

Publication number: AU2017254962B2
Application number: AU2017254962A
Authority: AU
Inventors: Paul Jones; Dennis Sutton
Original assignee: BlueScope Steel Ltd
Current assignee: BlueScope Steel Ltd
Priority date: 2012-12-07
Filing date: 2017-11-03
Publication date: 2019-07-11
Anticipated expiration: 2033-04-10
Also published as: AU2017254962A1; AU2016222426A1

Abstract

A stud for use in the construction of steel frames for buildings is disclosed. The stud 7 includes a tab 13 5 (which may be described as a tongue or an extension) at one end that forms a bracket that can facilitate bolting the stud to other framework members or an underlying support structure, thereby allowing load transfer through the stud. 9654832_1 (GHMatters) P92094.AU.3 3/11/17

Description

A STUD

The present invention relates to a stud for use in the construction of steel frames for buildings.

The present invention also relates to steel frames for buildings that are constructed using the stud of the invention as a component of the frames.

The present invention also relates to a method of manufacturing the stud of the invention.

A steel frame for a building has to transfer uplift and downwards loads from the top of the frame to the bottom of the frame. The key load is uplift load. Uplift load is usually generated by wind uplift but could also be generated by horizontal racking forces which are 15 transferred through the bracing of the frame. Different levels of uplift load need to be resisted in different parts of the frame, with higher levels of resistance required at the ends of bracing and openings, such as doors and windows, where loads are concentrated.

Typically, steel frames are held onto an underlying support structure, such as a concrete floor slab, by tie-down brackets. There are a number of different types of tie-down brackets on the market in Australia, including C-shaped brackets, L-shaped brackets, 25 and fixing straps bracing to the side of the floor slab.

In any given situation, the selection of a tie-down bracket depends on a range of factors including but not limited to the amount of uplift force being transferred through the tie-down brackets. In turn, the amount of 30 uplift force depends on factors such as where the tie-down brackets are placed in a wall and the amount of load being applied - usually wind or seismic load. Typically, tiedown brackets with higher capacities are required where there are higher wind or seismic loads, larger openings in 35 the frame, or less bracing in the frame.

The above description is not an admission of the common general knowledge in Australia or elsewhere.

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The invention replaces the current need to use tie-down brackets in steel frames, including in higher load situations .

The invention makes it possible to provide a comparable or stronger tie down of a steel frame to an underlying structure than that provided by known tie-down brackets .

The invention makes it possible to achieve cost savings in the tie-down bracket, fasteners and labour to install the bracket. The invention also makes it possible to achieve consistent higher quality steel frame construction.

In broad terms, the present invention provides a stud for use in the construction of steel frames for buildings that includes a tab (which may be described as a tongue or an extension) at one end that forms a bracket that can facilitate bolting the stud to other framework members or an underlying support structure, thereby allowing load transfer through the stud.

The present invention provides a stud for use as a steel framework member, the stud including a tab at one end that forms a bracket that can facilitate securing the stud to another framework member in the form of a C-shaped lower plate that defines a channel for receiving and retaining the stud without the use of tie-down brackets, thereby allowing load transfer through the stud, the stud including a central web and two flanges extending from opposite side edges of the central web, the tab being an extension of the central web at one end of the central web and extending perpendicular to a plane of the central web, and the tab including one or more holes through which fasteners, such as bolts, may be located to secure the tab and thereby the stud to the C-shaped lower plate when the stud is positioned in the channel without the use of tie35 down brackets.

It can readily be appreciated that the flanges of the above-described stud do not extend in a longitudinal

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2017254962 21 Jun 2019 direction of the stud beyond the tab.

The stud may be C-shaped in a transverse section with the central web and two flanges extending from opposite side edges of the central web and two inturned lips extending from the edges of the flanges.

The width of the tab may be selected to be similar to, typically marginally less than, the width of the channel in the C-shaped lower plate.

The stud may include the tab at both ends of the stud.

The stud may be made from steel.

The stud may be roll-formed from steel sheet or strip.

More particularly, the stud may be roll-formed from relatively light gauge steel sheet or strip, for example less than 1.6 mm thick.

The present invention also provides a steel frame for a building that includes a plurality of the abovedescribed studs bolted or otherwise fastened to other framework members or to a C-shaped lower plate that defines a channel that receives lower ends of the studs and are retained in the channel without the use of tiedown brackets, thereby allowing load transfer through the studs .

The present invention also provides a method of manufacturing the above-described stud that includes (a) removing rectangular-shaped sections along both sides of a steel sheet or strip at one end of the sheet or strip so that the remaining section of the sheet or strip at the end defines a tab that is narrower than an adjacent section of the sheet or strip from which the tab extends, (b) roll forming the adjacent section of the sheet or strip and forming a central web and two flanges extending from opposite side edges of the central web, with the tab extending from an end of the central web as an extension of the central web, and (c) bending the tab out of a plane of the central web so that it extends perpendicular to the

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2017254962 21 Jun 2019 plane of the central web and forms a bracket that can facilitate bolting or otherwise fastening the stud to other framework members or to an underlying support structure.

The method may include removing the rectangularshaped sections by notching the sheet or strip.

The method may include punching or otherwise forming one or more holes through which fasteners, such as bolts, may be located to secure the tab and thereby the 10 stud to the other framework members or the underlying support structure. This step may be carried out before or after roll forming step (b).

Bending step (c) may be a manual step.

The method may include roll forming the adjacent 15 section of the sheet or strip and forming a C-shape in a transverse section with the central web and two flanges extending from opposite side edges of the central web and two inturned lips extending from the edges of the flanges.

The present invention is described further by way of example only with reference to the accompanying drawings , of which:

Figure 1 is a perspective view of one embodiment of a stud in accordance with the invention;

Figure 2 is a diagrammatic side elevation of a section of an embodiment of a steel frame for a wall of a building in accordance with the invention that includes a plurality of the stud shown in Figure 1;

Figure 3 is a side view of the stud shown in Figure 1 mounted to a concrete floor slab;

Figure 4 is a perspective view of a lower section of the stud shown in Figure 1 mounted to a lower plate of a steel frame for a wall, with the tab of the stud removed to simplify the Figure;

Figure 5 is a perspective view of the lower section of the stud shown in Figure 1 before the tab is folded from an rolled-formed arrangement to form the stud; and

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Figure 6 is a front view of the arrangement shown in Figure 5.

With reference to Figure 2, the embodiment of a steel frame 3 for a wall 5 of a building, such as a domestic house, shown in the Figure includes an assembly of a lower plate 3 that is mounted to an underlying support structure, such as a concrete floor slab (not shown in Figure 2), an upper plate 5, a plurality of vertical wall studs 7 in accordance with one embodiment of the invention, and strap bracing 9.

The lower and upper plates 3, 5 may be any suitable profile. Typically, the lower and upper plates 3, 5 are C-shaped in a transverse section with a central web and two flanges extending from opposite side edges of 15 the web.

The strap bracing may be any suitable profile.

The embodiment of the stud 7 in accordance with the invention shown in the Figures is roll-formed from light gauge steel sheet or strip and is C-shaped in a transverse section with:

(a) a central web 17, (b) two flanges 19 extending from opposite side edges of the central web 17, (c) two inturned lips 25 extending from the edges of the flanges 19, and (d) a tab 13 with two pre-punched holes 15 extending from the central web 17 at one end of the stud 7 perpendicularly to the central web.

The tab 13 forms a bracket at the lower end of the stud 7 that facilitates bolting or otherwise fastening the stud 7 to the lower plate 3 and to an underlying support structure, such as a concrete floor slab (not shown in Figure 2), thereby allowing load transfer through the stud 7.

More particularly, the stud 7 is formed so that the stud 7 can be positioned to extend vertically from the lower plate 3 with a lower end of the stud 7 positioned

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2017254962 21 Jun 2019 within a channel defined by the lower plate 3, with the tab 13 seated on and contacting the central web of the lower plate 3 and bolted or otherwise fastened to the lower plate 3 via fasteners (not shown) extending through 5 the holes 15 in the tab 13 into the underlying structure.

Typically, washers 27 (see Figure 3) are used to provide more effective engagement of the fasteners across the surface of the tab 13.

The stud 7 may be any suitable length, width and 10 depth dimensions. A range of different length studs 7 are shown in the Figures.

The positions of the studs 7 and the bracing 9 are determined by reference to appropriate building codes and having regard to requirements for openings, such as doorway openings 11 and window openings (not shown in Figure 2).

The applicant has carried out test work in relation to the stud of the invention shown by way of example in the Figures and two known brackets for mounting studs to other framework members or underlying support structures .

The purpose of the test work was to determine the loads required to pull-out the brackets and the stud from an underlying structure, i.e. the tie-down capacities of the brackets and the studs.

The results of the test work are set out in the following table.

Tie down type	Known anchor bolt & washer	Known Lshaped bracket, with anchor bolt any gauge	Stud of the invention, with anchor bolt
Design capacity	6.25kN (0.75mm)	16.3kN (0.75mm)	15.29kN (0.75mm) 21.53kN (1.0mm)

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30.37kN (1.2mm)

The table shows that, while the tie-down capacity of the stud of the invention is slightly lower in 0.75mm thick material (lkN - 6% lower) than that of the known L5 shaped bracket, the capacity is significantly higher in 1.0mm, 1.2mm and thicker material.

The invention was made by the applicant during the course of considering whether there are viable alternatives to tie-down brackets currently on the market 10 in Australia for cyclonic regions. The applicant tested the stud of the invention without any real expectations about the performance of the stud. The applicant was surprised by the performance of the stud of the invention and the finding that the stud is a viable alternative to 15 the known tie-down brackets.

The stud of the invention may be roll-formed from light gauge steel sheet or strip with the tab an integral part of the stud.

The roll former operation includes:

(a) removing, for example by notching, rectangularshaped sections (not shown) along both sides of a steel sheet or strip at one end of the sheet or strip so that the remaining section of the sheet or strip at the end defines a tab 13 that is narrower than an adjacent section of the sheet or strip from which the tab extends, (b) punching or otherwise forming the holes 15 in the tab 13, and (c) roll forming the adjacent section of the sheet or strip and forming (i) the central web 17, (ii) the two flanges 19 extending from opposite side edges of the central web, and (iii) the two inturned lips 25, with the tab 13 extending from an end of the central web 17 as an extension of the web 17 in the plane of the web 17.

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This partly-formed stud 7 is shown in Figures 5 and 6.

A final step of the method involves bending the tab 13 out of a plane of the central web 17 so that it extends perpendicularly to the plane of the central web and forms a bracket that can facilitate bolting or otherwise fastening the stud to other framework members or to an underlying support structure.

It can be appreciated from the above that the steel frame of the invention does not require any additional brackets to be fastened to the stud 7 to install the stud 7 into the steel frame. The above test work shows that the stud 7 is can give a connection which is comparable in terms of strength to using a bracket but 15 eliminates the cost of the bracket, the fasteners to attach the bracket, and the labour required to attach the bracket.

Many modifications may be made to the embodiments of the invention described above without departing from 20 the spirit and scope of the invention.

By way of example, the invention is not confined to mounting studs to an underlying structure or to other framework members. The stud may be used in other applications. By way of example, a further opportunity is 25 to use the stud at the top of walls in cyclonic conditions so trusses can be tied directly to studs. This provides direct connection between trusses and studs and provides very good tie down capacity for wall frames in high wind areas .

In addition, whilst the embodiment of the stud 7 shown in the Figures includes two holes 15 in the tab 13, it can readily be appreciated that the invention is not so limited and extends to any suitable number of holes 15.

In addition, whilst the embodiment of the stud 7 35 shown in the Figures includes a tab 13 at one end only, it can readily be appreciated that the invention is not so limited and extends to studs 7 have tabs 13 at both ends.

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1.

A steel stud for use as a steel framework

2017254962 21 Jun 2019

Claims

member, the stud including a tab at one end that forms a

5 bracket that can facilitate securing the stud to another framework member in the form of a C-shaped lower plate that defines a channel for receiving and retaining the stud without the use of tie-down brackets, thereby allowing load transfer through the stud, the stud

10 including a central web and two flanges extending from opposite side edges of the central web, the flanges not extending in a longitudinal direction of the stud beyond the tab, the tab being an extension of the central web at one end of the central web and extending perpendicular to 15 a plane of the central web, and the tab including one or more holes through which fasteners may be located to secure the tab and thereby the stud to the C-shaped lower plate when the stud is positioned in the channel without the use of tie-down brackets.

20
2. The stud defined in claim 1 wherein the tab extends perpendicular to a longitudinal axis of the stud.
3. The stud defined in claim 1 or claim 2 being Cshaped in a transverse section with a central web and two flanges extending from opposite side edges of the central

25 web and two inturned lips extending from the edges of the flanges .
4. The stud defined in any one of the preceding claims includes the tab at both ends of the central web.
5. The stud defined in any one of the preceding

30 claims being a roll-formed stud.
6. A steel frame for a building that includes a plurality of the studs defined in any one of the preceding claims bolted or otherwise fastened to a C-shaped lower plate that defines a channel that receives lower ends of

35 the studs and are retained in the channel without the use of tie-down brackets, thereby allowing load transfer through the studs.

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7. A building that includes the steel frame defined in claim 6.
8. A method of manufacturing the stud defined in any one of claims 1 to 6 that includes (a) removing

5 rectangular-shaped sections along both sides of a steel sheet or strip at one end of the sheet or strip so that the remaining section of the sheet or strip at the end defines a tab that is narrower than an adjacent section of the sheet or strip from which the tab extends, (b) roll
10 forming the adjacent section of the sheet or strip and forming a central web and two flanges extending from opposite side edges of the central web, with the tab extending from an end of the central web as an extension of the central web, and (c) bending the tab out of a plane

15 of the central web so that it extends perpendicular to the plane of the central web and forms a bracket that can facilitate bolting or otherwise fastening the stud to other framework members or to an underlying support structure.

20 9. The method defined in claim 8 includes removing the rectangular-shaped sections by notching the sheet or strip.

10. The method defined in claim 8 or claim 9 includes punching or otherwise forming one or more holes through

25 which fasteners may be located to secure the tab and thereby the stud to the other framework members or the underlying support structure.
11. The method defined in any one of claims 8 to 10 includes roll forming the adjacent section of the sheet or

30 strip and forming a C-shape in a transverse section with the central web and two flanges extending from opposite side edges of the central web and two inturned lips extending from the edges of the flanges.