AU724737B2

AU724737B2 - Fabricated structural members

Info

Publication number: AU724737B2
Application number: AU48505/97A
Authority: AU
Inventors: Dimitrios TRAMBAS
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-12-19
Filing date: 1997-12-19
Publication date: 2000-09-28
Anticipated expiration: 2017-12-19
Also published as: AU4850597A

Description

P/00/01i1 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT

C,

0 *0 *00* .00* ~0 *0 0 *0 0 0* The following statement is a full description of this invention, 00000 0 Invention Title: FABRICATED STRUCTURAL MEMBERS Applicant: DIM ITRIOS TRAMBAS including the best method of performing it known to me: C:\WINWORD\JENNY\WORK\P04267A.DOC 2 FABRICATED STRUCTURAL MEMBERS This invention relates generally to structural members; and more particularly to a method of fabricating structural members, such as beams, columns and the like, from two or more components, and to structural members so fabricated.

The invention has particular application to the production of relatively light-weight metallic structural members such as steel universal beams, universal columns, T-sections and hollow flange I-beams, and is herein described in this context. It will be appreciated, however, that the invention is not limited to this particular application but that it may also be used in producing more heavy-weight structural sections.

go fabrication of structural steel beams typically involves welding strip- *.like plate elements along seam joints utilising, for example, corner welds, tee welds and butt welds. This process is generally time consuming and requires high precision in the formation of the weld joints. In addition, this fabrication process does not readily lend itself to continuous production.

It would be desirable to provide a new method of fabricating structural o members which is relatively simple and fast and which would be suitable for Sa 20 continuous production.

~According to a broad aspect, the present invention provides a method of fabricating a structural member from two or more metal components, including the steps of: heating a first metal component and a second metal component to a fusion temperature; positioning the first and second components adjacent each other; and pressing the adjacent Components together during and/or after heating such that they weld or fuse in a region thereof into a unitary element and such that a dimension of the fused region is less than the combination of the corresponding dimensions of the separate components prior to pressing.

In another broad aspect, the present invention provides a structural member fabricated in accordance with the above method.

C:\WINWORD\JENNY\SPECI\P4267.DOC While certainly contemplated by the invention, it is not essential that the whole of the first component and the whole of the second component be heated to the fusion temperature. Only those portions of the components which are to be pressed together to form the welded or fused region need be heated to the appropriate temperature.

In a preferred form of this invention the first component includes a substantially flat portion and the second component includes a substantially flat portion. The respective flat portions are positioned adjacent each other in opposed face-to-face relation and, during and/or after heating, the flat portions are pressed. together to form the fused region. After the pressing step, a thickness dimension of the fused region is less than the combination of corresponding material thicknesses for the separate component flat portions prior to pressing.

*.In a preferred embodiment of the invention, the step of pressing the 15 adjacent first and second components together includes rolling. Furthermore, the pressing step may include a series of successive rolling operations and additional heating of the first and second components may optionally be included between those successive rolling operations.

S-Preferably, heat is induced to each of the metal components by high oe 20 frequency, high voltage and low amp electric current. As an alternative, however, the heat may be generated by burning a fuel such as gas, coal or oil.

Plasma heating or laser heating may also optionally be used.

Typically, either or both of the first and second metal components will include at least one portion which does not become fused to the respective other component. Any such non-fused portion may undergo a deformation operation to achieve the final configuration of the fabricated structural member.

For example, the non-fused portion(s) may be roll-formed into a desired configuration. This additional deformation of a non-fused portion of either or both of the first and second components may take place before and/or during and/or after the heating and pressing steps described above.

In a preferred embodiment of the invention the components from which the structural member is ultimately fabricated comprise strip-like metal material.

C:\WINWORD\JENNY\SPECI\P4267.DOC This material may be plastically deformed to a particular sectional shape prior to the heating and pressing steps which fuse the components together as described. For example, the basic strip material may be pre-rolled to form channel section components, L-section components or even pipes or tubes.

According to a particularly preferred embodiment the method of the invention is carried out as a continuous process. For example, two separate metal strips constituting the first component and the second component may be fed from reels of stock strip material along the process path. The separate strips are substantially flat and are aligned and positioned adjacent each other one above the other in opposed face-to-face relation as they travel along the process path. The first and second strip components are induction heated to fusion temperature before passing between a series of rollers which press a .:.":region of the strips together to fuse or meld the two components in that region S"into a unitary element. The strip components may be heated simultaneously in a single heating operation. Alternatively, they may be heated separately before being brought together into the adjacent and opposed relation for pressing.

After pressing, the now unified first and second strip components may proceed along the continuous process path to additional rollers at which o• S-portions of the strip components which were not fused together can be 20 deformed to take up the final configuration of the desired structural member.

:o Alternatively, the unified strip components can be re-coiled onto a stock reel to be further processed at a later time.

As a variation on the above process the stock metal strip material which constitutes the first and second components may undergo a preliminary forming process (again, preferably continuous) through a series of rollers to produce a first component and a second component having other than the simple flat cross-section of the stock strip material. That is, the strip may be preliminarily roll-formed into, for example, a channel section or an L-section. Particular portions of the first component and second component so formed may be substantially flat. Such flat portions of the first and second components may then be heated and brought together and pressed in a continuous fashion as described above to form beams or other structural members having various C:\WINWORD\JENNY\SPECI\PO4267.DOC final cross-sections.

In another particularly preferred embodiment, the method of the invention is carried out with a pipe or tubular member. The method may commence with a preliminary roll-forming operation in which substantially flat, sheet-like metal strip or plate material is roll-formed into a pipe or tube of circular cross-section. The pipe is then squashed across that section so that opposite side walls of the pipe are deformed towards each other. In this particular embodiment of the invention these opposite side walls of the pipe constitute the first component and the second component to be heated and pressed. The pipe is heated to a fusion temperature of the particular metal used and the opposite side walls of the pipe which have been squashed into proximity are pressed together so that the opposite side walls in the central region of the section fuse into a unitary element and expand laterally as the pressing reduces the thickness of the fused section. The laterally outermost 15 regions of the pipe section remain hollow producing a characteristic "dog-bone" shape. These non-fused laterally outer portions may then undergo further rolling to provide the desired formation at the extremities of the beam section.

For example, these hollow regions may be further roll-formed to provide hollow flange members at either end of the fused region which the central web of the 20 beam section.

One of the benefits of the method of this invention is that the fused region can be selected as the central web portion of the beam or column fabricated, and the thickness of the web can be varied in the pressing step.

Since the web has a relatively minor load-bearing roll compared with flange members at the extremities of the web, the web thickness can be readily minimised during the pressing step. As the web thickness is minimised the extreme portions of the section, being the non-fused portions, are displaced outwardly from the neutral axis of the structural member. This method therefore provides a very flexible process for fabricating beams and other structural members.

Preferably, the method of this invention is carried out using a first component and a second component formed of steel, and the fusion C:\WINWORD\JENNY\SPECI\PO4267.DOC 6 temperature to which the steel components is heated before and/or during pressing is typically in excess of 12000C. For example, 12800C may be a suitable fusion temperature. Depending upon the type of steel used, however, the fusion temperature may be as high as 15000C. The present invention also, of course, contemplates the use of metals other than steel.

From the foregoing it will be apparent that, according to another aspect, the present invention also provides a structural member such as a beam or a column formed according to the method previously described.

For a better understanding of the present invention preferred embodiments of the invention are hereafter described by way of illustrative example with reference to the accompanying drawings, in which like reference characters designate like features and in which: Fig. 1 is a sectional end view of two strip metal components being **formed into a structural member according to the method of the present invention; Fig. 2 is another sectional end view of the components of Fig. 1 S-undergoing further processing; Fig. 3 is a sectional end view of two channel section components to be combined according to the method of the present invention; Fig. 4 is a sectional end view of an I-beam formed from the channel section components of Fig. 3; I Fig. 5 is a sectional end view of a hollow flange I-beam formed according to the method of the present invention; Fig. 6 is a T-shaped lintel formed according to the method of the present invention from two L-section components.

Referring to Fig. 1 of the drawings, a first metal component 1 comprising stock steel strip and a second metal component 2 comprising stock steel strip are fed along a process path. The steel strip is substantially flat and is fed along the process path such that the first and second components 1,2 are in alignment and adjacent each other one above the other in opposed face-to-face relation. Each of the components 1,2 are heated to approximately 13000C by induction heating with an electric current, preferably high frequency, high C:\WINWORD\JENNYSPECI\P4267.DOC voltage and low amperage electric current. After the strip components 1,2 have reached the desired temperature and are positioned adjacent each other, they are pressed together with rollers 3 such that the components weld or fuse in a region 4 thereof into a unitary element 5. Furthermore, the pressing performed by the rollers is such that the thickness dimension 6 of the fused region 4 is less than the combination of thicknesses 7 of the separate components 1,2 prior to the pressing step. Indeed the fused region 4 may be only half the combined thicknesses of the separate components prior to pressing.

As shown in Fig. 1, each of the first and second components 1,2 include non-fused portions 8 located laterally of the central fused region 4. Either .*directly after or at some later stage, the basic section in Fig. 1 may undergo further processing toward a final section shape for the structural member. The non-fused portions 8 may undergo a deformation process by roll-forming with supplementary rollers 9, while rollers 3 may further work the fused region 4 as shown in Fig. 2. Thus, with the present invention it is possible to fabricate an elongate structural member such as a beam or column on a continuous basis and with a significant level of flexibility to vary the section dimensions. In particular, the length and thickness of a section web, typically corresponding to S" the fused region 4, can be readily varied relative to laterally extreme portions of the section. A wide variety of flange configurations can also be produced.

An alternative embodiment of the invention is illustrated in Fig. 3 and Fig.

4 of the drawings in which the first component 1 and second component 2 comprise pre-formed channel sections. These channel sections may be rollformed from a substantially flat strip of stock material as a preliminary step of the invention. Each of the first and second channel section components 1,2 include a substantially flat portion 10 and are positioned such that the respective flat portions 10 are adjacent and in opposed face-to-face relation.

The first and second channel section components are heated, at least in the region of the flat portions 10, to a fusion temperature at approximately 13000C.

During and/or after heating, and after having been positioned adjacent each other as illustrated in Fig. 3, the respective flat portions 10 of the adjacent components are pressed together, again using rollers, such that the opposed C:\WINWORD\JENNY\SPECI\P04267.DOC flat portions weld or fuse into a unitary element 5. In fusing the adjacent flat portions 10 into a unitary element, the rollers form a fused region 4 which is of narrower width 6 than the combination of thicknesses 7 of the separate components prior to pressing. In doing so, the lateral extent of the fused region 4 increases making the distance 11 between extreme fibers of the structural member section and a neutral axis 12 of the section greater.

The sides 13 of each of the channel section components 1,2 constitute non-fused portions 8 and combine to form flange elements 14 at laterally opposite ends of the central fused region 4. These non-fused flange elements 14 may optionally undergo further processing if an other than simple straight :flange configuration is required. For example, the flange elements may -°-undergo rolling after the heating and pressing operations to form the hollow flange elements 15 illustrated in Fig. Alternatively, the sectional shape shown in Fig. 5 may be fabricated from a pipe or tube element which has been squashed centrally of its preferably circular cross section such that opposite side walls of the pipe section which have been compressed into proximity are fused together according to the method of the present invention. The first and second side wall components 9 Sare heated and pressed such that the thickness dimension 6 of the fused region .999999 4 reduces to a value significantly below the combination 7 of the separate wall thicknesses of the initially proximate squashed sides of the pipe section. In so reducing the width of the fused region 4, the hollow non-fused portions at laterally opposite sides of the fused region are displaced laterally outwards from the neutral axis 12 of the section. These hollow portions may then undergo further processing, such as by rolling, and may be deformed to the hollow flange configuration 15 illustrated in Fig. Fig. 6 of the drawings shows an inverted T-shaped structural member section which may result from heating and pressing of two L-shaped sections initially positioned such that the substantially flat portion of the upright of each L-shaped section is in opposed face-to-face abutting relation with the other.

The horizontal members of the L-shaped sections in this case constitute nonfused portions 8 which combine to form the flange element 16. Alternatively, C:\WINWORDJENNY\SPECI\PO4267.DOC the section of Fig. 6 may be formed by heating, positioning and pressing substantially flat strip material over approximately half the sectional length thereof with the remaining half sectional length being non-fused and subsequently roll formed to provide the flange element 16.

It is understood that various modifications, alterations and/or addition may be introduced into the construction and arrangement of the parts specifically described and illustrated herein without departing from the spirit and ambit of the invention.

S* e* C:\WINWORD\JENNY\SPECI\P4267.DOC

Claims

1. A method of fabricating a structural member from two or more metal components, including the steps of: heating a first metal component and a second metal component to a fusion temperature; positioning the first and second components adjacent each other; and pressing the adjacent components together during and/or after the heating step such that they weld or fuse in a region thereof into a unitary element and such that one dimension of the fused region is smaller than the combination of corresponding dimensions of the components prior to pressing.

2. A method as claimed in claim 1 wherein the thickness dimension of the S-fused region is smaller than the combination of corresponding thickness dimensions for the first and second components prior to pressing.

3. A method as claimed in claim 1 or claim 2 wherein the first component includes a substantially flat portion and the second component includes a substantially flat portion, the respective flat portions being positioned adjacent each other in opposed face-to-face relation and, during and/or after heating, the flat portions being pressed together to form the fused region. S

4. A method as claimed in any one of the preceding claims wherein the step of pressing the adjacent first and second components together includes rolling.

5. A method as claimed in claim 4 wherein the pressing step includes a plurality of successive rolling operations.

6. A method as claimed in claim 5 including heating of the first and second components between the successive rolling operations.

7. A method as claimed in any one of the preceding claims wherein one or both of the first and second metal components include(s) at least one portion which is not fused to the respective other component.

8. A method as claimed in claim 7 further including the step of deforming said non-fused portion(s) before and/or during and/or after the heating and pressing steps. C:\WINWORD\JENNY\SPECI\PO4267.DOC 'I V 11

9. A method as claimed in claim 8 wherein deforming the non-fused portion(s) includes at least one roll-forming operation.

A method as claimed in any one of the preceding claims wherein the first and second components comprise separate strip-like members.

11. A method as claimed in any one of claims 1 to 9 wherein the first component and the second component are parts of a single member.

12. A method as claimed in claim 11 wherein the single member is a tube and the firstand second components include opposite side walls of the tube and wherein the step of positioning the first and second components adjacent each other includes squashing or compressing the tube transverse a longitudinal axis of the tube such that the opposite side walls are deformed towards each other.

13. A method as claimed in any one of the preceding claims wherein the first and second components are comprised of steel and the fusion temperature is in excess of 12000C.

14. A method as claimed in any one of the preceding claims wherein the heating is achieved by means of any one of, or any combination of: high frequency, high voltage and low amperage electric current; fossil fuel o* combustion; plasma heating; and laser heating. 20

15. A method as claimed in any one of the preceding claims wherein the method is carried out as a continuous process.

16. A method of fabricating a structural member substantially as herein described with reference to the accompanying drawings.

17. A structural member fabricated according to a method as claimed in any one of the preceding claims. DATED: 19 December, 1997 PHILLIPS ORMONDE FITZPATRICK Attorneys for: DIMITRIOS TRAMBAS C:\WINWORD\JENNY\SPECI\P4267.DOC