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EP0095614A1 - Connexion au cisaillement d'une construction de fermes - Google Patents

Connexion au cisaillement d'une construction de fermes Download PDF

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Publication number
EP0095614A1
EP0095614A1 EP83104603A EP83104603A EP0095614A1 EP 0095614 A1 EP0095614 A1 EP 0095614A1 EP 83104603 A EP83104603 A EP 83104603A EP 83104603 A EP83104603 A EP 83104603A EP 0095614 A1 EP0095614 A1 EP 0095614A1
Authority
EP
European Patent Office
Prior art keywords
truss
construction
truss member
chord
unsplit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP83104603A
Other languages
German (de)
English (en)
Inventor
Emanuel A. Coronis Jr.
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of EP0095614A1 publication Critical patent/EP0095614A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C3/00—Structural elongated elements designed for load-supporting
    • E04C3/38—Arched girders or portal frames
    • E04C3/40—Arched girders or portal frames of metal
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C3/00—Structural elongated elements designed for load-supporting
    • E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
    • E04C3/04—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of metal
    • E04C3/11—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of metal with non-parallel upper and lower edges, e.g. roof trusses
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C3/00—Structural elongated elements designed for load-supporting
    • E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
    • E04C3/04—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of metal
    • E04C2003/0486—Truss like structures composed of separate truss elements
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C3/00—Structural elongated elements designed for load-supporting
    • E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
    • E04C3/04—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of metal
    • E04C2003/0486—Truss like structures composed of separate truss elements
    • E04C2003/0491—Truss like structures composed of separate truss elements the truss elements being located in one single surface or in several parallel surfaces

Definitions

  • the present invention relates to a wide-span truss construction and its method of fabrication. More particularly, the present invention relates to truss constructions known as shear connection truss constructions, which are distinctive in the absence of a horizontal reaction or bending moment when disposed on vertical support members.
  • truss constructions have existed for many years, that attempt to serve for roof support in wide-span buildings. Certain of these trusses are known as rigid frame trusses, while others purport to be shear connection trusses.
  • the "shear” and “rigid” terminology refers to the nature of the connection between the lateral end of the truss and the vertical columns upon which the trusses are supported.
  • a moment connection exists between the truss and its supporting columns. This moment connection gives rise to an associated phenomenon at the base of each column which is known as horizontal reaction.
  • a horizontal reaction will occur at the bottom of a vertical column whenever the top of such column is exposed to a non-vertical or angular moment, generally known as a bending moment.
  • a horizontal reaction In the field of wide-span construction, the accepted consequence of the presence a horizontal reaction, is that unduly large, and frequently immense, concrete supports are required to buttress the base of each vertical column against the forces of the horizontal reaction.
  • One example of a prior art rigid-frame structure which utilizes some of the procedures of the method of the present invention, comprises the patent to Temple, United Kingdom Patent No. 692,312 (1953).
  • Temple illustrates the known procedures of longitudinally splitting a construction beam and of forming an angular displacement relative to the upper and lower chords of such a longitudinally split beam.
  • the ultimate result is still one of a rigid frame structure in which a moment connection exists between the vertical columns and the horizontal truss.
  • a shear connection truss construction is disclosed, that, by its particular dimensional configuration, has been found to eliminate the development of a bending moment or horizontal reaction, when the construction is disposed on vertical support columns.
  • the truss construction consists essentially of paired truss members attached to each other in end-to-end abutment, each truss member having an essentially I-shaped cross-section defined by essentially parallel, longitudinally extending flanges, and a connecting web extending transversely between the flanges.
  • Each truss member defines a unitary, unsplit end, and a longitudinally split end, the longitudinally split end defined by an upper chord, located in the same directional plane as the unsplit end, and a lower chord extending at an acute angle with respect to the upper chord, with a web that is discontinuous with the web of the unsplit end.
  • the unsplit end of the truss member has a length ranging from 15% to 35% of the total length of the member as measured from the unsplit end to the furthest tip of the upper chord.
  • the acute angle between the upper chord and the lower chord may range up to about 15° and preferably from about 5° to 15°.
  • the upper chord and the lower chord are integral with the unsplit end at a junction point, and the respective flanges on the upper and lower chord and the adjacent flanges disposed on the unsplit end are likewise integral.
  • the construction of the present invention is characterized by the absence of a bending moment at this junction point and the corresponding absence of a horizontal reaction when the construction is disposed on vertical support columns.
  • the present truss construction can be prepared in a variety of ways, including the technique of splitting an I-beam to form the upper and lower chords.
  • the present construction may be assembled from modular components such as plate steel, rather than from pre-formed I- or T-beams.
  • the geometry of the present truss construction permits a variation in the width of the upper flange with respect to the lower flange, so that the greater compressive stress exerted upon the upper chord relative to the tension exerted upon the lower chord, can be accommodated and an economy in material usage achieved.
  • the present truss construction may utilize an upper flange either greater in cross sectional area or broader in width, than the lower flange by the assembly of the construction from premeasured flat plates.
  • a still further object of the present invention is to provide a truss construction having a lower ratio of weight per unit length of span than is attainable in prior art trusses such as solid beam or built-up trusses.
  • truss construction 2 comprises paired truss members that are joined at their flaired ends, to define, as illustrated herein, the apex of a slanted roof construction.
  • an individual truss member 4 is illustrated and is seen to comprise a unitary, unsplit end 6 and a longitudinally split end, defined by an upper chord 8 and a lower chord 10.
  • Upper chord 8 extends in the same directional plane as unsplit end 6, while lower chord 10 extends at an acute angle, labeled a.
  • truss member 4 defines an essentially I-shaped cross section, defined by longitudinally extended parallel flanges, comprising upper flange 12 and lower flange 14, connected by a transversely extending web 16. Both upper flange 12 and lower flange 14 are continuous throughout the length of truss member 4, with upper flange 12 remaining linear, while lower flange 14 changes direction at the point where lower chord 10 diverges from unsplit end 6.
  • junction point 18 The point at which lower chord 10 diverges from upper chord 8 is referred to as the junction point 18.
  • brace plates such as plate 20 are mounted on both sides of the transverse split in web 16, at junction point 18, to combine in sandwich relationship to provide the desired support. Additional bracing is possible and may be provided by one or more lattice members 22 to secure chords 8 and 10 in fixed relationship to each other.
  • an end plate 24 may be affixed to the free ends of chords 8 and 10 to provide a point of attachment to either the corresponding chords from another truss member, as illustrated in FIGURE 1, or directly to a vertical support structure, in a manner not illustrated herein.
  • a prominent feature of the present invention is that the truss construction and the respective truss members do not exhibit a bending moment, and do not exert a horizontal reaction, in the instance where this construction is mounted by a shear connection,upon one or more vertical support structures.
  • the forces transmitted from the present truss construction to the vertical columns, such as columns 26 illustrated in FIGURE 1 are solely vertical in nature, and the possibility of horizontal reaction at the base of the column is eliminated.
  • the truss construction of the present invention is identified as an "indeterminate structure.”
  • the expression "indeterminate”, in the field of structural engineering, implies “that which cannot be solved by the application of the laws of statics alone”.
  • Various advance methods of structural analysis, such as energy principles can be applied to the trusses, using either manual or electronic computer calculation techniques. These techniques, however, tend to become lengthy, involved and expensive, and therefore prohibitive for day to day employment in the routine design of truss members.
  • the unitary unsplit end 6 should preferably have a length ranging from about 15% to about 35% of the total length of truss member 4, as measured from unsplit end 6 to the furthest tip of upper chord 8. In one embodiment of the invention, a preferred range of this length dimension may be from 16% to 29%, and more particularly approximately 20% of the entire length of truss member 4. In an alternate embodiment, wherein the truss member 4 is prepared by a technique of modular fabrication, the more preferred range of the length of unsplit end 6 may extend from 25% to about 33% of the length of the entire truss member 4.
  • a further aspect of the present invention is that the acute angle a defined between upper chord 8 and lower chord 10 may range up to about 15°, and preferably from about 5° to about 15°.
  • the exact value for this angle may vary, depending upon span loading and truss member selection but will generally range more particularly between 7° and 13°.
  • the slope or pitch variation between upper chord 8 and lower chord 10 may vary an average from 1-1/2" to 2-1/2" for every foot of length of the respective chords.
  • FIGURES 3-6 refer in general to a first technique for fabrication, wherein a unitary I-beam 28 is provided having a length predetermined to coincide with the desired longitudinal dimension of the truss member to be formed.
  • I-beam 28 comprises essentially parallel upper flange 12 and lower flange l4,and transversely extending web 16.
  • a longitudinal split or cut 30 is made in web 16 to alength that will correspond to the length desired for upper chord 8, shown clearly in FIGURE 5.
  • both upper chord 8 and lower chord 10 are formed by the provision of split 30, and are seen in FIGURE 5 to possess essentially T-shaped cross sections.
  • Lower chord 10 is then bent or deflected at a predetermined angle a away from upper chord 8, and paired brace plates 20 are then affixed to the adjacent surfaces of the portions of web members 16 to secure the web members to each other in a sandwich relationship.
  • a plurality of latice members 22 may be provided to give further support between upper chord 8 and lower chord 10. The exact number and positioning of the latice members 2 . 2 may vary with the load requirements of the particular construction.
  • T-beams may be brought together to form the final I-beam shape of the truss member.
  • the above sequence would be modified by the deletion of the splitting of the I-beam, as only the transverse cut 32 in one of the T-beams would be necessary.
  • one of the T-beams could be transversely cut and then bent to the predetermined angle, and subsequently the uncut T-beam could be appropriately mated therewith to form the structure shown in FIGURE 5.
  • the web members 16 could be joined at the unsplit end by a variety of known techniques, including butt welding and the like, and the invention is accordingly not limited to a specific such joining technique.
  • a further embodiment of the present invention comprises the fabrication thereof from a plurality of modular components, as illustrated herein in FIGURE 7.
  • a plurality of planar sheets of material could be individually fashioned to conform in all dimensions, including shape, to that of their respective component parts.
  • flanges 12 and 14 could be fashioned as continuous strips, with flange 14 bent appropriately to define the angular displacement of lower chord 10.
  • Web member 16 might be prepared in two sections, the first comprising an essentially L-shaped member for unsplit end 6 and upper chord 8, and a separate, approximately rectangular portion for lower chord 10. Alternately, it would be possible to fashion a continuous flat plate conforming to the ultimate shape of web 16 in the final truss member.
  • a wide variety of construction grade materials may be utilized to fashion the truss members and the truss construction of the present invention.
  • the materials useful in this regard are all well known, including the widely employed structural steels, and the like.
  • the variety of ways in which the present truss construction may be fabricated, allows a correspondingly broader variety of metals to be utilized, as one is not limited to the use of specific metals suited for the manufacture of an I-beam.
  • a further advantage conferred by the use of the modular fabrication method disclosed herein comprises the ability to vary the width of the flanges with respect to each other, to permit economies of material to be made without sacrifice in structural integrity.
  • FIGURE 8 wherein a cross section of an essentially I-shaped member is shown, embodying this differential. While this construction is eminently suited for the instance where the beam is assembled by a modular fabrication technique, it is to be understood that I - beams having variant flanges may likewise be fabricated and formed into truss members in accordance with the present invention, so that they, too, may appreciate this variation in flange size. The invention is therefore not limited to a particular mode of fabrication, but encompasses all variations of such modes within its scope.
  • the truss construction of the present invention facilitates economies and manufacture and use.
  • the elimination of bending moment and horizontal reaction as described earlier permits the present truss construction to be "simply supported".
  • the only transfer of force from the truss construction to the vertical supports is vertical in nature. This permits a far simpler and economically more practical type of support approach to wide-span truss constructions that has been heretofore possible.
  • the present truss construction may be easily bolted or otherwise secured to the load-bearing columns, as shown in FIGURE 1-Alternately, the truss construction may be rested upon a pair of masonry or concrete walls, not shown, and simply bolted vertically downward thereinto.
  • connections of the type described above are exceedingly simple and easily performed. This feature renders the present truss constructions particularly well adapted for field construction, in the instance where the sections of the truss construction are prefabricated in the contractor's plant.
  • the connections between the lateral termini of the truss construction and the vertical support members are not rigid and thus the complex body of engineering analysis that accompanies and governs all rigid-frame concepts is avoided. Accordingly, massive buttressing of vertical supports is eliminated, and a simpler "normal" foundation can be utilized herewith.
  • each truss member 4 may be provided with clips to receive wood roof purlins.
  • An advantage of the present truss construction is that the loading of the purlins on top of the upper flanges is not limited to panel points, as in the instance of the prior art. This limitation has, in the past given rise to extreme difficulty in the shipment of prior art truss constructions of all types.
  • the present truss construction permits a degree of practical flexibility in the spacing of purlins that has been unattainable in the prior art as, for example, each upper flange can be designed to receive a variety of sizes, loadings and slopes, all of which are highly valuable in the design of modern ceiling systems.
  • the present truss constructions may be utilized in a variety of applications, either together in a truss construction, or individually with variant vertical support members.
  • individual truss members may be mounted with their flaired ends adjacent a central vertical support member in cantilever fashion, utilizing such central support exclusively.
  • truss constructions can be placed on existing wall structures without the need for further support or reenforcement of those vertical load bearing structures, so that reduced expense of retrofitting the present truss construction renders building renovations less expensive and more desirable.
  • the present truss constructions can thus be seen to offer a variety of applications in the building industry.

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  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Rod-Shaped Construction Members (AREA)
EP83104603A 1982-05-10 1983-05-10 Connexion au cisaillement d'une construction de fermes Withdrawn EP0095614A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US37636682A 1982-05-10 1982-05-10
US376366 1982-05-10

Publications (1)

Publication Number Publication Date
EP0095614A1 true EP0095614A1 (fr) 1983-12-07

Family

ID=23484736

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83104603A Withdrawn EP0095614A1 (fr) 1982-05-10 1983-05-10 Connexion au cisaillement d'une construction de fermes

Country Status (5)

Country Link
EP (1) EP0095614A1 (fr)
AU (1) AU561183B2 (fr)
CA (1) CA1207974A (fr)
WO (1) WO1983004064A1 (fr)
ZA (1) ZA833332B (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2263190C1 (ru) * 2004-04-05 2005-10-27 Казанская государственная архитектурно-строительная академия КГАСА Стальная рама
US9181700B2 (en) 2007-01-26 2015-11-10 Morton Building, Inc. Tapered truss

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007104147A1 (fr) * 2006-03-13 2007-09-20 Look North Products Inc. Composant de construction de panneau et construction d'un abri
US9879414B2 (en) * 2015-05-12 2018-01-30 Power Solutions International, Inc. Three dimensional structural frames and enclosures

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR508720A (fr) * 1919-02-05 1920-10-21 George Hutchinson Nouveaux perfectionnements aux éléments de charpente pour poutres, colonnes, etc.
US1763940A (en) * 1927-10-08 1930-06-17 Bates Expanded Steel Truss Co Metal joist and the manufacture thereof
US1822331A (en) * 1928-05-07 1931-09-08 Bates Expanded Steel Corp Expanded metal joist
DE2334140A1 (de) * 1972-07-06 1974-01-24 Jun Emanuel A Coronis Verfahren zum bau eines dachgeruestes

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR508720A (fr) * 1919-02-05 1920-10-21 George Hutchinson Nouveaux perfectionnements aux éléments de charpente pour poutres, colonnes, etc.
US1763940A (en) * 1927-10-08 1930-06-17 Bates Expanded Steel Truss Co Metal joist and the manufacture thereof
US1822331A (en) * 1928-05-07 1931-09-08 Bates Expanded Steel Corp Expanded metal joist
DE2334140A1 (de) * 1972-07-06 1974-01-24 Jun Emanuel A Coronis Verfahren zum bau eines dachgeruestes

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2263190C1 (ru) * 2004-04-05 2005-10-27 Казанская государственная архитектурно-строительная академия КГАСА Стальная рама
US9181700B2 (en) 2007-01-26 2015-11-10 Morton Building, Inc. Tapered truss
US9689163B2 (en) 2007-01-26 2017-06-27 Morton Building, Inc. Tapered truss

Also Published As

Publication number Publication date
CA1207974A (fr) 1986-07-22
AU1601383A (en) 1983-12-02
WO1983004064A1 (fr) 1983-11-24
AU561183B2 (en) 1987-04-30
ZA833332B (en) 1984-01-25

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