EP0079761A1 - Poutrelle I pleine - Google Patents

Poutrelle I pleine Download PDF

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Publication number
EP0079761A1
EP0079761A1 EP19820306003 EP82306003A EP0079761A1 EP 0079761 A1 EP0079761 A1 EP 0079761A1 EP 19820306003 EP19820306003 EP 19820306003 EP 82306003 A EP82306003 A EP 82306003A EP 0079761 A1 EP0079761 A1 EP 0079761A1
Authority
EP
European Patent Office
Prior art keywords
girder
web
wood
plies
ply
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.)
Granted
Application number
EP19820306003
Other languages
German (de)
English (en)
Other versions
EP0079761B1 (fr
Inventor
Matti Kairi
Markku Lehtonen
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.)
Metsaliiton Teollisuus Oy
Original Assignee
Metsaliiton Teollisuus Oy
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Filing date
Publication date
Application filed by Metsaliiton Teollisuus Oy filed Critical Metsaliiton Teollisuus Oy
Publication of EP0079761A1 publication Critical patent/EP0079761A1/fr
Application granted granted Critical
Publication of EP0079761B1 publication Critical patent/EP0079761B1/fr
Expired 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
    • E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
    • E04C3/12—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members
    • E04C3/14—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces of wood, e.g. with reinforcements, with tensioning members with substantially solid, i.e. unapertured, web

Definitions

  • the invention relates to a sturdy I-girder.
  • Sturdy timber girders are currently manufactured by gluing laminae of sawn timber together, and the product is called laminated wood.
  • the strength/weight ratio of laminated wood is rather advantageous. However, it is characterized in that the strength property which determines the dimensioning in different load situations varies, whereupon the timber girder in question is overdimensioned as regards other properties.
  • bending flexure which is in general approximately girder span/200-300, e.g. 50 mm for a span of 15 m.
  • the second one is the bending stress produced by the load in the girder. It is at its greatest in the middle of the span in the case of a single-span girder. A certain theoretical bending stress, characteristic of the material, must not be exceeded, since otherwise there is the risk that the girder breaks in the middle.
  • the third factor is the shearing stress produced by the load in the girder; the ends of the girder are subjected to shearing stress by the supports. With great loads, the shearing force tends to split a laminated-wood girder at its ends in the longitudinal direction in such a way that the lower edge of the girder is stretched because of the bending flexure and the upper surface resists this displacement, whereupon the girder splits at its ends on the horizontal level along the center line.
  • the dimensioning factor is bending flexure (span 1 in Figure 1).
  • the dimensioning factor is bending stress (span 2, Figure 1), and in the opposite extreme, in which the load is great and the span is short, the dimensioning factor is shearing stress (span 3 in Figure 1).
  • laminated wood is overdimensioned in other respects.
  • laminated wood has been glued also in the form of an I-profile ( Figure 3).
  • Bending flexure and bending stress can in this way be optimized so that there is no overdimensioning with respect to either one of these factors; which results in a considerable saving in raw material.
  • this cannot be realized except in certain special situations, since shearing stress will, when the load increases, dimension the narrowed web in such a way that it should be widened.
  • sufficient benefit cannot be drawn from this profile so as to make its manufacture economically sensible. Therefore such laminated wood is currently not manufactured to a significant degree.
  • Multi-ply wood is a prior known product, in which there is first manufactured from plies over 2 mm thick, by weatherproof gluing, a 25-75 mm thick and up to 2 meters wide, continuous, up to 30 m long sheet. The grain of most of the plies is longitudinally oriented. Laminated-wood girders, planks or various small profiles are obtained by cutting the sheet. The product has been on the market since the beginning of 1978.
  • Multi-ply wood has an advantage in being usable for many distinctly different purposes, since it has been possible to vary its structure within a wide range, when necessary. For this reason, the sturdy I-girder was consciously developed through the optimization of multi-ply wood.
  • the objective set was a sturdy, continuous and fire- resistant girder in which bending flexure, bending stress and shearing stress would all be equal dimensioning factors, whereby a maximal saving of material would be achieved. Surprisingly, this objective was achieved when the solution according to the characteristics of the accompanying claim was invented, by applying multi-ply wood.
  • I-girders having a minimum web of 65 mm are prescribed for use in public areas in Finland.
  • the fire resistance of an I-girder according to the invention is at minimum 1/2 hour.
  • long spans can be achieved in such a way that the cross section is clearly smaller than that of a laminated-wood girder dimensioned for the corresponding span.
  • a table of comparison is enclosed. The table shows the maximum spans for a multi-ply I-girder and corresponding laminated wood, when the effects of the three main dimensioning factors, bending stress, shearing stress and bending flexure, have been taken into consideration separately.
  • the maximum final span of the girder is the minimum of these three span values.
  • Figure 1 depicts graphically different load cases of laminated wood
  • Figure 2 depicts graphically a comparison of the strength properties of a laminated wood girder and a multi-ply I-girder.
  • Figure 3 depicts a known I-girder made of laminated wood
  • Figure 4 a known I-girder and a box girder made from plywood.
  • Figure 5 depicts a multi-ply I-girder according to the invention
  • Figure 6 a special application of an I-girder according to the invention.
  • Figure 1 shows graphically, with the span L of the girder as the vertical axis and the load F as the horizontal axis, the effect of bending flexure lw, bending stress 1 b and shearing stress 1 v on the dimensioning of ordinary laminated wood.
  • the proportions are presented arbitrarily, and so bending stress does not necessarily have the sector width of the type plotted.
  • Bending flexure is the dimensioning factor within span 1, bending stress within span 2, and shearing stress within span 3.
  • Figure 2 depicts graphically the cross-sectional area of laminated wood L (dotted lines) and corresponding multi-ply I-girders K (solid lines) as functions of the product which is obtained by multiplying by each other the maximum span values for bending and shearing strengths and bending flexure.
  • the spacings of the supports are 4.8, 6.0 and 7.2 m (cf. the table).
  • Three spans have been taken for each spacing, and both a laminated-wood girder and a multi-ply I-girder have been optimized for each span, and so the differences indicate that a certain strength property of laminated timber has overcapacity.
  • Figure 3 shows a known laminated-wood girder made in the shape of an I-profile, having a web u and booms p.
  • Figure 4A depicts a known I-girder, in which the web u is made of plywood and fitted between wide booms p.
  • Figure 4B for its part shows an also known box-structured plywood girder.
  • Figure 5 depicts one example of the dimensioning of a girder according to the invention.
  • Figure 6 shows how an I-girder according to the invention can be used as a pillar and be joined in a simple manner to a horizontal girder in such a way that the booms p p of the pillar continue beyond the pillar web u p to the extent of the height of the web u of the horizontal girder, and the web u of the horizontal girder for its part continues beyond the booms p of the horizontal girder to the extent of the height of the pillar web u .
  • the girder comprises a web u and a total of four booms p, which have been glued to the edges of the web on both sides of the web.
  • the booms also consist of multi-ply wood, and their grain orientation is always in the longitudinal direction of the web, in addition to which the grains of most of the different plies of the web are in the longitudinal direction of the web.
  • One conventional arrangement is such that the web is assembled from a great number of plies, for example 26 plies one on top of the other, the second, fourth and tenth ply, calculated from each surface of the web, having a transverse grain orientation.
  • an arrangement symmetrical in relation to the center plane is generally used, and the installation of transverse-grain plies on the surface is avoided so that they would not be destroyed first in a fire.

Landscapes

  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Rod-Shaped Construction Members (AREA)
EP19820306003 1981-11-18 1982-11-11 Poutrelle I pleine Expired EP0079761B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI813663A FI62887C (fi) 1981-11-18 1981-11-18 Grov i-balk
FI813663 1981-11-18

Publications (2)

Publication Number Publication Date
EP0079761A1 true EP0079761A1 (fr) 1983-05-25
EP0079761B1 EP0079761B1 (fr) 1986-02-26

Family

ID=8514880

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19820306003 Expired EP0079761B1 (fr) 1981-11-18 1982-11-11 Poutrelle I pleine

Country Status (5)

Country Link
EP (1) EP0079761B1 (fr)
CA (1) CA1196169A (fr)
DE (1) DE3269471D1 (fr)
DK (1) DK511282A (fr)
FI (1) FI62887C (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4669243A (en) * 1985-11-06 1987-06-02 Truswal Systems Corporation Fire protective system and method for a support structure
FR2599770A1 (fr) * 1986-06-09 1987-12-11 Jomard Daniel Portiques realises a partir de ctbx, debits de bois traditionnels et broches en tube
US5377472A (en) * 1992-02-06 1995-01-03 Terenzoni; Bob Timber system
FR2764622A1 (fr) * 1997-06-17 1998-12-18 Paul Henri Mathis Poutre composite armee a base de fibres vegetales
US5974760A (en) * 1993-03-24 1999-11-02 Tingley; Daniel A. Wood I-beam with synthetic fiber reinforcement
US6173550B1 (en) 1993-03-24 2001-01-16 Daniel A. Tingley Wood I-beam conditioned reinforcement panel
EP3919698A1 (fr) 2020-06-05 2021-12-08 Phylem Structures, Sl Système structural en bois modifié

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU4005597A (en) 1996-08-19 1998-03-06 Les Bois Laumar Inc. Steel-wood system
CA2192427C (fr) * 1996-08-19 2001-07-31 Marcel Leblanc Poutrelle en bois a renfort d'acier
CA2353202C (fr) 2001-07-17 2009-01-06 Guildo Deschenes Poutre de bois en i

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1825643U (de) * 1960-11-22 1961-01-26 Wilhelm Poppensieker Fa Stegplatte aus mehreren abwechselnd mit sperrholzschichten zusammengeleimten schichten.
DE7011426U (de) * 1970-01-12 1970-08-06 Oesterr Doka Schalung Kastentraeger aus holz.
FR2367883A1 (fr) * 1976-10-12 1978-05-12 Uhalde Bernier Sa Perfectionnements aux procedes de fabrication de charpentes en materiaux ligneux, procede tcp
GB1514879A (en) * 1976-10-22 1978-06-21 Nickerson & Co Ltd W Joints in wooden structural elements
DE8033681U1 (de) * 1980-12-18 1981-05-27 Achberger GmbH & Co KG, Karl, 8903 Bobingen Vorrichtung zum abstuetzen von bauelementen, schalungen o.dgl.

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1825643U (de) * 1960-11-22 1961-01-26 Wilhelm Poppensieker Fa Stegplatte aus mehreren abwechselnd mit sperrholzschichten zusammengeleimten schichten.
DE7011426U (de) * 1970-01-12 1970-08-06 Oesterr Doka Schalung Kastentraeger aus holz.
FR2367883A1 (fr) * 1976-10-12 1978-05-12 Uhalde Bernier Sa Perfectionnements aux procedes de fabrication de charpentes en materiaux ligneux, procede tcp
GB1514879A (en) * 1976-10-22 1978-06-21 Nickerson & Co Ltd W Joints in wooden structural elements
DE8033681U1 (de) * 1980-12-18 1981-05-27 Achberger GmbH & Co KG, Karl, 8903 Bobingen Vorrichtung zum abstuetzen von bauelementen, schalungen o.dgl.

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4669243A (en) * 1985-11-06 1987-06-02 Truswal Systems Corporation Fire protective system and method for a support structure
FR2599770A1 (fr) * 1986-06-09 1987-12-11 Jomard Daniel Portiques realises a partir de ctbx, debits de bois traditionnels et broches en tube
US5377472A (en) * 1992-02-06 1995-01-03 Terenzoni; Bob Timber system
US5974760A (en) * 1993-03-24 1999-11-02 Tingley; Daniel A. Wood I-beam with synthetic fiber reinforcement
US6173550B1 (en) 1993-03-24 2001-01-16 Daniel A. Tingley Wood I-beam conditioned reinforcement panel
FR2764622A1 (fr) * 1997-06-17 1998-12-18 Paul Henri Mathis Poutre composite armee a base de fibres vegetales
EP3919698A1 (fr) 2020-06-05 2021-12-08 Phylem Structures, Sl Système structural en bois modifié
WO2021245177A1 (fr) 2020-06-05 2021-12-09 Phylem Structures S.L. Système structural en bois d'ingénierie
EP4234832A2 (fr) 2020-06-05 2023-08-30 Phylem Structures, Sl Système structural en bois modifié
EP4234831A2 (fr) 2020-06-05 2023-08-30 Phylem Structures, Sl Système structural en bois modifié
US11846100B2 (en) 2020-06-05 2023-12-19 Phylem Structures, S.L. Engineered wood structural system

Also Published As

Publication number Publication date
CA1196169A (fr) 1985-11-05
FI62887B (fi) 1982-11-30
DE3269471D1 (en) 1986-04-03
EP0079761B1 (fr) 1986-02-26
FI62887C (fi) 1983-12-05
DK511282A (da) 1983-05-19

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