DE202023002652U1 - Truss girders with upper and lower chords made of solid wood, glued laminated timber (GLT) or structural solid timber (KVH) and filler bars made of debarked round timber - Google Patents

Abstract

Truss girder made of a combination of continuous chords (upper and lower chords) made of prismatic solid wood, glued laminated timber (BSH) or solid structural timber (KVH) and only debarked round timber as filling bars, characterized in that only debarked round timber (3) (freed of bast and bark) are used as filling bars between the upper chord (1) and lower chord (2).

Description

Timber trusses currently consist of prismatic timber cross-sections (solid timber), glued laminated timber (GLT) or structural solid timber (KVH). Both the continuous chords (upper and lower chords) and the filler bars are also made of (solid timber), glued laminated timber (GLT) or structural solid timber (KVH). The chords are usually connected to the filler bars using shaped sheet metal connections (slotted sheets with dowels) or screw connections. The tension members are also usually connected to the upper and lower chords using sheet steel connections (gusset plates with screws or dowels).

The invention specified in claim 1 is based on the problem of producing a truss girder from a combination of continuous chords (upper and lower chords) made of prismatic solid wood, glued laminated timber (GLT) or solid structural timber (KVH) and the filling bars from merely debarked round logs.

These filler bars made of debarked round wood, arranged perpendicular to the belts, only absorb compressive forces. The tensile forces that occur between the continuous belts are absorbed by the diagonal steel tension bars.

This means that debarked logs with a cross-cut parallel to the surface at both ends with a wood moisture content >20%<30% can also be used, since they are only subjected to compression parallel to the fibres and have negligible longitudinal shrinkage behaviour.

• 1 Teilstück eines Fachwerkträgers (Obergurt, Untergurt, Füllstäbe aus geschältem Rundholz, Zugstab)
• 2 Verbindung zwischen Gurt und Füllholz lediglich durch einen eingebohrten Stabdübel und Flächenpressung (Kontaktpressung)
• 3 Verbindung zwischen Gurt und Füllholz durch einen eingebohrten Stabdübel und Druckverteilungsplatte zur Reduzierung der Flächenpressung (Kontaktpressung) im Gurt
• 4 Anschluß der Zugstäbe aus Stahl an Gurt als durchgesteckter Stahlstab mit auf den Außenseiten der Gurte angebrachten Stahlblechen zur Aufnahme der Druckkomponente (rechtwinkelig zur Gurtachse) und horizontalen Zugkomponente (parallel zur Gurtachse) durch Verschraubung des Stahlblechs mit dem Gurt durch Vollgewindeschrauben, sowie Gewinde mit Spannmutter zur Vorspannung der Zugstäbe.

An embodiment of the invention is shown in the 1-4 explained. They show

• 1 Part of a truss girder (upper chord, lower chord, filler bars made of peeled round wood, tension bar)
• 2 Connection between belt and filler wood only by a drilled dowel and surface pressure (contact pressure)
• 3 Connection between the belt and the filler wood by means of a drilled dowel and pressure distribution plate to reduce the surface pressure (contact pressure) in the belt
• 4 Connection of the steel tension rods to the belt as a through-passed steel rod with steel sheets attached to the outside of the belts to accommodate the compression component (perpendicular to the belt axis) and horizontal tension component (parallel to the belt axis) by screwing the steel sheet to the belt using fully threaded screws, as well as a thread with a tension nut to pre-tension the tension rods.

List of reference symbols

1

Upper chord made of prismatic solid wood, BSH, KVH

2

Bottom chord made of prismatic solid wood, BSH, KVH

3

Filling rod made of peeled round wood

4

Tension rod

5

Rod dowel

6

Pressure distribution plate

7

Sheet steel

8th

Full thread screw

9

Thread with clamping nut

Claims (5)

Truss girder made of a combination of continuous chords (upper and lower chords) made of prismatic solid wood, glued laminated timber (BSH) or solid structural timber (KVH) and only debarked round timber as filling bars , characterized in that only debarked round timber (3) (freed of bast and bark) are used as filling bars between the upper chord (1) and lower chord (2). Trusses according to Claim 1 characterized in that these filling rods are only connected to the upper chord (1) and lower chord (2) by means of an embedded rod dowel (5). Truss girder according to one of the preceding claims , characterized in that a pressure distribution plate (6) can be arranged for load distribution between the filling bars (3) and the upper chord (1) or lower chord (2). Truss girder according to one of the preceding claims , characterized in that the connection of the tension rods (4) to the upper chord (1) and lower chord (2) takes place as a through-passed steel rod with steel sheets (7) attached to the outer sides of the chords, which are fastened to the upper chord (1) and lower chord (2) with fully threaded screws (8). Truss girder according to one of the preceding claims , characterized in that the connection of the tension rods (4) to the upper chord (1) is a through-threaded steel rod with Clamping nut (9) can be used to preload the tension rods.

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