RU2619293C1 - Beams junction in one level - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: in the beams junction in one level, consisting of the secondary beam, resting at the main beam through the angle seat, the main beam has the corrugated wall of the optional profile. The angle seat is welded to the main beam shelf by welded joint, laid along its longitudinal axis, and the width of the angle seat shelf is above 1/2 of shelf width of the main beam and not less than in 15 mm.

EFFECT: increase of the junction bearing capacity.

6 dwg

Description

The invention relates to the field of construction, in particular to metal structures, and can be used in frame structures of buildings and structures.

Known interface node of the secondary beam with the main beam at the same level through the reference corner (Series 2.440-2 release 1. Steel structure units of industrial buildings of industrial enterprises, sheet 03KM, node 3. - URL: http://dwg.ru/dnl/1752 ) Taken as a prototype.

The disadvantage of this node is that the bolts that attach the support corner to the shelf of the main beam weaken the cross section of the shelf. In addition, the load transferred from the secondary beam to the main beam is offset from the axis of the main beam. In this regard, the action of a concentrated load with displacement leads to the appearance of cramped torsion and, consequently, an increase in the level of stresses in the cross section of the main beam. If the main beam is designed without safety margins, then additional stresses from constrained torsion will lead to a loss of the bearing capacity of the main beam structure and the building as a whole. The load transferred from the secondary beam to the main beam is concentrated and is applied to the overhang of the shelf. A significant amount of concentrated load can lead to a loss of local stability of the main beam flange.

The technical result of the invention is to increase the bearing capacity of the interface, as well as the design of the main beam as a whole under the action of a concentrated load with displacement.

ширины полки главной балки не менее чем на 15 мм.The technical result is achieved by the fact that in the known node for joining beams at one level, consisting of a main beam and a secondary, as well as a connecting corner connecting them, welded to the end of the secondary beam, the feature is that the main beam has a corrugated wall of arbitrary profile, and the support corner is attached to the shelf of the main beam with a weld laid along its longitudinal axis, while the width of the support corner shelf exceeds

the width of the shelf of the main beam is not less than 15 mm.

The invention is illustrated by drawings.

In FIG. 1 shows a perspective view of a beam interface at one level, where the following designations are adopted: 1 — shelf of the main beam, 2 — corrugated wall, 3 — secondary beam, 4 — support corner.

In FIG. 2 shows a side view of the beam interface at the same level, where the following designations are adopted: 1 - shelf of the main beam, 2 - corrugated wall, 3 - secondary beam, 4 - supporting corner.

In FIG. 3 shows section AA in FIG. 2, where the following designations are accepted: 1 - a shelf of the main beam, 2 - a corrugated wall, 3 - a secondary beam, 4 - a reference corner.

In FIG. 4 shows a view A in FIG. 2, where the following designations are accepted: 1 - a shelf of the main beam, 3 - a secondary beam, 4 - a reference corner.

In FIG. 5 is a diagram of a beam for constrained torsion calculation, where the following notation is adopted: L is the length of the main beam, P is the vertical concentrated load, e is the load displacement relative to the axis of the main beam.

In FIG. 6 shows a diagram of the cross section of a beam with a flat wall and a corrugated wall before and after calculation, where the following notation is used: P - vertical concentrated load, e - load displacement relative to the axis of the main beam.

The proposed node for joining beams at one level consists of a main beam with a corrugated wall 2 of an arbitrary profile, for example a sinusoidal, secondary beam 3 made of a rolled profile or a welded beam, and a reference angle 4. The supporting corner 4 is attached by one weld to the external side of the shelf of the main beam 1, and the second shelf to the end part of the secondary beam. The weld on the flange of the main beam 1 is located along its axis, while the size of the flange of the reference corner 4 intersects the longitudinal axis of the flange of the main beam 1 by at least 15 mm. Through the reference angle 4, the concentrated load is transferred from the secondary beam 3 to the main beam. This concentrated load will be transmitted with an offset relative to the axis of the main beam.

Fixing the reference angle with a weld along the axis of the flange of the main beam avoids weakening the cross section of the flange, and the longitudinal location of the welds increases the reliable operation of the interface. The overlap of the flange of the reference angle beyond the longitudinal axis of the flange of the main beam moves the point of application of the concentrated load transmitted from the secondary beam and increases the local stability of the flange of the main beam. Replacing a flat wall in the main beam with a corrugated one increases the stiffness of the main beam for torsion, which makes it possible to better absorb the load applied with displacement.

To prove the advantage of the corrugated wall of the main beam compared to a flat wall, the bearing capacity of the main beam - the prototype - was calculated for the load with displacement transmitted from the secondary beams, and compared with the calculation of the beam with the corrugated wall for the same load.

For two beams, finite element calculations were performed using the Lira program for constrained torsion. Numerical experiments were performed for models of a two-support articulated beam of the same cross section (Fig. 5). The length of the main beam L = 6 m without loosening the belts in length.

Beam section:

- geometric dimensions of the section:

- height of the corrugated wall: h _w = 500 mm;

- corrugated wall thickness: t _w = 2.5 mm;

мм;- width of the shelf of the main beam:

mm;

мм;- shelf thickness of the main beam:

mm;

- corrugation parameters for a corrugated wall:

- corrugated wall profile: wavy;

- corrugation length: a = 77.5 mm;

мм.- corrugation height:

mm

The beam is loaded with two vertical concentrated loads P = 65 kN, applied in 1/3 of the span, in order to create a clean bend area (Fig. 5). The displacement of the concentrated load relative to the axis of the main beam is e = 40 mm, which corresponds to the location of the load outside the corrugation height.

The calculation showed that the rotation angles for the beams are as follows (Fig. 5):

- beam with a flat wall: -8.73 °;

- beam with corrugated wall: -7.02 °.

A beam with a corrugated wall turns out to be less sensitive to a load displaced relative to the axis than a beam with a flat wall, a smaller angle of rotation of the section indicates this. With the same parameters, a beam with a corrugated wall has greater torsional rigidity and, therefore, a corrugated beam is preferable from the point of view of its deformability. This advantage is 19.6%.

Using the proposed technical solution allows to increase the bearing capacity of the interface node, as well as the design of the main beam as a whole under the action of a concentrated load with displacement.

Claims (1)

A node for joining beams at one level, consisting of a main beam and a secondary, as well as a supporting corner connecting them, welded to the end of the secondary beam, characterized in that the main beam has a corrugated wall of arbitrary profile, and the supporting corner is attached to the shelf of the main beam with a weld, laid along its longitudinal axis, while the width of the flange of the reference angle exceeds

the width of the shelf of the main beam is not less than 15 mm.

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