RU2561446C1 - Manufacturing method of pre-stressed h-beam - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: manufacturing method of a pre-stressed H-beam provides for a design that consists of a lower flange, a web and an upper flange, which are connected by a weld. In order to produce an H-beam with tension of edges of the web and flanges, which work for compression, without any bending of the product after pre-stress, the following process is performed: the lower flange and the web, which are welded, are bent towards the web; the upper flange is welded to the tension part of the web; then, the lower flange is separated from the structure, which in its turn is bent to the reverse side, and the lower flange is welded to the tension side of the web. Tension in upper and lower flanges and edges of the web is the same; the beam takes up a straight-line position.

EFFECT: improving beam performance.

7 dwg

Description

The present invention relates to the manufacturing technology of metal building structures, namely to the manufacture of prestressed beams.

A known method of manufacturing structures of a prestressed metal beam, which consists of a composite beam consisting of an upper belt, a wall and a lower belt, to which pre-tensioned elements are fastened is made of high-strength steel, which are stretched mechanically or electrothermally (see E.I. Belenya "Pre-stressed load-bearing metal structures", M., Stroyizdat, 1975, pp. 119-121).

The disadvantage of this method of manufacturing the beam is the low voltage efficiency, metal consumption, while the tension process is very complex.

Closest to the technical nature of the claimed invention is a method of manufacturing a beam of I-section with the possibility of creating a prestress made by bending the Tauri external load applied to the belt of the Taurus until the appearance in the extreme lower zone of the wall stresses equal to the calculated resistance of mild steel with subsequent connection to the preliminary curved brand of the missing belt (see Iodchik A.A. The dissertation for the academic degree. Ph.D. FSBEI HPE Pacific States University “Research of the stress-strain state of steel thin-walled beams pre-stressed by bending of the Taurus”, Ulan-Ude, 2013, specialty 05.23.01, p. 32-40).

A disadvantage of the known method of manufacturing a metal beam of I-section is that the stress state of the wall is only on one side (compression, and on the other hand, bottom, tensile, and it is desirable that both belts have the same sign, for example, compression). The beam has a curved profile and its extreme parts are supported by the edges (the ends of the beam) not linearly, but linearly, which increases the load by 1 cm ² . Due to its curvature, such a beam cannot be used as a crane - the hoist will skid during its movement on the rise, and spontaneously roll when moving downhill.

The technical result of the invention is to improve the performance of an I-beam with tension of the edges of the wall and shelves of the I-beam, working in compression, without bending the product after prestressing, which gives a double voltage of the beam.

The technical result is achieved by the fact that in the method of manufacturing a prestressed I-beam, consisting of a wall and lower and upper shelves, including a bend of the wall and the lower shelf, fastening the upper shelf to the stretched upper part of the wall, according to the invention, after attaching the upper shelf to the wall, the lower shelf is separated from the I-beam, and the upper shelf and the wall are additionally bent in the opposite direction, after which the lower shelf is attached to the stretched lower part of the wall.

Thus, the difference between the method of manufacturing a prestressed I-beam, from the prototype, is:

- additional beam deflection, which allows to increase its bearing capacity;

- the rectilinear position of the beam, which simplifies its use in structures.

The invention is illustrated by drawings, where:

- in FIG. one:

a) shows the shelf and wall in the initial state;

b) a shelf and a wall are shown with welding in the initial state in a transverse section;

- in FIG. 2:

a) shows the bend of the structure towards the wall;

b) shows a cross section of the bend of the structure towards the wall;

- in FIG. 3:

a) shows the fastening of the shelf to the stretched wall;

b) shows the fastening of the shelf to the stretched wall in a transverse section;

- in FIG. four:

a) shows how the lower shelf is separated;

b) depicts how the lower shelf is separated in cross section;

- in FIG. 5:

a) the beam is bent in the opposite direction;

b) shows a cross section of the beam bend in the opposite direction;

- in FIG. 6:

a) shows the fastening to the stretched area of the lower shelf;

b) shows the fastening to the stretched zone of the lower shelf in cross section;

- in FIG. 7:

a) shows a finished prestressed beam with a double bend in a straight position;

b) a finished prestressed beam with a double bend in a rectilinear position in a transverse section is shown.

The design of the prestressed metal I-beam consists of a lower shelf 1, a wall 2 and an upper shelf 3, which are connected by a weld 4.

The process of tension of an I-beam is carried out as follows: the bottom shelf 1 and wall 2 are bent toward the side of the wall, the upper shelf 3 is welded to the stretched part of the wall 2, then the lower shelf 1 is separated from the structure, which in turn is bent in the opposite direction, and the lower shelf 1 is welded to the stretched side of the wall 2. The stresses in the upper and lower shelves 1, 3 and the edges of the wall 2 are the same, the beam takes a straight line position. Due to the fact that the I-beam has a double voltage, this can dramatically increase its performance. Since the middle part of the wall 2 is less stressed compared to its upper and lower parts, this allows you to more evenly transfer the load from the upper shelf 3 to the lower 1 and vice versa. The I-beam is evenly laid on the supports, since it is not bent (before it lay only in the extreme parts). An I-beam can be used as a crane, the hoist will evenly move along its entire length, and on a curved beam slip on a rise and spontaneously move downhill.

In the process of stress in the beam, stresses occur that are opposite in sign to the stresses that occur under the action of the operating load. During beam operation, these stresses are used primarily, thus increasing the elastic work of the beam.

The mechanisms for beam bending are weights, anchors and jacks (not shown in Figs. 1-7).

The present invention in comparison with the prototype (see Iodchik A.A. Thesis for the academic degree of the so-called FSBEI HPE Pacific State University "Research on the stress-strain state of steel thin-walled beams prestressed by bending of the brand", Ulan-Ude, 2013, specialty 05.23.01, p. 32-40) has the following advantages:

- improving performance;

- uniform load transfer from the upper shelf to the lower and vice versa;

- the use of an I-beam as a crane.

A beam is the main and simplest structural element working in bending, where it is exposed to a transverse load or external pairs, while bending moments occur in its sections, i.e. internal moments, the plane of action of which is perpendicular to the plane of the cross section of the beam.

Claims (1)

A method of manufacturing a prestressed I-beam, consisting of a wall and lower and upper shelves, including a deflection of the wall and the lower shelf, attaching the upper shelf to the stretched upper part of the wall, characterized in that after attaching the upper shelf to the wall, the lower shelf is separated from the I-beam and the upper the shelf and the wall are additionally bent in the opposite direction, after which the lower shelf is attached to the stretched lower part of the wall.

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