RU2704071C1 - Composite combined i-beam - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to construction, particularly, to combined beam structures. Composite combined double-tee beam, consisting of composite wooden belts joined into rigid structure by means of mechanical links, obtained by breaking the beam along length along wavy line, and thin wall from crosswise corrugated steel sheet, is reinforced with thickening of longitudinal wall edges, at least in connection zone with belt components.

EFFECT: invention is aimed at increasing carrying capacity and rigidity of the beam.

6 cl, 4 dwg

Description

The invention relates to the field of construction, in particular to the designs of combined I-beams used as load-bearing elements of coatings and ceilings of low-rise buildings.

Known composite metal beam I-beam, including the upper and lower shelves made of coniferous wood, interconnected by means of overlays located along the length of the beam with the possibility of ensuring a constant distance between the shelves. The shelves are made of composite elements with profiled faces, with which they are facing each other and fastened together along the length of the beam, the profiled wall in the upper and lower parts is located between the composite elements. Between the shelves installed supporting elements that are fastened together. [Patent for utility model of the Russian Federation No. 96144, dated March 18, 2010, IPC E04C 3/292, Bulletin No. 20 dated July 20, 2010].

The disadvantages of this design is the large number of parts required for the manufacture of beams, complicating the process. Lack of access to the wall of the beam and, in this regard, the complexity of monitoring the state of the beam under the overlays.

Known metal-wooden I-beam, consisting of a metal wall stitched on pins or screws with double-sided wooden belts and parallel double-sided ribs. [Patent for utility model of the Russian Federation No. 129960, dated 09.01.2013, IPC Е04С 3/292, Bulletin No. 19 dated 10.07.2013]. The ribs in the beam are abutted with equal pitch in the belts and are made ascending from the supports. The ribs with belts in the joints of the joint are connected by gear plates or metal plates on the pins.

The disadvantages of this design is the large number of components required for the manufacture of beams.

Closest to the invention is a composite combined I-beam, including composite wooden belts, obtained, for example, by dissolving a prismatic beam along the length of a wavy line, and a transversely corrugated steel wall placed between the parts of the belts connected in a rigid structure using metal pins [Patent for Utility Model of the Russian Federation No. 151745, dated December 23, 2013, IPC E04C 3/12, Bulletin No. 10 dated April 10, 2015].

The disadvantage of this beam is the low bearing capacity and structural rigidity, the need for a large number of metal pins, ensuring the joint work of a thin wall and belts.

The technical result of the invention is to increase the bearing capacity and stiffness of a composite combined I-beam.

The technical result is achieved by the fact that a composite combined I-beam, consisting of connected in a rigid structure, using mechanical ties, wooden composite belts obtained by dissolving the beam along the length along the wavy line, and a wall of transversely corrugated steel sheet, reinforced by thickening the longitudinal edges of the wall, at least in the zone of connection with the components of the belts.

Strengthening of the edges of the wall by thickening was obtained by symmetrical assembly and rigid connection of a packet of wavy strips of the same or another structural material with higher physicomechanical properties of the same or variable step width, gradually tapering to the periphery.

Strengthening the edges of the wall by thickening can also be obtained by rolling, welding or rolling with bending, not less than the height of the belt, by 180 ° of the longitudinal edges of the steel sheet of the wall before it is corrugated.

The technical result is also achieved by the fact that the beam is additionally reinforced with longitudinal stiffness diaphragms of angular cross-section, located on the inside of the component parts of the belts, corresponding in length and width, rigidly attached to the thickened part of the wall, a shelf adjacent and coinciding with its wavy contour, while the component parts of the belts are installed between the thickened part of the wall and the bent shelf of diaphragms of rigidity at odds.

Mechanical bonds connecting the beam into a rigid structure are passed through bent shelves of stiffness diaphragms, increasing the number of cut planes and the bearing capacity of the joint.

The axes of mechanical bonds with respect to the longitudinal axis of the beam are arranged in plan at an angle unequal 90 °, for example, according to the zigzag pattern, which, on the one hand, reduces the weakening of the cross sections of wooden belts, and on the other hand, increases the area of collapse in the steel wall.

The invention is illustrated by graphic images.

In FIG. 1 shows a composite combined I-beam in isometry, which shows: a component of the belt 1, wall 2, mechanical connection 3, diaphragm stiffness 4, thickening 5.

In FIG. 2 is a cross-sectional view of a composite combined I-beam of FIG. 1, with a thickening obtained by symmetrical assembly and rigid connection of a packet of wavy bands, which shows: a component of the belt 1, wall 2, mechanical connection 3, diaphragm stiffness 4, thickening 5.

In FIG. 3 is a cross-sectional view of the composite combined I-beam of FIG. 1, with a thickening obtained by rolling, welding or rolling to corrugate the steel sheet of the wall, where it is shown: a component of the belt 1, wall 2, mechanical connection 3, diaphragm stiffness 4, thickening 5.

In FIG. 4 shows a top view (in plan) of one of the belts with the arrangement of the axes of mechanical bonds 3 at an angle to the longitudinal axis of the beam unequal 90 °, according to the zigzag scheme.

The composite combined I-beam consists of upper and lower wooden belts. Each belt is formed by the dissolution of the beam along the length along the wavy line into two components, between which there is a transversely corrugated thin wall 2 of steel sheet.

The components of wooden belts can also be made in a different way, for example, by molding, gluing and pressing in purposefully laid waste of mechanical processing or specially cut wood material (longitudinally oriented chips, veneer). With a small height of the corrugation of the steel wall 2, the components of the belts can be obtained from solid or glued wood by pressing it, crushing across the fibers. It is known that the transverse shear deformations in wood are large, which is explained by its porous anisotropic structure with the smallest elastic modulus in the transverse direction. This technology will simplify the manufacture of component parts of the belts 1, locally densifies and hardens wood, and also eliminates woodworking waste.

The components of the belts 1 and the wall 2 of the combined beam are interconnected in a rigid structure using mechanical connections 3, for example, made in the form of pins or cords. Wooden belts should be made of high-quality solid or glued coniferous wood of strength class with a bend of at least K24 and treated with an antiseptic.

In addition, the beam is equipped with longitudinal stiffness diaphragms 4 of angular section located on the inside of each component part of the belt 1, which correspond to the length and width of the component part of the belt 1 and welded to the wall 2 by an adjacent shelf, the edge of which coincides with the wavy contour of the wall 2.

The longitudinal edges of the wall 2, at least in the area of connection with the components of the belts 1 and the diaphragms of rigidity 4, are made with a thickening 5.

According to one of the options, the thickening 5 of the wall 2 is achieved by bending (rolling) 180 ° of the longitudinal edges of the thin steel sheet of the workpiece, rolling or welding performed before the operation of transverse corrugation of the steel sheet.

In another embodiment, the thickening 5 of the wall 2 is achieved by symmetrical assembly and rigid connection of the packet of corrugated metal strips by contact welding, or by layer-by-layer gluing from the same or another structural material of the same or variable step width, gradually tapering to the periphery.

Thickening 5 of the longitudinal edges of the thin metal wall 2 enhances its resistance to local collapse and shear under mechanical bonds 3 and at the same time rationally distributes stronger and more rigid material in places of the greatest longitudinal deformations and stresses arising from lateral bending.

The components of the belts 1 are inserted between the thickened edge of the wall 2 and the bent shelf of the diaphragms of rigidity 4 at a time.

The longitudinal diaphragms of rigidity 4 limit, when the beam is bent, the development of horizontal deformations pushing the components of the belt 1 caused by the wavy shape of the transverse corrugated wall 2, while unloading the mechanical bonds 3, the number of which can be halved. In places where the beam is supported and the action of large concentrated forces, the thin transversely corrugated wall 2 can be additionally reinforced with transverse stiffeners made in wood or metal.

Taking into account the operating conditions, all elements of the combined beam should have special protective coatings (anticorrosive, hydrophobic, fireproof).

Assembling a composite combined I-beam is performed on the stand in the following sequence.

The component parts of the belts 1 of the beam perform dissolution along the length of the wavy line of the wooden beam. When dissolving the timber by sawing, the width of the cut must correspond to the thickened section of the wall 2, while ensuring the installation of the components of the wooden belts by surprise, for example, by means of a press fitting.

Through holes for mechanical connections 3 in one of the components of the belt 1 can be drilled in advance, in order to further use them as guides.

To obtain a thickening 5 of the wall 2 according to one of the beam manufacturing options, the longitudinal edges of the steel sheet of the billet for wall 2 are bent by 180 ° no less than the height of the wooden belt, then the sheet is transversely corrugated.

According to another manufacturing option, thickening beams 5 can be obtained by symmetrical assembly and rigid joining, for example, by contact welding or gluing a packet of corrugated metal strips of the same or another structural material, of the same or variable step width, tapering to the periphery.

Variability of the strip width reduces the dangerous effect of stress concentration in the transition zone from the thickening 5 to the wall 2 of a thin steel sheet.

The stiffness diaphragms 4 of the angular section can be made, for example, by cutting along the wavy line of the wall of a metal bent channel or cutting a rectangular strip with subsequent bending (flanging) 90 ° of one of the edges of the workpiece.

The longitudinal diaphragms of rigidity 4 of angular cross-section, located on the inner side of the components of the belts 1, corresponding to the length and width of each of them are welded to the thickened part of the wall 2 with a shelf adjacent to it and coinciding with its wavy contour.

The connection of the components of the girders 1 of the beam with the wall 2 is carried out by means of mechanical connections 3, dowels or strands passed through the bent shelves of the diaphragms of rigidity, or only through the components of the belts 1 and the wall 2, without capturing the diaphragms of rigidity 4.

The passage of mechanical connections 3 additionally through the bent shelves of the diaphragms of rigidity 4 increases the number of slices and the bearing capacity of the connection.

The arrangement of mechanical ties 3 along the length of the beam with a corrugated steel wall affects the bearing capacity of the joint, determined from the conditions of shearing of the beam materials, as well as depending on the shear and bending of the mechanical bond 3.

In addition, the mechanical bonds 3 experience tension due to the wavy geometry of the wall 2, which tends to fold between the parts of the compressed upper zones and straighten between the parts of the extended lower zones when the beam is bent.

The most dangerous type of stress-strain state in a thin steel wall 2 is a tear or shear of metal.

Thickening 5 of the longitudinal edges of the wall 2 increases the bearing capacity of mechanical bonds 3 for dangerous types of resistance.

The arrangement of mechanical bonds 3, symmetric by the condition of the crushing of wood, assumes equal thicknesses of the components of the wooden belts. In this case, the step of mechanical connections 3 should be consistent with the places where the wall intersects the median plane of the beam.

When arranging mechanical ties 3 along the crests and hollows of the waves, the areas of crushing of the wood of the component parts 1 of the belts will be different, which introduces asymmetry into the strength work of the joint, and their calculation is uncertain.

The location of the axes of the mechanical connections 3 in the plan with respect to the longitudinal axis of the beam at an angle of 90 ° to the longitudinal axis of the belts weakens the cross sections of the belts.

A more rational arrangement of the axes of the mechanical links 3 in the plan should be considered their location at an angle greater or less than 90 °, for example, according to the zigzag scheme.

Due to the thickening of the 5 longitudinal edges of the wall 2 and the stiffness diaphragms 4, the bearing capacity and stiffness of the composite combined I-beam increases, while the required number of mechanical connections 3 is significantly reduced, because the need for them is dictated mainly by ensuring the structural integrity of the structure, partial perception of tensile forces, arising in the belts during beam bending, as well as the effect of possible drying and swelling of the wood during operation, under conditions of temperature fluctuation and azhnosti.

The concentration of the material of the steel wall due to the thickening of its longitudinal edges, the reinforcement by the longitudinal diaphragms of the stiffness of the corner section, holds back the dangerous expansion deformations of the composite wooden belts, increases the reduced moment of inertia and the moment of resistance of the structural cross-section of the structure, and generally increases the bearing capacity and stiffness of the claimed composite combined I-beam.

Claims (6)

1. Composite combined I-beam, consisting of connected in a rigid structure using mechanical ties, wooden composite belts obtained by dissolving the beam along the length along the wavy line, and a wall of transversely corrugated steel sheet, characterized in that it is reinforced by thickening the longitudinal edges of the wall, at least in the zone of connection with the components of the belts. 2. A composite beam according to claim 1, characterized in that the reinforcement of the edges of the wall by thickening is obtained by symmetrical assembly and rigid connection of a packet of wavy strips of the same or another structural material with higher physicomechanical properties of the same or variable step width, gradually tapering to the periphery. 3. The composite beam according to claim 1, characterized in that the reinforcement of the edges of the wall by thickening is obtained by rolling, welding or rolling with bending, not less than the height of the belt, by 180 ° of the longitudinal edges of the steel sheet of the wall before it is corrugated. 4. The composite beam according to claim 1, characterized in that it is additionally reinforced with longitudinal stiffness diaphragms of angular cross section located on the inside of the component parts of the belts, corresponding in length and width, rigidly attached to the thickened part of the wall, with a shelf adjacent and coinciding with its wavy contour, while the component parts of the belts are installed between the thickened part of the wall and the bent shelf of diaphragms of rigidity at odds. 5. The composite beam according to paragraphs. 1 and 4, characterized in that the mechanical connection is passed through bent shelves of diaphragms of rigidity. 6. The composite beam according to claim 1, characterized in that the axis of the mechanical bonds with respect to the longitudinal axis of the beam are arranged in plan at an angle not equal to 90 °, for example, according to the zigzag pattern.

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