RU2773742C1 - Curved thin-walled metal profile - Google Patents

Abstract

FIELD: building.

SUBSTANCE: invention relates to the field of building, in particular, to a curved metal profile. Curved thin-walled metal profile comprises a side wall, coupled on both sides thereof, at an angle of 90°, with parallel shelves of equal width, and with a trapezoidal recess into the profile in the central part of the wall along the longitudinal axis of symmetry, formed by symmetrical inclined walls coupled with the base parallel to the side wall, wherein the trapezoidal recess is made with a height equal to the width of the shelf, and in the base of the recess, with a width equal to 0.25-0.35 of the height of the profile; a grooved corrugation with a width equal to 0.28-0.48 of the width of the base and a curvature described by a radius with a centre located in the longitudinal plane of symmetry of the profile equal to 0.14-0.52 of the width of the base is made along the longitudinal axis of symmetry into the recess.

EFFECT: increase in the bearing capacity of the profile.

2 cl, 6 dwg

Description

The invention relates to the field of ground construction, in particular to long bearing elements of building structures, namely to cold-formed rolled profiles and can be used in the production of load-bearing and connecting metal structures in shipbuilding, aircraft engineering, in construction and in the production of building structures, which can be widely used in production of sets of mating profiles for the manufacture of frames and spatial structures used in the construction of technical, economic and household facilities for various purposes.

A bent profile is known mainly for road barriers of highways, containing a horizontal side wall with a trapezoidal corrugation located in its middle, inclined side walls associated with horizontal shelves of given values, having flanges with a width equal to 4-4.5 of the profile thickness and inclined downward at an angle of 68 -72 0 to the shelves, while the angle of inclination between the inclined side walls and the horizontal wall is 100-104 °, the corrugation height is 0.18-0.22 of the profile height, and the corrugation width is 0.39-0.43 of the width of the horizontal walls (RU, No. 2124410 C1, IPC B21D 5/08 (1995.01), publ. 10.01.1999).

The formation on the basis of the known bent profile of joints in the manufacture of composite beams, frames and spatial structures is limited by the low variability of interfaces due to the small number of planes (two, less often three) to connect them into a structure. This profile is used mainly as racks, or horizontal bars connecting the racks, which requires additional fasteners for their assembly (slats, scarves, flanges, fasteners) and a large number of holes for bolted connections, weakening the sections of the connections, or local welding operations. , striking protective coatings and creating thermal stresses in the metal, leading to deformation of structural elements. In addition, the use of a known profile in the manufacture of metal structures, for example, composite beams with a length of more than 6-10 meters, is limited by the fact that the profile has a low transverse rigidity due to disproportions in the geometric shape of the cross section and a significant removal of the axis of application of loads to the element from the main central axes of inertia of the profile, which leads to a loss of stability and requires the strengthening of potentially unreliable beam elements.

The use of a well-known profile, for example, in shipbuilding, limits its technological capabilities, since ship structures made on its basis under the conditions of application of inertial and vibrational loads lead to complex “non-classical” loads on structural elements, distorting load diagrams and profile geometry (bending, twisting, etc.), which increases the likelihood of fatigue failure, reducing the service life.

In addition, the use of this profile with insufficient transverse rigidity is impractical in small-form architectural projects, shipbuilding for the formation of deck superstructures and railings, and aircraft industry.

A bent steel profile is known, containing two shelves with perpendicular bends directed towards each other, and a side wall between the shelves with a recess in the central part, forming ledges with a height exceeding the thickness of the profile, which is made 0.8-2 mm thick with the possibility of articulation and pairing of two profiles, while the shelves are made of different widths, with a difference equal to the double thickness of the profile, and the ledges are made of different heights, with a difference equal to the thickness of the profile, and the larger ledge is located on the side of the larger shelf (RU, No. 2478764 C1, IPC E04C 3 /07 (2006.01), published on April 10, 2013).

The composite building element formed as a result of conjugation of two profiles is a conjugated pair formed by a profile of the same type, the elements of which differ in size (bends, ledges, shelves), while their conjugated parts are connected by hardware at the points of contact, and the joints on each side of the pair are connected by overlays. The connection of profiles with hardware when forming beams, frames and spatial structures is possible only for short sections. Thus, for the formation of long structures, a significant number of sections is required, increasing the number of butt joints, which leads to an uneven distribution of stresses, worsening the bearing capacity of structures.

The closest analogue of the invention is a building element in the form of a bent thin-walled metal profile with a thickness of 0.8-1.2 mm, containing a side wall, coupled on both sides with parallel shelves of the same width, and made in its central part along the longitudinal axis of symmetry a trapezoidal recess inside the profile, forming ledges by symmetrical inclined walls with a height exceeding the thickness of the profile, coupled with a base parallel to the side wall, while the mating of the shelves and the side wall is made radial with the same value R = 2.8 mm at an angle of 90 ° (RU, No. 33046 U1, IPC B21D 5/06 (2000.01), E04C 3/07 (2000.01), E04C 3/32 (2000.01), E04D 12/00 (2000.01), published 10.10.2003).

The configuration of the cross section of this profile, in which the trapezoidal recess is made with a height much less than the width of the shelf, determines the orientation of the surfaces of the shelves and the base in different planes, while the profile side wall performs mainly a connecting function. As a result, under load application conditions, the resulting stresses are mainly distributed over the section of the flanges, while the profile has low rigidity in the middle part of the section, and, as a result, low bearing capacity and stability.

The formation of joints based on this profile in the manufacture of composite elements and structures in order to obtain the necessary rigidity and stability requires the use of profiles of a larger nominal value, or an increase in its thickness, or the use of additional elements reinforcing the section (plates, corners, etc.) with punching holes for fastening elements in certain places, which reduces the rigidity of the profile section and leads to a distortion of its geometry (bending, twisting, band diversity, etc.). As a result, this complicates the assembly due to the need to perform preparatory locksmith operations and complex welding work, increases the metal consumption and limits the possibility of using this profile in shipbuilding, power units, in the aircraft industry for the formation of power elements from aluminum and titanium with high plastic properties, mechanical engineering and construction metal frame structures in areas of high seismicity.

Thus, the technological capabilities of the known profile are limited in the formation of joints on its basis in the manufacture of composite beams, frames and spatial structures due to the low variability of interfaces with a low bearing capacity and stability of the profile.

The invention is based on the task of improving a bent thin-walled metal profile, in which, by changing the configuration of the cross section and geometric parameters, the optimal orientation of the surfaces of the profile elements is ensured with the possibility, under load conditions, of a uniform distribution of stresses over the section of the profile with increased rigidity, which leads to an increase in the variability of interfaces while increasing the bearing capacity and stability of the profile, expanding the technological possibilities of forming joints on its basis in the manufacture of composite elements and structures with a decrease in metal consumption.

The problem is solved by the fact that a bent thin-walled metal profile containing a side wall connected on both sides at an angle of 90 ° with parallel shelves of the same width, and with a trapezoidal recess made in its central part along the longitudinal axis of symmetry inside the profile, formed by symmetrical inclined walls , conjugated with the base parallel to the side wall, according to the invention, the trapezoidal recess is made with a height equal to the width of the shelf, and at the base of the recess with a width equal to 0.25-0.35 of the profile height along the longitudinal axis of symmetry, a grooved corrugation with a width of 0.28 is made inside the recess. -0.48 of the base width and curvature described by a radius with a center located in the longitudinal plane of profile symmetry equal to 0.14-0.52 of the base width.

It is advisable to make shelves with bends at right angles, directed towards each other, with a width equal to 0.10-0.25 of the shelf width.

The implementation of a trapezoidal recess with a height equal to the width of the shelf, the base of which is made with a width equal to 0.25-0.35 of the profile height, ensures the optimal orientation of the surfaces of the profile elements with the formation of a rectangular contour. At the same time, the surfaces of the shelves and the base of the trapezoidal recess are located in the same plane parallel to the plane in which the surface of the side wall is located, conjugated with the symmetrical inclined walls of the recess, which ensures, under load application conditions, a uniform distribution of stresses over the profile section with increased rigidity. Execution in the base of a trapezoidal recess along the longitudinal axis of symmetry inside the recess of the grooved corrugation with a width equal to 0.28-0.48 of the width of the base and a curvature described by a radius with a center located in the longitudinal plane of symmetry of the profile, equal to 0.14-0.52 of the width of the base , under load application conditions, provides additional resistance to bending and torsional moments, which leads to stress equalization along the profile section with an increase in rigidity in the middle part of its section.

Thus, it is possible to interface the profile on all four sides of its rectangular contour with an increase in rigidity, which leads to an increase in the variability of interfaces with an increase in the bearing capacity and stability of the profile, expanding the technological possibilities by forming joints on its basis in the manufacture of composite elements and structures with a decrease in metal consumption.

The essence of the invention is illustrated by drawings, where in Fig. 1 shows a bent thin-walled metal profile with a grooved corrugation in the form of a semicircle, cross section; in fig. 2 - bent thin-walled metal profile with a grooved corrugation in the form of a segment of a circle, cross section; in fig. 3 - bent thin-walled metal profile with flanges of shelves, cross section; in fig. 4 - composite beam in the form of a shelf I-beam, cross section; in fig. 5 - a composite beam in the form of a box-shaped I-beam, cross section: in Fig. 6 - a composite beam in the form of a box-shaped I-beam, made of profiles with limbs of the shelves, cross section.

The bent thin-walled metal profile contains a vertical side wall 1 connected on both sides at an angle of 90° with parallel shelves 2 of the same width. In the central part of the side wall 1, along the longitudinal axis of symmetry, a trapezoidal recess is made inside the profile, formed by symmetrical inclined walls 3, coupled with a base 4 parallel to the side wall 1. The trapezoidal recess is made with a height equal to the width of the shelf 2, and the base 4 of the recess is made with a width equal to 0 .25-0.35 profile height. At the base 4 of the recess along the longitudinal axis of symmetry inside the recess, a grooved corrugation 5 is made with a width equal to 0.28-0.48 of the width of the base 4 and a curvature described by a radius R with a center located in the longitudinal plane of symmetry of the profile, equal to 0.14-0, 52 base widths.

For example, with a profile height of 180 mm, the width of the base 4 of the recess, equal to 0.33 of its height, is 60 mm, while the width of the grooved corrugation 5, equal to 0.48 of the width of the base 4, is 28.8 mm. The grooved corrugation, with curvature, described by radius R with the center located in the longitudinal plane of symmetry of the profile, equal to 0.24 of the base width, which is 14.4 mm, is a semicircle in cross section (Fig. 1), and the grooved corrugation, by curvature, described by radius R2 with a center located in the longitudinal plane of symmetry of the profile, equal to 0.50 of the width of the base, which is 30 mm, represents a segment of a circle in cross section (Fig. 2).

In a bent thin-walled metal profile, the shelves 2 are made with bends 6 at a right angle, directed towards each other, with a width equal to 0.10-0.25 of the width of the shelf 2 (Fig. 3).

The manufacture of a bent thin-walled metal profile and the formation of joints on its basis in the manufacture of composite beams is carried out as follows.

The profiling process is carried out on a roll forming mill by passing a rolled strip of structural carbon steel grade St. 3 with a thickness from 1.0 mm to 5.0 mm through successively installed pairs of rolls-rollers. The profiling process is continuous and consists in changing the configuration of the cross-section of the workpiece, consistent in technological transitions, flexible with the corresponding calibrated rolls to ensure the orientation of the surfaces of the edges of the shelves 2 and the base 4 of the trapezoidal recess in one plane parallel to the plane in which the surface of the side wall 1 is located, conjugated with symmetrical inclined walls 3 recesses, providing the possibility of pairing the profile on the four sides of its contour.

At the initial stage of profiling, the strip is fed into calibrated rolls to form a longitudinal grooved corrugation 5 in the center of the strip with a width equal to 0.28-0.48 of the base width and a curvature described by a radius with a center located in the longitudinal plane of profile symmetry equal to 0.14 -0.52 the width of the base 4. Next, a trapezoidal recess is formed with a height equal to the width of the shelf 2, formed by symmetrical inclined walls 3 associated with the base 4 with a width equal to 0.25-0.35 of the profile height.

At subsequent stages, at the end sections of the strip, two equal symmetrical parts of the side wall 1 are formed with end sections, on which parallel shelves 2 of the same width are formed at an angle of 90° to the side wall 1.

In the same sequence, the process of manufacturing a profile with limbs of the shelves is carried out, in which at the final stage on the shelves 2 at an angle of 90 °, limbs 6 are made, with a width equal to 0.10-0.25 of the shelf width, directed towards each other.

Composite beams are made from pairs of profiles obtained by forming joints.

From two profiles with a grooved corrugation in the form of a semicircle, a beam is made in the form of a shelf I-beam (Fig. 4) by articulating the side wall 1 with the corresponding side wall of another profile. In this case, the articulation of the side walls of the profiles is carried out using bolted, riveted and welding joints (spot and relief welding). Also, this joint can be performed using thermal pads along the connector to prevent the formation of cold bridges in the structures of polar facilities. Under conditions of load application, the resulting internal stresses are perceived by all areas of the profile elements and are evenly distributed over the cross section of the beam, ensuring its stability.

A beam in the form of a box-shaped I-beam (Fig. 5) is made by articulating shelves 2 and bases 4 of a trapezoidal recess of both profiles, forming a communication channel with two grooved corrugations with a section in the form of a segment of a circle. In this case, the articulation of the shelves is carried out using welding joints (electric welding with an intermittent seam), and the bases of 4 recesses are made using bolted connections. Under conditions of load application, the resulting internal stresses are additionally perceived by the grooved corrugations and dissipated in the places of bends of the side wall of the profile, evenly distributed over the cross section of the beam, which increases the resistance to the combined action of bending and torsional moments, ensuring its stability. A beam in the form of a box-shaped I-beam has a high bearing capacity under conditions of a combination of shear and torsion loads, which is especially important in shipbuilding.

The manufacture of such beams from profiles with a grooved corrugation in the form of a semicircle, the shelves of which are made with limbs 6 at right angles directed towards each other, is carried out by articulating limbs 6 and bases 4 of the trapezoidal recess of both profiles (Fig. 6). At the same time, along with an increase in rigidity, it is possible to perform a “petal connection” of pair-sized profiles in the manufacture of T-shaped, L-shaped, and other structures, which significantly reduces the use of reinforcing strips, corners and welding joints that create negative stresses, reducing metal consumption .

The inventive profile can also be made from rolled sheets of cold-rolled carbon steel, galvanized in continuous galvanizing units with a thickness of 0.5 mm to 4 mm, increased accuracy of rolled products in thickness and width, and zinc coating up to 2.5 mm thick. This makes it possible to articulate galvanized profiles in the manufacture of structures by welding with spot or projection welding, followed by processing of welding points with insulating materials, while maintaining the zinc coating.

The use of the claimed invention leads to an increase in the variability of interfaces with an increase in the bearing capacity and stability of the profile, expanding the technological capabilities of the profile by forming joints on its basis in the manufacture of composite elements and structures with a decrease in metal consumption.

The proposed profile provides a variety of forms of constituent elements and structures with equivalent bearing capacities. The formation of joints on its basis in the manufacture of composite elements and structures can be carried out on all four sides of its rectangular contour without additional structural elements, using a combination of various types of joints, in particular, bolted, riveted and petal, spot-relief welding, as well as electric welding along shelves with an interrupted seam. At the same time, the formation process is simplified, it requires a smaller number of fasteners, and the fabricated structures have increased vibration resistance along the longitudinal axis of the profile, due to high rigidity. Also, due to the increased vibration resistance, the proposed profile can be used for the manufacture of spatial frames of enclosing structures of ship architecture, energy (diesel, gas turbine, etc.) blocks.

The use of the proposed profile with high bearing capacity compared with the closest analogue provides in the manufacture of composite elements an increase in its length to 25-30 m with a decrease in metal consumption up to 18-20%. Thus, the proposed profile has wide technological capabilities in the formation of joints on its basis in the manufacture of various forms of composite elements and structures with a reduction in total weight, which makes it possible to use it in architectural projects of small forms, shipbuilding for the formation of deck superstructures and fences, aircraft industry for the formation power rods made of aluminum and titanium with high plastic properties.

Claims (2)

1. A bent thin-walled metal profile containing a side wall, coupled on both sides at an angle of 90 ° with parallel shelves of the same width, and with a trapezoidal recess made in its central part along the longitudinal axis of symmetry inside the profile, formed by symmetrical inclined walls, coupled with a parallel side wall with a base, characterized in that the trapezoidal recess is made with a height equal to the width of the shelf, and at the base of the recess with a width equal to 0.25-0.35 of the profile height, along the longitudinal axis of symmetry inside the recess there is a grooved corrugation with a width of 0.28- 0.48 of the base width, and curvature described by a radius with a center located in the longitudinal plane of profile symmetry, equal to 0.14-0.52 of the base width. 2. A bent thin-walled metal profile according to claim 1, characterized in that the shelves are made with bends at a right angle, directed towards each other, with a width equal to 0.10-0.25 of the shelf width.

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