RU2056483C1 - Method for making curvilinear thin-walled members - Google Patents

Abstract

FIELD: civil engineering. SUBSTANCE: method for making curvilinear thin-walled members for example of roll steel includes forming profile on rolling mill. EFFECT: effective development of arched buildings in field conditions. 2 cl, 5 dwg

Description

 The invention relates to construction and can be used in the manufacture of elements for the construction of light frameless arched buildings.

 A known method of manufacturing curvilinear profiles on sheet bending rollers [1] This method can be obtained profiles of limited cross-section, since when rolling thin-walled profiles there is a local loss of stability in the compressed zones of the profile.

 There is another method of manufacturing thin-walled profiles [2] consisting in the use of pre-corrugated walls with subsequent welding to the shelves.

 The disadvantage of this method is that it is possible to produce only an I-profile, and the presence of welding requires the use of sufficiently thick sheets.

Closest to the invention in technical essence and the achieved effect is a method of manufacturing curved thin-walled elements of open section, which consists in forming a profile of a metal tape on a roller mill, followed by bending the entire profile on additional rollers [3]
The disadvantage of this method is that when creating the curvature of the thin-walled profile there is a local loss of stability of the compressed zones, which makes the use of these elements impossible.

 In the proposed method for manufacturing a curved thin-walled element, including forming a profile on a roller mill from a metal tape and giving the element a curvature, before forming the profile, the moving metal tape on both sides is subjected to a longitudinal non-uniform stretch of the tape width, which varies according to the following relationship.

Δ _x (R ₁ / R ₂ 1) (bx) / b, where Δ _x is the relative stretch along the width of the tape from the edges (x = 0) to the center of the tape (x _max b); R _{1 the} required external radius of curvature of the element; R _{2 is} the same, the inner radius; b the width of the shelves of the profile.

 Performing a preliminary stretching of the metal tape with its subsequent passage through the forming rollers provides a curved element, while the tape is drawn out with the least effort by lateral bending due to the passage of the tape between the bevel gear teeth or the triangular stamping device.

 Figure 1 shows the arch of a thin-walled profile made by the proposed method; figure 2 cross section aa in figure 1; figure 3 view along arrow B in figure 2; figure 4 is a perspective diagram of a technological line for the manufacture of curved thin-walled profiles; 5, node A in FIG. 4.

 A method of manufacturing a curved thin-walled profile of an open section is as follows. The metal tape 1 from the roll is sent (Fig. 4) to the devices for forming the profile. Before forming the profile of the element, a metal tape with a width b (Fig. 4) is subjected to a longitudinal stretch of uneven width of the tape on each side, for example, by passing it between the bevel teeth of gears 2 or by making triangular width stampings.

The value of the relative hood of the metal tape is taken as follows
Δ _x (R ₁ / R ₂ 1) (bx) / b.

After completing the drawing, the metal strip enters the molding rollers 3, where the profile is formed and its curvature is adopted along the radii R ₁ and R ₂ (Fig. 4). The curvature of the element is provided by flaring the edges of the tape within the width of the shelves of the profile. Since the upper edges are given a relative elongation Δ _{x = 0} , and the lower edges Δ _{x = b} (Fig. 3), the curvature of the element is achieved without compression deformations of the profile wall.

1

1 R₁/R₂-1 0,0266
Здесь S₁ длина дуги внешней кромки; S₂ длина дуги внутренней кромки.PRI me R. It is required to make an arched element of a thin-walled profile (Fig. 1) with an external radius R ₁ 12.16 m and an internal R ₂ 12 m. To obtain the specified curvature of the arch, the outer edge of the profile must be extended by
Δ _{x = 0} =

1

1 R ₁ / R ₂ -1 0.0266
Here S _{1 the} length of the arc of the outer edge; S _{2 the} length of the arc of the inner edge.

 The maximum value of the required relative deformation of the edges of the element is 2.66%. This deformation is provided due to the transverse bending of the edges of the sheet created by the bevel gear teeth or stamping. For example, with the lateral bending shape of the edges shown in FIG. 5, to ensure a relative longitudinal strain of 2.66%, it is necessary to assign K f / L (where f is the arrow of the wave; L is the wavelength).

K²; S/L 1,0266=

K² откуда f/L 0,1.From the Chebyshev formula (see Designer Handbook. Calculation and Theoretical. Vol. 1, M. Stroyizdat, 1972, p. 70) the length of an arc of one wave (Fig. 3) will be
SL •

K ² ; S / L 1.0266 =

K ² whence f / L 0,1.

 For example, at a wavelength of 50 mm, the arrow of its deflection f is equal to 5 mm. These options are used to select the size of the teeth or die.

 Thus, the proposed method allows without significant longitudinal and bending efforts to obtain a thin-walled curved element. The invention can most effectively be used for the manufacture of arch buildings in the field.

Claims (2)

1. METHOD FOR MANUFACTURING CURVILINEAR THIN-WALLED ELEMENTS, including forming a profile on a roller mill from a metal strip and imparting curvature to an element, characterized in that before the forming operation of the profile, a moving metal tape from both edges is subjected to longitudinal stretching, non-uniform along the width of the tape, according to the following varying dependence:
Δx = (R ₁ / R ₂ -1) (bx) / b,
where Δx is the relative stretch along the width of the tape from the edges (x = 0) to the center (x _{m a x} = b);
R ₁ is the required external radius of curvature of the element;
R ₂ is the inner radius of curvature of the element;
b is the width of the shelves of the profile.  2. The method according to claim 1, characterized in that the longitudinal non-uniform hood is performed by creating a transverse bend, for example, bevel gear teeth or a triangular stamp.

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