CN1702258A - Thin-wall open section steel with connection rod - Google Patents

Abstract

This invention provides open thin-wall steel with connecting bar, namely cold gagging thin-wall joggling channel. The technical project comprises: setting the open thin-wall steel including sternum, flange and curled edge, setting connecting bar between the opening, wherein two ends of the bar are connected with the upper and lower curled edge or the upper and lower flange. The ultimate span between connecting bars is no more than half of the distorted half-wave of the steel. The numerical calculation analysis indicates that said project could improve the distortion variable load of the steel over 20~30%; besides, it improves the bearing capacity of section steel, making the property being used absolutely.

Description

The thin-wall open section steel of connecting rod is set

Technical field

The present invention relates to steel member commonly used in a kind of building, bridge, the various device support, be specifically related to a kind of clod wash thin-wall open section steel.

Background technology

China's output of steel has surpassed America and Japan's sum, ranks first in the world in continuous 9 years, and steel enlarge day by day in the range of application of China, and quantity grows with each passing day.Considering to improve the technical-economic index of material, is must needing that current market is growing, competition becomes more fierce.Therefore, the application of light gauge cold-formed steel shape in building, bridge, various device support is increasingly extensive, and such one can save and uses material, two can alleviate deadweight, be convenient to transportation and install, thereby reduce comprehensive cost.In the clod wash thin-wall open section steel, the cold bending thin wall lipped channel is the most extensive in actual application in engineering.

But as can be known by theory analysis and experimental study, after the wall thickness of cold bending thin wall lipped channel is thinned to a certain degree, under pressure, moment of flexure or both actings in conjunction, cripling or distortional buckling will appear, the critical load of its flexing may can not be fully utilized the performance of material much smaller than the critical load of integrated member.In the engineering design, usually avoid the generation of cripling and distortional buckling, make and further to save steel by the wall thickness of restriction thin-wall open section steel member.

Summary of the invention

In order to solve in the prior art, distortional buckling appears in the cold bending thin wall lipped channel, and the critical load of its flexing may be much smaller than the critical load of integrated member, the problem that makes the performance of material can not be fully utilized and exist

The invention provides a kind of thin-wall open section steel that connecting rod is set-cold bending thin wall lipped channel of handling through structure, make its original shaped steel have bigger distortional buckling critical load than same model, thereby improve the supporting capacity of this shaped steel, the performance of material is fully utilized to reach purpose more economical, that be suitable for.

The technical scheme that the present invention takes is: a kind of thin-wall open section steel that connecting rod is set, comprise web 1, the edge of a wing 2, crimping 3, and connecting rod 4 is set between the shaped steel opening.

Described connecting rod 4 two ends are connected with the crimping up and down of shaped steel respectively; Or connecting rod 4 two ends are connected with the last bottom flange of shaped steel respectively.

Maximum spacing between the connecting rod is no more than half (can equal half-wavelength half) of the distortional buckling half-wavelength of thin-wall open section steel.

The distortional buckling half-wavelength l of thin-wall open section steel _dShould try to achieve by theoretical calculating of distortional buckling, also can calculate by following formula to lipped channel:

$l_d=3.2t{\left(\frac{b}{t}\right)}^{0.82}{\left(\frac{d}{t}\right)}^{0.7}[1+\frac{1}{8}(\frac{h}{b}-1)]$

In the formula, t is the wall thickness of shaped steel, and b is the width on the edge of a wing, and d is the height of crimping, and h is the height of web.

Connecting rod can adopt metal or nonmetals to make, and its size is determined by the slenderness ratio ([λ]=200]) of allowing that pressurized supports.

The connected mode on the connecting rod and the upper and lower edge of a wing is for using welding, anchor, clamping, bonding or other simple and reliable methods of attachment.

The spacing of connecting rod can be uniform, or arrange as the case may be.

Numerical Analysis shows, adopted technique scheme after, the press-bending distortional buckling load of same model thin-wall open section steel generally can improve 20～30% or more than; Improved the supporting capacity of shaped steel, the performance of material is fully utilized.

Description of drawings

Fig. 1: the lipped channel schematic diagram that connecting rod is set

Fig. 2: A-A sectional drawing

Reference numeral: web 1, the edge of a wing 2, crimping 3, connecting rod 4, holdfast 5.

The specific embodiment

Below in conjunction with accompanying drawing the present invention is described in further detail.

As shown in Figure 1, a kind of thin-wall open section steel that connecting rod is set comprises web 1, the edge of a wing 2, crimping 3, and connecting rod 4 is set between the shaped steel opening.

Described connecting rod 4 two ends are connected with the crimping up and down of shaped steel respectively; Or connecting rod 4 two ends are connected with the last bottom flange of shaped steel respectively.

Maximum spacing between the connecting rod is no more than half (can equal half-wavelength half) of the distortional buckling half-wavelength of thin-wall open section steel;

The distortional buckling half-wavelength l of opening thin lipped channel _dCan calculate by following formula:

$l_d=3.2t{\left(\frac{b}{t}\right)}^{0.82}{\left(\frac{d}{t}\right)}^{0.7}[1+\frac{1}{8}(\frac{h}{b}-1)]---\left(1\right)$

In the formula, t is the wall thickness of channel-section steel, and b is the width on the edge of a wing 2, and d is the height of crimping 3, and h is the height of web 1.

Connecting rod 4 can adopt metal or nonmetals to make, and its sectional dimension is determined by slenderness ratio ([λ]=the 200]) condition of allowing that pressurized supports, promptly should be satisfied the following formula requirement

$\mathrm{\λ}=\frac{l_1}{i_{\min }}\≤200---\left(2\right)$

λ and l in the formula ₁Be respectively the maximum slenderness-ratio and the length of connecting rod, i _MinThe least radius of gyration for the connecting rod cross section.

The connected mode on the connecting rod and the upper and lower edge of a wing is for using welding, anchor, clamping, bonding or other simple and reliable methods of attachment.

Embodiment 1, as shown in Figure 2, a kind of thin-wall open section steel-lipped channel, connecting rod 4 two ends are connected with crimping up and down with holdfast 5 respectively.Get web 1 height h=120mm, the edge of a wing 2 width b=90mm, crimping 3 height d=15mm and wall thickness t=1.5mm.

By formula (1) calculates the half-wavelength l of this shaped steel generation distortional buckling _d=720mm.Connecting rod adopts steel plate bar, thickness t ₁=1.4mm, width b ₁=2mm, length l ₁=80mm, the then least radius of gyration in cross section

$i_{\min }=\sqrt{\frac{I_{1,\min }}{A_1}}=\frac{{\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="A20051004984400082.png"\; state="\{\{state\}\}">t</figure-callout>}}_1}{\sqrt{12}}=\frac{1.4}{\sqrt{12}}=0.404\mathrm{mm}$

A in the formula ₁And I _{1, min}Be respectively the area and the least moment of inertia in steel plate bar cross section.

The maximum slenderness-ratio of steel plate bar connecting rod

${\mathrm{\&lambda;}}_{\max }=\frac{l_1}{i_{\min }}=\frac{80}{0.404}=198<200$

Satisfy formula (2) requirement, used connecting rod cross section is suitable.

The spacing of getting connecting rod 4 respectively is S=720mm, 360mm (=l _d/ 2), 180mm and 72mm.The results shows, after this lipped channel is provided with above-mentioned connecting rod, removes S=l _dOutside=the 720mm, supporting capacity has improved 30～52%, sees the following form.

Table 1 adds the supporting capacity of the forward and backward lipped channel of connecting rod under the eccentricity pressure effect relatively ^*

Pressure eccentric distance e (mm)	No connecting rod	Connecting rod interval S=l d? ??＝720mm	Connecting rod interval S=l d/2 ? ??＝360mm	Connecting rod interval S=l d/4 ? ??＝180mm	Connecting rod interval S=l d/10 ? ??＝72mm
						??5	??65.8	??65.8	??85.3	??86.0	??86.0
??15	??49.9	??49.9	??76.0	??76.5	??76.5
						??25	??40.5	??40.5	??60.0	??60.2	??60.5
??30	??36.8	??36.8	??54.5	??54.7	??55.3
						Simple bending	??2.2	??2.2	??3.3	??3.3	??3.3

* supporting capacity unit is: kN or kNm.

Embodiment 2, a kind of thin-wall open section steel, and connecting rod 4 two ends are connected with last bottom flange with holdfast 5 respectively, and all the other are with embodiment 1.

Embodiment 3, a kind of thin-wall open section steel, and connecting rod 4 two ends connect with the upper and lower volume side weld respectively, and all the other are with embodiment 1.

Embodiment 4, a kind of thin-wall open section steel, and weld with last bottom flange respectively at connecting rod 4 two ends, and all the other are with embodiment 1.

At last, it is also to be noted that what more than enumerate only is specific embodiments of the invention.Obviously, the invention is not restricted to above embodiment, many distortion can also be arranged.

The present invention can summarize with other the concrete form without prejudice to spirit of the present invention and principal character.Therefore, no matter from which point, above-mentioned embodiment of the present invention all can only be thought can not limit the present invention to explanation of the present invention, claims have been pointed out scope of the present invention, and scope of the present invention is not pointed out in above-mentioned explanation, therefore, in implication suitable and any change in the scope, all should think to be included in the scope of claims with claims of the present invention.

Claims (5)

1, a kind of thin-wall open section steel that connecting rod is set comprises web (1), the edge of a wing (2), crimping (3), it is characterized in that, connecting rod (4) is set between the shaped steel opening.

2, the thin-wall open section steel of connecting rod is set according to claim 1, it is characterized in that, described connecting rod (4) two ends are connected with the crimping up and down of shaped steel respectively; Or connecting rod (4) two ends are connected with the last bottom flange of shaped steel respectively.

3, the thin-wall open section steel of connecting rod is set according to claim 1, it is characterized in that, the maximum spacing between the described connecting rod is no more than half of distortional buckling half-wavelength of thin-wall open section steel;

The distortional buckling half-wavelength l of opening thin lipped channel _dCan calculate by following formula:

$l_d=3.2t{\left(\frac{b}{t}\right)}^{0.82}{\left(\frac{d}{t}\right)}^{0.7}[1+\frac{1}{8}(\frac{h}{b}-1)]$

Wherein, t is the wall thickness of shaped steel, and b is the width of the edge of a wing (2), and d is the height of crimping (3), and h is the height of web (1).

4, the thin-wall open section steel of connecting rod is set as claimed in claim 1 or 2, it is characterized in that, the size of connecting rod (4) is determined by the slenderness ratio ([λ]=200]) of allowing that pressurized supports.

5, the thin-wall open section steel that connecting rod is set as claimed in claim 1 or 2 is characterized in that, connecting rod (4) is welding, anchor, clamping or bonding with the connected mode of shaped steel.

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