JP2008240294A - Bent web H-section steel and method for manufacturing the same - Google Patents

Abstract

A bent web H-section steel and a method for producing the same are provided.
In an H-section steel in which a corrugation is formed in the longitudinal direction of a member on a web, the corrugation formed in the web 4 is spaced 0.5 to 1.5 times the beam dimension in the longitudinal direction of the member. In the direction of the beam, the range corresponding to the height dimension of 50 to 70% of the web dimension is alternately bent in the longitudinal direction of the member, and the ridges 5 and the valleys 6 and the inclination directions are different between them. The flat inclined web side plates 2 and 3 are alternately formed, and the height difference between the crest 5 and the trough 6 is 2 to 10 times the web thickness, and the crest 5 and trough The cross-sectional waveform of the web which is alternately repeated in the longitudinal direction of the member by 6 and the inclined web side plates 2 and 3 between them is substantially a triangular waveform. The web 4 is bent by hot working to give a substantially triangular wave-like bend across the web.
[Selection] Figure 2

Description

  The present invention relates to an H-shaped steel used as a structural member such as a column member for a column base structure of a steel column or a beam material, and in particular, a web is provided with alternately crests and troughs in the longitudinal direction of the member. Further, the present invention relates to a bent web H-shaped steel having improved shear buckling resistance (buckling rigidity) and a method for manufacturing the same.

  In general, when the cross-sectional area of the H-shaped steel is gathered at each flange portion, the secondary moment of the cross section becomes larger. Therefore, when the H-shaped steel is used as a bending material, the performance as a bending material becomes high. When it comes to webs, this will be thin, but there are limitations in terms of structural performance and manufacturing technology.

In terms of the structural performance, when a bending force is applied to the H-section steel 10 as shown in FIG. 7, for example, a shearing force as indicated by an arrow is simultaneously applied to the web 4. Since the web 4 bears the shearing force, if the thickness of the web 4 is too thin, the web 4 is buckled by the shear stress, and is no longer a place to bear the bending.
As shown by a two-dot chain line in FIG. 7, reinforcement by a rib (stiffener) 11 provided at a right angle to the web 4 in the direction between the flanges is effective for shearing acting on the web 4. Resistance can be increased. In the case of the rib (stiffener) 11 described above, the H-shaped steel material manufactured by rolling is used because it is arranged at right angles to the web 4 and has a clear directionality. Since it must be fixed by welding after cooling, there is a drawback that the production is complicated and the production cost is remarkably increased.
As an alternative to the rib 11, there is also known an example in which a steel plate shaped into a curved waveform having a large height difference in a short wavelength peak / valley with a very fine pitch of about 30 mm is used for a web (for example, Patent Documents). 1 and 2).
In the above case, since it is a curved waveform with a very fine pitch, it is necessary to process with a corrugated roll that contacts the entire surface of the curved waveform, which requires an expensive corrugated roll and always presses the web surface. Therefore, there is a problem that the cost of roll drive power increases. Further, in the case of a curved waveform web, since it is a curved waveform, there are many large semicircular portions near the top of the curved waveform, that is, many portions parallel to the web (in other words, the web ) And the direction crossing the web is reduced, the shear buckling resistance cannot be increased efficiently, and the design is not easy.

Moreover, in the manufacturing surface in the above case, after the hot rolling of the H-shaped steel material, the temperature is first lowered from the thin web, and then the temperature of each flange is lowered. As each flange cools, the temperature shrinks and a web that has already cooled and hardened is compressed and buckled.
The thinner the web is with respect to the flange, the more likely the web will wavy (buckling) and the lower the yield.
JP-A-6-328152 JP 2005-28442 A

Usually, the web weight of H-section steel accounts for 30 to 50% of the total weight of the H-section steel. Therefore, if the web weight can be reduced by 1/3 (for example, 9 mm can be reduced to 6 mm), Since the weight is close to 10 to 20%, the weight can be reduced and the cost is reduced. In addition, when corrugating the web, the H-shaped steel can be manufactured more economically without using the curved corrugated roll and without constantly pressing the curved corrugated roll on the web. When the ridges and valleys are alternately provided in the longitudinal direction of the member in the web, the length from the ridges to the valleys can be made extremely long compared to the conventional case, and the unit of the H-section steel The processing per length can be extremely reduced, the production can be performed efficiently, and the inclined web is provided so that almost all of the inclined web intersects the web center axis. The clarity of the direction can surely increase the shear buckling rigidity and the design is easy, and when other members are attached to the inclined web than in the case of the curved web. , Removing other parts It is desired that is facilitated.
For example, if the flange width dimension and flange plate thickness dimension are not changed with the same beam dimensions, the H-section steel is lightweight without changing the bending performance of the H-section steel (while maintaining the bending performance of the H-section steel). It is hoped that
An object of the present invention is to provide a folded web H-section steel that eliminates the above-described problems and makes it possible to reduce the weight of the H-section steel and a method for manufacturing the same.

In order to solve the above-mentioned problem advantageously, in the bent web H-section steel of the first invention, in the H-section steel in which the web is corrugated in the longitudinal direction of the member, the corrugation formed in the web is the member In the longitudinal direction, at intervals of 0.5 to 1.5 times the beam dimension, a range corresponding to a height dimension of 50 to 70% of the web dimension is alternately bent in the longitudinal direction of the member, and peaks and The flat inclined web side plates having different inclination directions are alternately formed between the valleys and the valleys, and the height difference between the peaks and the valleys is 2 to 10 times the thickness of the web plate. The cross-sectional waveform of the web that is alternately repeated in the longitudinal direction of the member by the crests and troughs and the inclined web side plates between them is substantially triangular.
In the second invention, the bent web H-section steel according to the first invention is characterized in that a portion having a substantially triangular waveform in the cross section is formed by hot rolling.
In the method for producing a folded web H-section steel according to the third aspect of the invention, the web of the H-section steel material produced by hot rolling is subjected to a folding process, and the web is substantially triangular across the web according to claim 1 or 2. The method is characterized in that corrugation is given.

According to the present invention, even if the web is thinned, the web is provided with the inclined web side plates that are alternately repeated in the longitudinal direction of the member. Therefore, it is possible to improve the web shear buckling resistance while reducing the weight of the H-shaped steel. A bent web H-shaped steel. Particularly in the case of the present invention, since the inclined web side plate crosses the longitudinal direction of the web, that is, a flat plate-like inclined plate, the direction of the inclined web side plate with respect to the web center axis is clarified, and by hot rolling A bent web H-section steel that can be easily manufactured can be obtained. Further, by thinning the web, it is possible to obtain an H-section steel that efficiently exhibits bending performance even with the same weight.
Further, the corrugation formed on the web has a height dimension of 0.5 to 1.5 times the beam dimension in the longitudinal direction of the member and 50 to 70% of the web dimension in the beam dimension. Only the corresponding range is alternately bent in the longitudinal direction of the member to form ridges and valleys, and the height difference between the ridges and valleys is 2 to 10 times the thickness of the web plate. Therefore, a practical bent web H-shaped steel material that can be manufactured can be obtained.
According to the second aspect of the invention, the portion having a substantially triangular waveform in the cross section is formed by hot rolling, so that the portion having a substantially triangular waveform can be easily and efficiently formed in the cross sectional waveform.
According to the third invention, the H-shaped steel web manufactured by hot rolling is bent to form the inclined web side plate having a substantially triangular waveform in the cross-sectional waveform. Processed webs can be processed efficiently and economically, and even for thin plate webs, the shear buckling resistance of H-section steel can be prevented while preventing the web from wavy during cooling. Can be easily increased.

  Next, the present invention will be described in detail based on the illustrated embodiment.

  FIGS. 1-5 shows the bending web H-section steel 1 of 1st Embodiment of this invention, Comprising: On the line of a hot rolling process on the web 4 of the H-section steel material manufactured by a hot rolling process The first inclined web side plate 2 and the second inclined web side plate 3 are formed so as to be alternately bent and intersected with the web center axis CL in the longitudinal direction of the member. Each of the inclined web side plates 2 and 3 is inclined so as to be displaced in the flange width direction with respect to the central axis line CT in the web ridge direction, and is flat and the first inclined web side plate 2 and the first inclined web side plate. The flat second inclined web side plates 3 having different inclination directions so as to intersect 2 are formed in the longitudinal direction of the member so as to be alternately arranged symmetrically. The said 1st inclination web side board 2 and the 2nd inclination web side board 3 are provided over the full length of the member continuously in the member longitudinal direction.

  The web by which the waveform by the said 1st inclination web side board 2 and the 2nd inclination web side board 3 is bend | folded so that it may incline in those connection parts (peak part 5 or trough part 6) and a web warp direction. Except for the connecting portion 7 from the flange side 4, it has a flat plate shape. In the illustrated embodiment, the connecting portion 7 from the flange side is also substantially flat. The flat plate shape described above clearly changes the direction of the inclined plate compared to the case of the curved waveform because the direction intersecting the central axis of the inclined plate is clearly changed. Accordingly, the number of plate portions in the flange width direction intersecting the web center axis CL increases, and the shear buckling rigidity increases and the design becomes easy.

  The corrugated cross-sectional shape of the first inclined web side plate 2 and the second inclined web side plate 3 is a cross section in which two equal sides (two sides) in which the bases in the isosceles triangle are omitted are alternately repeated in the longitudinal direction of the member. It is a shape. In the present invention, the web waveform cross-sectional shape in the longitudinal direction of the member in which two equal sides or two sides are alternately repeated in a cross section is referred to as a triangular waveform. The bent corner connecting portion (the peak portion 5 or the valley portion 6) between the first inclined web side plate 2 and the second inclined web side plate 3 is ideally bent, but in order to bend a thick steel plate. It is difficult to avoid a slight curvature in the refracting part in the roll processing or the press processing during the hot rolling. Therefore, the refracted portion of the first inclined web side plate 2 and the second inclined web side plate 3 has a slight curvature radius, and as a whole, has a substantially triangular waveform in the cross section in the longitudinal direction of the web 4.

  By alternately repeating the first inclined web side plate 2 and the second inclined web side plate 3 having different inclination directions, the waveform formed on the web 4 is the first inclined web side plate 2 and the second inclined web side plate 3. The distance between the crests 5 or the troughs 6 at the boundary (the width dimension in the side view of the inclined web side plates 2 and 3 in the longitudinal direction of the member or the crease line spacing between the crests and troughs) When the distance is set to 0.5 to 1.5 times the dimension, when the column member, the beam member, or the girder member is used, the wave pitch is not extremely fine, and the manufacture is easy. Moreover, when it exceeds 1.5 times the size of the beam, when it is used as a normal member, the number of repetitions of the crests 5 and troughs 6 is reduced, and the rigidity around the weak axis of the H-section steel is increased and the shear seat Since it may be difficult to increase the bending resistance efficiently, the above range is set.

Moreover, the range of the web ridge direction in which the said 1st inclination web side plate 2 and the 2nd inclination web side plate 3 are formed is set to the range symmetrical with respect to the central axis C of a member longitudinal direction, A range corresponding to a height dimension of 50 to 70% is alternately bent in the longitudinal direction of the member, and a crest 5 and a trough 6 are formed by intersections of the first inclined web side plate 2 and the second inclined web side plate 3. Is formed. It is ideal that the web is formed in the range of 100% in the direction of the web, but when the flange 8 is approached, the processing becomes difficult, and in the case of continuous bending on the hot rolling line, the direction of the beam is If it is formed in a size range of 70%, the shear buckling resistance can be sufficiently increased, and it can be processed economically. Further, in the range below 50% in the beam direction, the range in which the first inclined web side plate 2 and the second inclined web side plate 3 are formed is small, and there is a high possibility that the expected effect is small. Set.
Moreover, the height difference dimension from the web center axis CL of the peak part 5 and the trough part 6 by the intersection part of the 1st inclination web side board and the 2nd inclination web side board 3 is 2-10 times the web board thickness dimension. Set to dimensions.
When the height difference H between the ridge part 5 (mountain thickness center point) and the valley part 6 (valley part thickness center point) is less than twice the web plate thickness dimension t, the center of the ridge part from the web center axis. Alternatively, since the amount of shift E (the height of the peak 5 or the valley) of the peak 5 or the valley to the valley center is small and the shear buckling resistance (rigidity) cannot be increased efficiently, It is preferable to make it 2 times or more. Moreover, if the height difference dimension from the web center axis CL of the peak part 5 and the valley part 6 exceeds 10 times the web plate thickness dimension, the shift amount E of the peak part 5 or the valley part from the web center axis line CL is increased. Since it may become large and manufacturing by hot working may be difficult, the above range is set.

  As described above, the cross-sectional shape of the inclined web that is alternately repeated in the longitudinal direction of the member by the crests 5 and the troughs 6 formed by alternately repeating the first inclined web side plate 2 and the second inclined web side plate 3. In the case of the H-section steel 1 having a bent web having a substantially triangular waveform, the first inclined web side plate 2 and the second inclined web side plate 3 are substantially flat inclined side plates. (Buckling resistance) can be increased, and it can be provided more easily and economically than when a rib (stiffener) is provided. In addition, when attaching other members to the first inclined web side plate 2 and the second inclined web side plate 3, these inclined web side plates are flat face plates, so that attachment is much easier than in the case of a curved shape. Become.

  Note that the inclination angle of the first inclined web side plate 2 and the second inclined web side plate 3 with respect to the web center axis CL is theoretically greater than 0 degree and equal to or less than 90 degrees. It is good to set it in the range of more than 0 degree and 15 degrees or less.

As a method for forming the first inclined web side plate 2 and the second inclined web side plate 3, an inclined web side plate forming device is arranged on a hot rolling production line for producing an H-shaped steel material, and an H shape is formed. Before the steel material is cooled, as shown in FIG. 6 and FIG. 4, the pressing piece 9 driven by the pressing jack in the press working apparatus or the pressing piece 9 in the pressing roll driven by the driving apparatus is The web side plate between the pressing portions is arranged by pressing the intermediate portion of the web 4 in the web width direction from one side or both sides of the web 4 so as to be pushed out to the opposite side in the flange width direction. And the first inclined web side plate 2 and the second inclined web side plate 3 may be formed as the inclined web side plates.
For example, if the flange width is a narrow series H-section steel, medium-width series H-section steel or wide-series H-section steel, or a web-high H-section steel having a high web width, a liquid is placed on a line for rolling production. A pressing device (inclined web side plate forming device) having a web pressing piece 9 moved by a pressure jack or a pressing device having a plurality of pressing rolls having a pressing piece 9 is arranged and heated during hot working. It is preferable that the web 4 is pressed from both front and rear sides to be bent.

  By forming the first inclined web side plate 2 and the second inclined web side plate 3 in the normal hot-rolled H-section steel, a defective product due to a web wave (buckling) generated when the web is relatively thin. The thin web H-section steel 1 can be produced efficiently and economically.

  The bent web H-section steel 1 of the present invention may be an assembling-type H-section steel in a form in which a pair of flanges, a web including the first inclined web side plate 2 and the second inclined web side plate 3 are assembled by welding. If the web is processed on the line of the hot rolling process and manufactured, the manufacturing is easier, and the web can be manufactured at a lower cost. In addition, you may process into the web provided with the 1st inclination web side board 2 and the 2nd inclination web side board 3 by cold working to the web of the H-section steel material manufactured by a hot rolling process.

It is a side view which shows the bending web H-section steel of one Embodiment of this invention. (A) is a side view showing a part of FIG. 1 in an enlarged manner, (b) is a sectional view taken along the line aa of (a), and (c) is a cross-sectional plan view. FIG. 3 is a three-dimensional perspective view of FIG. (A) is the bb sectional view taken on the line of Fig.2 (a), (c) is the cc sectional view taken on the line of Fig.2 (a). It is a cross-sectional top view which expands and shows a bending web part. It is a cross-sectional top view which shows the case where it forms with a pressing piece, when forming a 1st inclination web side board and a 2nd inclination web side board. The conventional H-section steel is shown, Comprising: (a) is a side view, (b) is a front view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bending web H-section steel 2 1st inclination web side board 3 2nd inclination web side board 4 Web 5 Mountain part 6 Valley part 7 Connection part 8 Flange 9 Pressing piece 10 H-section steel 11 Rib

Claims (3)

  In the H-section steel in which the web is corrugated in the longitudinal direction of the member, the corrugation formed in the web is in the longitudinal direction of the member at intervals of 0.5 to 1.5 times the beam corrugation dimension. Then, the range corresponding to the height dimension of 50 to 70% of the web dimension is alternately bent in the longitudinal direction of the member, and the crests and troughs and the flat inclined web side plates having different inclination directions are alternately arranged therebetween. The height difference between the crest and trough is 2 to 10 times the thickness of the web plate, and the crest and trough and the inclined web side plate between them. A folded web H-section steel, characterized in that the cross-sectional waveform of the web that is alternately repeated in the longitudinal direction of the member is substantially triangular.   2. The bent web H-section steel according to claim 1, wherein a substantially triangular waveform portion in the cross section is formed by hot rolling.   A folded web H-shape characterized in that a web of an H-shaped steel material manufactured by hot rolling is subjected to a bending process to provide a substantially triangular wave-shaped bend across the web according to claim 1 or 2. Steel manufacturing method.

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