NL9300520A - Construction element and method of fabricating such a construction element - Google Patents

Abstract

The invention relates to a method for fabricating a construction element, starting from I-beams (H-beams) of a specific height, whose webs (bodies) are split longitudinally in two halves in accordance with a wave pattern. According to the method, the tooth crests of at least one of the two beam halves are directly joined to a separate plate which runs substantially parallel to the flange, integrated with the web plate, of said beam half. The invention also relates to a construction element which can be fabricated in such a manner.

Description

Title: Construction element and method for the production of such a construction element.

The invention relates to a construction element, such as an I-beam or a box girder, and to a method for the manufacture of such a construction element.

Metal construction elements, such as steel or aluminum I-beams or box girders, are available in a number of standard sizes. Box beams are often composed of a number of standard-size I-beams, two of which are placed next to each other, after which the flanges are welded together. In this way, box beams can be manufactured relatively economically, starting from large-length, part-rolled I-beams of standardized dimensions.

If a box girder or an I-beam with a dimension that deviates from the usual height is required, one of the following known solutions is optionally used: - the I-beam or box beam is manufactured from separate sheet parts, which are welded together; - an I-beam of normalized dimensions is selected, after which one of the flanges and part of the integrated web plate is cut off, so that a T-beam results. Then, a separate sheet is welded directly to the free longitudinal edge of the web plate to form the required flange. If this method is followed, a normalized I-beam always serves as the starting point, the height of which is greater than the height of the construction element to be manufactured therefrom. When the normalized I-beam is divided into two T-beams of equal height, but less than half the height of the starting material, a web plate strip is to be regarded as waste, removal of which requires an additional cutting operation. Greater material loss occurs when one of the two T-beams obtained from the I-beam is so low that it is no longer usable to use.

If the construction element is built up from separate plate parts to be welded together, a relatively expensive construction element results in view of the large number of welded joints to be made. Furthermore, there is also a risk of large cutting losses here, since the plate parts as a starting material are also usually normalized.

The object of the invention is to find a solution for the manufacture of construction elements with a freely selectable height within wide limits, substantially independent of the normalized height of generally available construction elements, with considerable reduction of material losses. It is proposed for this purpose to longitudinally divide an I-beam as starting material along a wave-shaped dividing seam, which is preferably square wave-shaped with sloping flanks or flanks directed substantially perpendicular to the flanges. In that case, the two web plate halves of the thus obtained beam halves have a sufficient height to function as a basis for the formation of an I-beam or box beam with a freely selectable height. As a result, cutting losses are minimal or even omitted. A separate plate can then be welded to the wave crests to obtain the desired I-beam or the box beam. An additional advantage is due to the presence of the wave valleys, with which lighting holes are immediately obtained after welding on the individual plate. Without any further processing and material loss, a lighter I-beam or box girder can thus be obtained with a bending strength and bending stiffness comparable to that of a corresponding solid construction element.

The invention is of course not limited to the use of welds for fixing the separate plate to the obtained beam half. Other joining techniques are also eligible.

It is known per se from the Dutch Laid-in Laying 86 00118, an I-beam with lighting holes to be manufactured from an I-beam of lower height, which is divided lengthwise according to a truncated sawtooth-shaped pattern, after which the halves are divided over the height of the tooth and are moved half a tooth distance relative to each other in the longitudinal direction, and then weld the tooth tips thus placed opposite one another. This publication does not teach how an I-beam or box girder can be manufactured from an I-beam of greater height without loss of material.

Obviously, what the present invention teaches is also applicable to halving, for example, sheet metal parts into two separate, economically usable sheet halves.

In the following the invention is further elucidated on the basis of some non-limiting exemplary embodiments with reference to the annexed drawings. Hereby shows:

Figure 1 is a diagrammatic perspective view of an I-beam as starting material for the present invention;

Figure 2 shows a view corresponding to figure 1 of the same I-beam after it has been cut longitudinally, with the two halves in the original position shown at a distance from each other;

Figure 3 shows a perspective view of the beam halves according to figure 2 assembled to form a box beam;

Figure 4 shows a view corresponding to figure 3, wherein the box beam has been completed by welding on a separate plate, which is shown partly broken away here; and

Figure 5 shows a perspective view of a beam half according to figure 2, assembled into an alternative I-beam.

Figure 1 shows an I-beam 1, consisting of two substantially parallel plate-forming flanges 2, with a web plate 3, likewise plate-shaped, which is oriented substantially perpendicular to the flanges 2. Such steel I-beams are rolled in one piece and are generally commercially available in various standard sizes. For example, such I-girders 1 are available in a number of heights for the body location 3, a number of widths for the flanges 2 and a number of thicknesses for both the body plate 3 and the flanges 2.

In accordance with the present invention, the body plate 3 is longitudinally cut along a slanting square-wave saw cut 4 as shown. As Figure 1 shows, the tops 6 and valleys of this saw cut 4 are equidistant from the respective flanges 2. Of course, instead of the square wave-shaped saw cut with sloping edges shown, a square wave-shaped saw cut with perpendicular edges can be used. A more or less wavy cut 4 with rounded transition from flank to top / valley can also be used. It is important that with the cut 4 the body plate 3 is cut alternately at higher and lower positions relative to the respective flanges 2. It is also not essential here that the tops and troughs of the cut 4 are at the same distance from the respective flanges 2. By varying these distances, construction elements of different heights can be manufactured.

After making the cut 4, two beam halves 5 result, as shown in figure 2. Because the cut 4 is arranged symmetrically around the central longitudinal axis of the beam 1, both beam halves 5 have the same height measured between the respective flange 2 and the tops 6 of the web plate 3. As can be seen from the drawing, the height of each beam half 5 is significantly greater than half the height of beam 1, but less than its total height.

To form a box beam 3, the two beam halves 5 shown in figure 2 are placed side by side as shown in figure 3, and welded together along the adjacent edges of the flanges 2. Then, as shown in figure 4, a flange plate 7 is placed on top of the tops 6 of the body plates 3, and welded thereto. There is thus obtained a box girder 8 which is largely composed of a commercially available I-beam. Due to the chosen wavy cutting pattern 4, used for cutting the I-beam in two halves, a box girder 8 can be manufactured without cutting losses, the height of the web plate of which is freely selectable in a wide area smaller than the web plate height of the I-beam as a starting material. In addition to almost completely avoiding cutting losses, the box girder 8 can also be assembled with a small number of weld seams from commonly available material. In addition, the box beam 8 thus composed naturally has lighting holes 9, which can also be used as feed-through openings, or when used in floor constructions as access openings to fill the beam with, for example, concrete for higher fire resistance.

According to figure 4, the additional plate 7 is placed on top of the tops 6 of the body plate 3, for example also a narrower plate 7, which fits exactly between the two parallel running plates 3, to be flush with the tops 6 The point is that the additional plate 7 is immediately connected to the tops 6.

As Figure 4 further shows, the plate 7 ends before the end of the plates 2. The part of the flanges 2 and the body plates 3 projecting beyond the plate 7 can for instance be cut off. However, it is also possible to let the plate 7 continue to run and to end flush with the flanges 2. By welding on extra sheet material, a direct connection can then be realized at that end of the box beam 8 between the flanges 2 and 7. It is also possible for one of the halves 5 in the assembly according to figure 3 in the plane of the flange 2. rotated through 180 °. As a result, the tops 6 are staggered with respect to each other, which provides symmetrical joining of the plate 7, and also delays the wrinkle formation in the plate 7 upon bending.

In accordance with the present invention, an I-beam can also be manufactured from one half 5 of an I-beam longitudinally halved with a wavy cut 4. As figure 5 shows, a plate 7 is welded to the tops 6 of the body plate 3 of the beam half 5 for this purpose. Again, by choosing the tops and valleys until the flanges 2, a beam height can be obtained which can be varied in a wide area within the height of the web plate of the I-shaped beam 1 as a starting material, without adverse cutting losses and at the same time under lighting hole formation 9.

Not important for the invention is the mutual width ratio between the plate 7 and the flange (s) 2.

Thus, the present invention provides a method for manufacturing I-girders and box girders from commercially available material, wherein the height of the products to be obtained can be selected almost independently of the height of the starting material by inventively cutting longitudinally and reassembling the starting material while minimizing any cutting losses.

Claims (5)

Method for manufacturing a construction element, starting from I-beams of a certain height, which in its body is split in two halves according to a wave pattern in the longitudinal direction, characterized in that at least one of the two beam halves (5), the tooth tips (6) are always directly connected to a separate plate (7), which runs substantially parallel to the flange (2) of the beam half (5) integrated with the web plate (3). Method according to claim 1, in which of two beam halves (5) the flanges (2) are placed parallel and next to each other, after which the adjacent flange edges are connected to each other, and the separate plate (7) with the wave tops (6) of both beam halves (5) are joined. Construction element comprising an integrated flange (2) and web plate (3), the free edge of the web plate (3) being of corrugated shape (4), and the tops (6) of that free edge of the web plate ( 3) are directly connected to a separate plate (7) which is substantially parallel to the flange (2). Construction element according to claim 3, comprising two side-by-side and parallel flanges (2) with integrated web plate (3), the web plates (3) each having a corresponding corrugated free edge, of which the wave tips (6) are directly connected to a separate common plate (7) which is oriented substantially parallel to the flanges (2). Construction element according to claim 3 or 4, wherein said free edge of the web plate (3) is of square wave form, with sloping or substantially perpendicular flanks (2).