JP3701862B2 - High strength joint construction method for steel structures - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to a technical field in which one-side welding is performed on a building structure, a bridge structure, a general structure, or the like. The present invention relates to a welding method for increasing the height and width of a front bead, or after performing overlay welding on the back surface of the end surface portion of a welded joint member, including groove joint processing including the welded joint member and the overlay welded portion. By using a joint welding method, or by bending the end of the member and then performing groove welding on the member, the joint is welded, so that one side of the member is used without using a consumable backing metal or backing material. It is related with the method of the technique which acquires the throat thickness exceeding the plate | board thickness or plate | board width of the member of the welded joint member end surface part by joint welding by the one-side welding method welded from.
[0002]
[Prior art]
FIG. 1 is a cross-sectional view showing an example of conventional steel frame welding. The member 1 and the member 2 which has been grooved at 35 degrees are butt welded by a T-joint, and a temporary welding 4 is performed by applying the backing metal 3 from the back side in order to stably weld completely from one side. Then, joint welding 6 is performed as shown in FIG. Therefore, in the prior art, as shown in FIGS. 1 and 2, a joint with a backing metal that is constructed from one side is standard for welding of steel frames such as buildings.
[0003]
In the conventional method, after the groove processing of the joining end portion of the member is performed, the backing metal is manufactured and the temporary welding for attaching the backing metal is performed. Therefore, joint welding cannot be performed immediately after the groove processing. In order to avoid this problem, enormous costs and time are required to remove the attached backing metal by gouging or the like and obtain a sound joint weld.
[0004]
Further, in the conventional method, the backing metal is left without being removed after welding, so that a harmful notch remains between the member and the backing metal, and stress concentration occurs. For this reason, it is also a factor which causes deterioration of seismic strength.
[0005]
Further, in the conventional method, or place a pre-weld bead 13 in front of the joint weld on the surface of the steel diaphragm 1 in the T-piece as shown in FIG. 11, to the surface and opposing steel diaphragm 1 in the T-piece as shown in FIG. 12 Although the method of placing a weld bead on the groove back surface of member 2 has been announced in advance, it is difficult to align the groove due to the dimensional tolerance of the member and irregular welding of the build-up weld bead. There are limitations on the workability and so on.
[0006]
Also, unlike the welding of square pipes and round pipes where the welding start point and end point overlap, when welding the end of a flange of H-shaped steel, the flange width becomes finite, and the welding end and end are to obtain a defect-free good welding, in the conventional method, since it is necessary to steel end-tab 13, the take much manufacturing cost and mounting steps of the end tabs. The use of ceramic end tabs instead of the steel end tabs has been increasing recently, but in this case as well, expensive production costs and mounting work made of ceramics are required. In addition, the steel end tab has a notch that causes stress concentration between the tab and the flange, and the ceramic end tab has a drawback that welding defects are likely to occur.
[0007]
[Problems to be solved by the invention]
In the conventional method, as shown in FIG. 1, there are two recessed corners 1R and 2R in the root portion of the groove 5 where the members 1 and 2 are in contact with the backing metal. As shown in FIG. 1 and FIG. 2, after processing the groove 5, the production of the backing metal 3 and the temporary welding 4 for attaching the backing metal are required, and the joint welding efficiency surface Therefore, since the backing metal 3 is left unattended in the subsequent joint welding 6, the harmful notch and the backing metal 3 and the base material 1 that cause stress concentration due to the residual of the temporary welding 4 are obtained. No. 7 and 7A, which cause stress concentration between the first and second, remain, which is a factor that hinders joint performance such as bending ductility, fatigue strength, and earthquake resistance. In the experiment, when the member 2 was subjected to an upward bending load 2B in the joint type of FIG. 2, a crack occurred at the notch 7 or 7A, which was almost harmful, and the joint was broken.
[0008]
Further, the conventional method shown in FIG. 1 and FIG. 2 requires the provisional welding 4 for manufacturing the backing metal 3 and attaching the backing metal after the groove processing of the end surfaces to be joined of the members. Since the welding 6 of the joint cannot be started immediately, there is a disadvantage that it takes a large number of man-hours to manufacture the steel frame in terms of the manufacturing process procedure.
[0009]
Also, in the conventional technology, if the backing metal 3 is omitted, it is necessary to perform reverse wave welding to create a well-shaped corrugated bead from the front side of the groove to the back surface of the first layer. Since it is difficult to maintain the groove accuracy due to the dimensional accuracy of the steel, difficult to secure the back welding technique, and difficult to use a large current from the first layer, it is difficult to realize this.
[0010]
In addition, it is possible to use a consumable backing material to form a good back bead, but this method has a problem that the consumable backing material is expensive and requires installation and removal work. . If made in the space inside it is closed as Joint portions of building steel frame shown in FIG. 14 is also a problem that can not be removed in the backing material of the depletable after welding. To deal with these problems, as shown in the series of construction sequences of FIGS. 15 to 18 , the end surface of the member to which the end surface of the T joint is welded is assigned a non-melting backing material such as copper, and the back side is overlaid. There is a method in which welding is performed, groove processing is performed including the overlay welded portion, and main welding is performed in contact with the mating member. This method solves these problems, but in the case of a small-diameter square steel pipe, it is narrow and welded when applying non-melting backing material such as copper to the end face and performing overlay welding on the back side, that is, the inner side. There is a problem of workability.
[0011]
In addition, according to “Architecture Standard Specification JASS6 Steel Construction” dated February 20, 1997 and “Steel Precision Measurement Guideline” dated July 1, 1998 of the Architectural Institute of Japan, for example, in a T joint having a thickness of 40 mm or less, FIG. As shown in FIG. 4 and FIG. 4, the extra height of the member 2 at the surface position of the counterpart member 1 only satisfies the dimension from 25% of the plate thickness t to 25% of the plate thickness t plus 10 mm. It is stipulated that it should change smoothly from the surface of the base material. This rule is effective to reduce the stress concentration of the front bead, but the height at the center of the bead is allowed to be zero, and the effect of the height at the center of the bead is not mentioned. Therefore, in such a bead, the stress concentration of the root portions 7 and 7A of the joint weld 6 is increased by the bending moment 2B and the tensile force 2C in FIG. 3, and the root portions 7 and 7A easily crack. Cheap. As shown in FIG. 4, when the backing metal 3 and its temporary welding 4 are provided on the back surface, stress concentration occurs on the root portion and the toe portion 4 </ b> A of the temporary welding portion in addition to the root portion 7 of the joint welding 6. In particular, cracks are easily generated from the toe 4A.
[0012]
On the other hand, as shown in the construction method of FIG. 11 , after the overlay welding 13 is placed on the member 1 that is not the end face of the T joint in advance, the first layer welding 14 from the front side of the groove to which the member 2 is applied. There is a method of performing joint welding 6 after that. Although this method has the convenience that the backing metal can be omitted, the position of the build-up weld 13 is determined in advance in addition to the unevenness of the wave of the build-up weld bead, so that the dimensional accuracy of the members is not constant. The adjustment and change of the position is not easy, the construction is difficult if the welding posture is not horizontal, the member 1 in FIG. 11 needs a certain inclination for forming the back bead, the first layer from the surface There are problems such that the welding 14 requires skill and cannot use a large current, and does not lead to an increase in the throat thickness 2A.
[0013]
Further, as shown in FIG. 12, the weld overlay beads 13 and 13 </ b> A are placed in advance on the back surface of the member 2 whose end face is grooved in addition to the surface of the member 1 of the T joint, and then the front side of the groove to which the member 2 is applied. There is a method in which the first layer welding 14 is performed and then the joint welding 6 is performed. There is convenience that this method can be omitted backing metal, but there is the same problem as Fig. Further, welding is not easy at the time of the overlay welding 13A to the distal end of the member 2 of Figure 12, moreover, it is necessary to put each to advance two positions overlay welding to the members of the T-piece, from FIG. 15 As shown in the series of construction methods leading to FIG. 18 , the welding is performed using a backing material that does not melt only to the member to which the end faces are joined, and then performing the groove processing including the built-up portion and joint welding. In comparison, there are problems of difficulty in welding and an increase in the number of manufacturing steps.
[0014]
In addition, end tabs are often used to weld the finite length of the H-shaped steel flange in the longitudinal direction to the end of the flange in the width direction and to obtain soundness at the start and end. Since the use of the end tab requires a manufacturing cost and a mounting cost, an inexpensive and easy construction method that omits the end tab is desired.
[0015]
[Means for Solving the Problems]
The present invention relates to one-sided welding of steel structures, etc., reducing manufacturing man-hours in terms of joint welding efficiency, reducing steel man-hours in terms of manufacturing process procedures, improving ease of position adjustment between joint members, welding construction Improved notch, increased throat thickness, and harmful notches that cause stress concentration between the backing metal or end tab and the base metal, and harmful notches that cause stress concentration on the backing metal attachment The purpose of the present invention is to eliminate the obstruction factor of the joint performance by controlling the shape of the joint weld bead of the last layer on the front side, or by forming a groove face larger than that formed by the joint member itself. To do.
[0016]
In order to improve the joint performance among the problems to be solved by the invention, the conventional joint shown in FIG. 2 is strengthened to detoxify the harmful notches 7 and 7A on the back surface and the temporary weld bead notch 4A on the backing metal. In order to solve all of these problems, the corners of the 1R and 2R roots in FIG. 1 are eliminated, and the production of the backing metal and the temporary welding that require a lot of man-hours are omitted. It is necessary to eliminate notches and increase the throat thickness.
[0017]
Therefore, in the method according to the first aspect of the invention, when one-side welding is performed in a butt weld joint in which T-shaped members are substantially perpendicular to each other, the conventional joint shown in FIG. 5A and 7A, as shown in FIG. 5, on the side of the member 2 to which the end faces are joined, the position 6T of the weld bead toe on the front side is the mother of the position 7 to 2A of the weld root part on the back side. Desirably separated by 80% or more of the thickness t of the material, and preferably located 1.5t away from the base material thickness t of 2A, i.e., 6B ≧ 0.8t in FIG. The surface bead overfill height in the entire region of the weld bead width on the back surface and the surface bead overfill height 6H in the back surface weld root portion is at least 10 of the plate thickness t. More than 15% and hopefully 15% or more and 25% or less Is secured, performs welding as excess weld the final layer of the joint weld 6 changes smoothly from the base metal surface of the bonding weld member 1 to member 2. If such welding is performed, the thickness of the notch portion on the back surface of the T joint increases, the stress concentration on the back surface notch portion is reduced, and the strength is strengthened against the tensile load 2C and bending moment 2B of the member 2. improves. In this case, the reason why the welding work range is desirably 1.5 times or less of the base metal sheet thickness t is to prevent an increase in welding distortion and an increase in welding work cost.
[0018]
In the method according to the first aspect of the present invention, when there is temporary welding of the backing metal as shown in FIG. 6, the welding bead toe portion on the front side from the toe portion 4A which is the stress concentration portion of the backing metal. The distance 6B to the position of 6T is 80% or more of the base material plate thickness t of 2A, and is preferably 1.5t away from the base plate thickness t of 2A, that is, 6B in FIG. ≧ 0.8t, preferably t ≦ 6B ≦ 1.5t, and at least the height of the front bead in the entire area of the weld on the back surface and the front bead at the back surface weld root The extra height 6H is secured at least 10% or more of the plate thickness, preferably 15% or more and 25% or less, and the extra layer of the final layer of the joint weld 6 extends from the base material surface of the joint weld member 1 to the member 2 Welding work so that it changes smoothly.
[0019]
In the method according to the first aspect of the present invention, when one-side welding is performed in a butt joint in which two members to be joined are substantially in the same plane, two joints using a square steel pipe are used as shown in FIG. The position of the toe when the weld bead toe 6T on the front side is at the thin side 2 of the members 2 and 12 and the weld bead root 7 on the back surface or the backing metal 3 is temporarily welded It is welded so that it is located more than 80% of the plate thickness, preferably 2A plate thickness t, ie, 6B ≧ 0.8t in FIG. 7 and t ≦ 6B ≦ 1.5t. In addition, at least 10% of the thickness of the front bead is ensured in the region of the weld bead width on the back surface, and preferably 15% or more and 25% or less, and the surplus changes smoothly from the surface of the base material. Welding work as follows.
[0020]
【Example】
Embodiments of the invention will be described with reference to the drawings.
[0021]
An embodiment of the invention according to claim 1 will be described mainly with reference to FIG. 5, FIG. 6 and FIG.
[0022]
FIG. 5 is a typical view for explaining a method according to the present invention in the case of performing one-side welding with a backing metal at a butt weld joint in which T-shaped members are substantially perpendicular to each other. In FIG. 5, the welding is sequentially performed from the first layer to the conventional method. However, the width and height of the final layer of the joint weld 6 are compared with those of the conventional method on the side of the member 2 to which the end faces are joined. The place to enlarge is also different. That is, in the present invention according to claim 1, on the side of the member 2 to which the end faces are joined, the position 6T of the front-side weld bead toe is changed from the position 7 of the welding root part on the back side to the base material thickness t of 2A. Desirably more than 80% away from the 2A base metal plate thickness t, 1.5t away, ie 6B ≧ 0.8t in FIG. 5 and preferably t ≦ 6B ≦ 1.5t. And at least 10% of the plate thickness t is ensured that the height of the surfacing bead in the entire area of the weld bead width on the back surface and the surfacing height 6H of the front bead in the back surface welding root portion are secured. Desirably, 15% or more and 25% or less are secured, and welding is performed so that the surplus of the final layer of the joint weld 6 smoothly changes from the base material surface of the joint weld member 1 to the member 2. Thus, widening and raising the final layer can be achieved by weaving the weld bead of the final layer or increasing the number of passes.
[0023]
According to the experiment, with the thickness of 20 and 30 mm of 400MP and 500MP steel materials, the bending moment of 2B causes the member 2 to have a bending angle of 10 to 30 degrees in the conventional joint as shown in FIG. In the joint shown in FIG. 5 according to the present invention, cracks were not generated even when bent at 60 ° or more, although cracks occurred in the root portion. Further, when the method according to the first aspect of the present invention is similarly applied to the joint using the back surface overlaying method of FIG. 23, the member 2 is cracked even when almost bent to 90 degrees by the bending moment of 2B. Did not occur. In any of these bending tests, the bent portion was the base material portion. In addition, when the same steel material was used and the tensile load 2C was applied by the method according to the present invention shown in FIG. 5, both of them were broken by the base material, but most of the joints of the conventional method shown in FIG. Cracking or rupture occurred. For the conventional joint as shown in FIG. 4, if the method according to the present invention as shown in FIG. 6 is applied, the same improvement in bending ductility and breakage of the base material against the tensile load were obtained.
[0024]
In the method according to the first aspect of the present invention, when one-side welding is performed at a butt joint in which two members to be joined are substantially in the same plane, as shown in FIG. 19 , a joint formed by a square steel pipe 11 and a diaphragm 12 in advance is used. 16 to FIG. 18 is manufactured by the process of the backside overlay welding method from FIG. 16 to FIG. 18 , and the final layer is wiped with a butt weld joint using a backing metal according to the conventional method of the diaphragm 12 and the flange 2 as shown in FIG. Alternatively, the final layer of the welded joint is welded with t ≦ 6B ≦ 1.5t after finishing with multiple passes, and at least the surface bead surplus height in the region of the weld bead width on the back surface is ensured to be 15% or more and 25% or less. It is possible to apply as Further, when the one-side welding in butt joint the two members is substantially the same plane which Joint produced a are bonded as shown in FIG. 19, the arc heat, as in FIG. 8 or FIG. 9 also croton 10 2. Applying a backing material such as copper that does not melt, overlay welding on the flange back surface in advance and performing groove welding including the weld overlay, and performing joint welding. As shown in FIG. 20 , the final weld layer is welded with t ≦ 6B ≦ 1.5t, and the surplus height of the front bead at least in the region of the weld bead width on the back surface is 15% or more and 25% or less. It was possible to carry out non-scallop welding 27A.
[0025]
In addition, the construction method according to the present invention reduces the stress concentration and improves the bending ductility and the strength of the joint even with a conventional T-shaped joint with a backing metal that causes stress concentration. It is also useful for improving bending ductility and joint strength.
[0026]
【The invention's effect】
The effect by this invention is as follows compared with the conventional method.
1 Claim 1 reduces stress concentration even for a conventional T-shaped joint with a backing metal that causes stress concentration, and improves bending ductility and joint strength. Therefore, it is useful for improvement of bending ductility and joint strength in application to existing steel structures.
2 Regarding claim 1, the buckling strength of the beam is high compared to the dog bone method in which a part of the flange portion of the beam near the building steel joint column-beam joint is cut out, and the manufacturing cost and manufacturing period can be kept low. it can.
[Brief description of the drawings]
1 is an example of a cross-sectional view of a conventional joint shape before one-side welding is performed. FIG. 2 is an example of a cross-sectional view of a conventional joint after one-side welding is performed. Cross-sectional view of the conventional joint surplus shape specification without attachment welding [Fig. 4] Cross-sectional view of the conventional joint surplus shape specification with temporary welding on the backing metal according to the Architectural Institute of Japan specification [Figure 4] 5] Cross-sectional view of the final layer surfacing shape according to the present invention for a conventional joint without tack welding on the backing metal. [Fig. 6] According to the present invention for a conventional joint with tack welding on the backing metal. Sectional view of final layer surplus shape [FIG. 7] Cross-sectional view of application example of surplus shape improvement according to the present invention in butt welding of beam-through-part diaphragm and beam flange [FIG. 8] T-shaped welded joint Applying a non-melting backing material, such as copper, to the back side of the end part of the member to which the end face is welded, and overlay welding was performed on the back side of the end part Plane view and FIG. 9 is an external view of a backing material such as copper which does not melt at arc heat in the longitudinal direction of the end back side, such as H-beams flange was applied to surround the flange end,
[10] The backing material such as copper which does not melt at arc heat in the longitudinal direction of the end back side, such as H-shaped steel flange, against to surround the flange end, appearance was overlay welding view 11 A cross-sectional view showing a one-side welding method in which build-up welding is performed in advance on the back surface of a joint joint portion on the surface of a member such as a diaphragm of a T joint, and both members of the T joint are welded from one side.
FIG. 12 is a one-side welding method in which build-up welding is performed on both the back surface of a joint portion to be bonded on the surface of a member such as a diaphragm of a T joint and the back surface of a joint end surface portion that has been subjected to groove processing, FIG.
[Fig. 13 ] Example of installation of steel end tab by conventional method of column beam joint [Fig. 14 ] Example of column / diaphragm and diaphragm / beam welded part of building joint of conventional method [Fig. 15 ] Water cooling at the end of member Or an example of a cross-sectional view of overlay welding by applying a non-water-cooled copper mold. [FIG. 16 ] A cross-sectional view of a state in which the end of the member and the build-up weld are both grooved and welded to the end of the member. 2 15 and upside down on the display.
FIG. 17 is a cross-sectional view of a state in which the end of the member is overlaid and grooved and applied to the mating member. FIG. 18 is a cross section of the end of the member in a state of being overlaid and grooved and applied to the mating member. [Fig. 19 ] Cross-sectional view of a steel welded joint where a square steel pipe is welded to a diaphragm [Fig. 20 ] Architectural work when overlay welding is performed on the back of the end of the square steel pipe and the flange end of the H-shaped steel end Examples of non-scalloped welds of columns / diaphragms and diaphragms / beams in the mouth [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Joining welding member, for example, a building steel column, a joint diaphragm, etc. 1A Effective throat thickness of joint welding 6 1R Root part corner 2 on the side of member 1 Welding member 2A Plate thickness t and throat thickness 2B of joint welding in FIG. 2 Upward load or bending moment 2C Tensile force 2D Dimension 2E from bottom surface position to 2K of member 2 Groove machining position 2F Groove surface 2G T-type welded joint member T-shaped weld groove gap 2R at the back surface position 2R Root portion corner 2K on the member 2 side Upper end corner portion 2L of the member 2 Lower end corner portion 2M of the member 2 Size 2T T weld joint from the bottom surface position of the member 2 to 2L End face 2U before groove processing of member 2 Bottom surface position 2V of member 2 Groove angle 2Y formed by the bent surface 3 Curved portion 3 of member 2 Back metal 4 Temporary welding of back metal 4A Temporary attachment of back metal Weld toe 5 Groove 6 Joint welding 6A Back bead width 6B Distance from back bead root part or temporary tacking end part to front bead toe part 6H Surplus of front bead toe part at back surface welding root part or temporary tacking end part Height 6T Front bead final layer toe 7 Stress concentrating part 7A due to notch of root part on end face member side of T joint Stress concentrating part 8 due to notch of root part on surface side of T joint 8 Back not melted by welding heat source This material, that is, non-melting type backing material. For example, a water-cooled or non-water-cooled copper backing metal, or a carbon plate 9 overlay welding 9B root portion 10 a groove processing surface 11 in which a joint end face member and an overlay welding portion are both groove-processed 11 a square pipe column 12 a diaphragm 13 Overlay welding 13A constructed on the surface side of the T joint member Overlay welding 14 constructed on the end member side surface of the T joint 27A Non-scallop welding planned portion 28 Scallop 28A Column / web scallop welding

Claims (1)

In the steel structure, when put one member end surface to another member surface undergo a unilateral welding at substantially a right angle to become butt welded joint of T-shaped, the member side end surface is Ru are bonded to beveling, the front side of the The front bead margin is welded so that the position of the weld bead toe is 80% or more of the plate thickness away from the position of the weld root or temporary tack end on the back and at least the area of the weld bead width on the back In a butt joint in which the height is at least 10% of the plate thickness and welding is performed so that the surplus changes smoothly from the surface of the base material, or the two members to be joined are substantially in the same plane When performing single-sided welding, the position of the front end of the weld bead at the front side is at least 80% of the thickness of the weld root part or the end of the back surface on at least the thin side of the two members. You Method for performing welding as welding to and at least the back side of the weld table bead excess Sheng height in the region of the bead width is secured thickness of more than 10% excess Sheng changes smoothly from the base metal surface such.

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