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CN-122003308-A - Welded joint and method for manufacturing same

CN122003308ACN 122003308 ACN122003308 ACN 122003308ACN-122003308-A

Abstract

The invention provides a welded joint of a floating body type offshore wind power generation device comprising a tower member, a floating body member and a bracket, wherein a weld bead is extended to the floating body member, thereby improving fatigue strength of a welded portion. The welded joint of the present invention has a first bead, a second bead, and a third bead, the first bead being formed along one short side of a rectangular abutment surface where a bracket abuts against a float member, the second bead and the third bead being formed along two long sides of the rectangular abutment surface, and being formed so as to extend onto the float member so as to cover either a start end or a termination end of the first bead. Further, it is preferable that M/N, which is a ratio of a distance M between the distal end portion of the second bead and the distal end portion of the third bead to a length N of the extension portion of the second bead or the third bead, is 2.0 or less.

Inventors

  • TAKAGI YOSHIFUMI
  • SAKIMOTO TAKAHIRO
  • HANDA TSUNEHISA

Assignees

  • 杰富意钢铁株式会社

Dates

Publication Date
20260508
Application Date
20241015
Priority Date
20231020

Claims (10)

  1. 1. A welded joint comprising a first member, a second member abutting against a surface of the first member, and a support member contacting the first member and the second member, The weld joint has a first weld bead, a second weld bead, and a third weld bead, The first bead is formed along one short side of a first rectangular abutment surface where the support member abuts the first member, The second bead and the third bead are formed along each long side of the first rectangular abutment surface, and are formed so as to extend onto the first member so as to cover either a start end or a termination end of the first bead.
  2. 2. The welded joint according to claim 1, wherein M/N representing a ratio of a distance M between a leading end portion of the second bead and a leading end portion of the third bead to a length N of the extension portion of the second bead or the extension portion of the third bead is 2.0 or less.
  3. 3. The welded joint according to claim 1 or 2, wherein a length N of the extension of the second bead and the extension of the third bead is in a range of 4.0mm to 60.0 mm.
  4. 4. The welded joint according to claim 1 or 2, wherein the welded joint further has a fourth weld bead formed along long and short sides of a second rectangular abutment surface where the support member abuts the second member.
  5. 5. The welded joint according to claim 1 or 2, wherein the welded joint is used as a welded joint of a floating body offshore wind power plant, The first member is a floating body member, the second member is a tower member, and the support member is a bracket.
  6. 6. A method for manufacturing a welded joint comprising a first member, a second member abutting against a surface of the first member, and a support member contacting the first member and the second member, The weld joint has a first weld bead, a second weld bead, and a third weld bead, The first weld bead is formed along one short side of a first rectangular abutment surface where the support member abuts the first member, The second bead and the third bead are formed to extend along each long side of the first rectangular contact surface and onto the first member so as to cover any one of the start end and the end of the first bead.
  7. 7. The method for producing a welded joint according to claim 6, wherein M/N, which is a ratio of a distance M between a distal end portion of the second bead and a distal end portion of the third bead to a length N of the extension portion of the second bead or the extension portion of the third bead, is 2.0 or less.
  8. 8. The method for producing a welded joint according to claim 6 or 7, wherein a length N of the extension portion of the second bead and the extension portion of the third bead is in a range of 4.0mm to 60.0 mm.
  9. 9. The method for manufacturing a welded joint according to claim 6 or 7, wherein the welded joint further has a fourth bead, And forming a fourth welding bead along the long side and the short side of a second rectangular abutting surface of the supporting member abutting against the second member.
  10. 10. The method for manufacturing a welded joint according to claim 6 or 7, wherein the welded joint is used as a welded joint of a floating body offshore wind power generation device, The first member is a floating body member, the second member is a tower member, and the support member is a bracket.

Description

Welded joint and method for manufacturing same Technical Field The present invention relates to a welded joint and a method for manufacturing the same, and more particularly, to a welded joint which has excellent fatigue strength by performing gas shielded arc welding on a floating body member or the like via a bracket, such as a welded joint portion of a floating body type offshore wind turbine generator, and a method for manufacturing the same. Background In recent years, in the field of offshore wind power generation, floating offshore wind power generation has been studied because it is easy to install even in a sea area having a water depth of 50m or more. Since floating offshore wind turbine generators are exposed to external forces such as waves, the problem of improving the fatigue life of the toe portion of the welded joint of these devices is to be studied. Accordingly, various studies have been made on a technique for improving the fatigue strength of a welded joint portion of a large-sized structure such as an offshore wind turbine generator. For example, patent document 1 discloses a welded beam structure comprising a rib and a panel, wherein both sides of an end portion of the rib are attached to a structural member by fillet welding, respectively, to form a pair of extended beads with the structural member, and the extended beads are formed by slightly extending the fillet welded bead on the structural member. Patent document 1 also discloses that the panels are attached to both sides of the side edges of the ribs by fillet welding, respectively, and a pair of extended beads with the ribs are formed, and the extended beads are formed by slightly extending the fillet welded beads on both sides of the side edges of the ribs. It is said that by these extended beads, fatigue crack generation from the weld toe can be suppressed. Patent document 2 discloses a weld bead structure including two side weld beads formed by fillet welding on both sides of one plate while facing an end face of the other plate, and two side extension weld beads formed by extending welding the two side weld beads from an end of the other plate to one face. Patent document 2 also describes that an end bead formed by additionally welding an end of one plate and an end of the other plate is provided between the extended beads on both sides. This makes the toe away from the high-stress portion where defects are likely to occur in the weld bead, thereby improving the durability of the welded portion. Further, patent document 3 discloses a welded joint, which is a lap welded joint between a gusset and a main plate, and has a first bead extending from both sides of the short side of the gusset to the main plate, and second and third beads extending to the main plate along the long side of the gusset while covering the first bead. It is said that a wire-wound welded joint which can improve fatigue strength at low cost and stably can be obtained. Prior art literature Patent literature Patent document 1 Japanese patent laid-open No. 8-155634 Patent document 2 Japanese patent laid-open No. 9-253843 Patent document 3 Japanese patent application laid-open No. 2018-158380 Disclosure of Invention Problems to be solved by the invention The methods described in the above patent documents are said to be effective for improving the fatigue strength of the welded joint. However, it is not clear whether the fatigue strength of a welded joint portion of a large-sized structure such as an offshore wind turbine is improved by adding a structural stress concentration to a welded joint portion of a tower portion, a floating body portion, a bracket, or the like of a floating body type offshore wind turbine in addition to a local stress concentration. Accordingly, the present inventors have searched for a method for improving the fatigue strength of a welded joint of a floating offshore wind turbine generator in which structural stress concentration is superimposed in addition to local stress concentration. As a result, it was found that by controlling the shape and arrangement of the weld beads, fatigue strength can be improved. The present invention is directed to solving the problems of the prior art, and relates to a welded joint of a large-sized structure, for example, a welded joint of a floating body type offshore wind turbine generator including a tower member, a floating body member, and a bracket, wherein a weld bead is extended to the floating body member. Accordingly, an object of the present invention is to provide a welded joint having improved fatigue strength and a method for manufacturing the same. Means for solving the problems In order to achieve the above object, the present inventors have first fabricated a dummy structure that simulates a welded joint of an actual structure of a floating offshore wind turbine. As the welded joint of the simulated structure, a welded joint in which fillet welding was performed along the member as