| Project/Area Number |
63550550
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
溶接工学
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| Research Institution | Osaka University |
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Principal Investigator |
MURAKAWA Hidekazu Osaka Univ., Welding Research Institute Associate Professor, 溶接工学研究所, 助教授 (60166270)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1989: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1988: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | Spot Welding / Initial Gap / Squeezing Deformation / Similarity Rule / Contact Problem / Elastic Plastic Large Deformation Problem / Finite Element Method / Allowable Gap / 接触面積 / 加圧力 / 臨界曲線 / 溶接性 / 力学 / 相似則 / 弾塑性 |
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| Research Abstract |
The process of the spot welding can be divided into the following five stages. (1) from the beginning of the squeezing to the initial contact between plates (workpieces) (2) process in which the contact area between workpieces increases due to the increase of the squeezing force. (3) heating and melting process with the electric current with holding the squeezing force. (4) cooling process with holding the squeezing force. (5) releasing squeezing force
The squeezing processes in the first and the second stages were analyzed by F.E.M. to clarify the effect of the weld joint geometry and material properties upon the squeezing force required to close the initial gap and the contact state. The obtained results were generalized using the mechanical similarity rules. Based on the generalized data, a methods to predict the squeezing force required to close the initial gap were proposed. Further, the precise contact state at the second stage was also analyzed and a method to determine the allowable initial gap was proposed. As for the stages after the second stage, Finite Element Method to solve the axisymmetric thermal-elastic- plastic problems was developed and the mathematical formulation to analyze the heat generation by the electric current were derived.
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