1987 Fiscal Year Final Research Report Summary
Study on non-linear fracture mechanics of welding connections of steel structure
| Project/Area Number |
61550406
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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 |
Building structures/materials
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| Research Institution | Shinshu University |
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Principal Investigator |
NAKAGOMI Tadao Shinshu University, 工学部, 助教授 (60111671)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Welding flaw / Non-linear fracture mechanics / J value / j^^ value / Strain velocity Welded connection / 溶接接合部 / 3次元のJ値 / 3次元のJ値 |
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| Research Abstract |
It is important to investigate the mechanical properties or the behaviors of welded connections in steel structures under large earthquakes which occur once in several decades. We have studied mechanical properties of welded connections or base metals under large deformation, and investigate the required properties of them. Then, the relationship between notch length in welded zone and the required properties was investigated in order to obtain the basic data for deciding limits allowed flow length, and obtained some results as follows.
1) It was confirmed that the transition temperature of fracture toughness under high strain velocity was fairly higher than it under low strain velocity.
2) It became clear that the fracture toughness of welded zone is more important factor than welding flaws or notches of backing strips for the fracture. It was also confirmed that the deformation became remarkably small when high strain velocity was given in case of lower temperature than the transition temperature.
3) In order to deal with three dimensional cracks in fracture mechanics, three dimensional formula was standardized and accuracy of it was examined. Then, It was confirmed that K (stress intensity factor) is equal to J value during elastic range, and J value is almost equal to j^^ value under monotonic loading. Therefore, it became possible to apply j^^ value on three dimensional problems.
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Research Products
(4 results)
