J-GLOBAL ID:200904023251641071  Research Project code:9800047989 Update date:Dec. 15, 2003

Development of the technology to improve structural safety using next generation steel materials: (2) Analysis of and countermeasures against the breaking phenomenon of steel materials

次世代鋼材による構造安全性向上技術の開発 (2)鋼材の破断現象の解析・対策
Study period:1996 - 1998
Organization (1):
Investigating Researcher (1):
Research overview:
1) Purpose of this study: In the earthquake in the southern part of Hyogo Prefecture in 1995 breaking phenomenon like the breaking of a chalk was seen in steel materials without stretch in super-high-rise buildings and bridge supports. Also in the reinforcing steels of ferroconcrete structures the same phenomenon was seen centering on the joints. In designing a structure using steel materials in architecture and civil engineering a method is adopted in which the structure can resist to normal load or an earthquake of up to a medium scale as much as leaving no transformation (elastic design) and can avoid the collapse by absorbing the energy due to its transformation at the time of a major earthquake (plastic design). But in the earthquake in 1995 the breaking phenomenon occurred without the energy absorption by transformation, which means that collapse is likely to happen by the force smaller than assumed external force. This fact can shake the foundation of the present structural system and it is an extremely important and urgent task to investigate into the causes of this phenomenon, examine the countermeasures and secure the safety of the structures of steel materials. Even the occurrence mechanism of the phenomenon is unknown and in order to reveal the causes comprehensive analysis, research and development are necessary for material properties, influence of construction, effect of design and etc. 2) Study Plan: (2) Analysis of and countermeasures against the breaking phenomenon of steel materials (a) Analysis of and countermeasures against the behaviors of steel materials caused by impact force: We analyze by experiments the behaviors such as destruction mechanism caused by repeated impact load and examine the countermeasures. (b) Analysis of and countermeasures against the influences of welding of steel materials: We analyze by experiments the cause and effect of the destruction of welded joints by the influences of the welding of steel materials and examine the countermeasures.
Research program: Assistance of Research and Development of Construction Technology
Ministry with control over the research :
Ministry of Land, Infrastructure, Transport and Tourism
Research budget: 1998: \25,029,000

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