Detailed examination on steel strain rate for steel structures subjected to fire and developments of upgrading of fire resistant design
| Project/Area Number |
18K04429
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Review Section |
Basic Section 23010:Building structures and materials-related
|
|---|
| Research Institution | Nagoya University |
|---|
Principal Investigator |
Ozaki Fuminobu 名古屋大学, 環境学研究科, 准教授 (40434039)
|
|---|
| Project Period (FY) |
2018-04-01 – 2021-03-31
|
| Project Status |
Completed (Fiscal Year 2020)
|
| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2020: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2019: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2018: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
|
|---|
| Keywords | 耐火 / 鋼構造 / ひずみ速度 / 高温曲げ実験 / 高温座屈実験 / 高温曲げ強度 / 高温座屈耐力 / 崩壊温度 / 鋼材ひずみ速度 / 加熱速度 / 載荷重速度 / 鋼構造耐火 / 高温座屈 / 建築構造 |
|---|
| Outline of Final Research Achievements |
The bending strength, flexural buckling strength, and collapse temperature of steel members were examined by steady and transient state tests with various heating and deformation rates to clarify relationships between those fire resistance and steel strain rate. The stress-strain relationships for mild steels at elevated temperatures were obtained by coupon tests under three strain rates. A bending test using a beam specimen was conducted to examine the effects of the deformation rates under steady-state conditions and the heating rates under transient state conditions. Flexural buckling tests were conducted under steady-state and transient-state conditions. It was clarified that the bending strength and collapse temperature are evaluated by the full plastic moment using the effective strength under fast strain rates. The flexural buckling strength and collapse temperature are approximately evaluated by the buckling strength using 0.002-offset yield strength under a slow strain rate.
|
| Academic Significance and Societal Importance of the Research Achievements |
本研究でひずみ速度の実態が解明されることで、現行高温素材試験の画一的なひずみ速度設定値が持つ工学的意味と問題点を明らかにし、建築耐火向けの新試験法の提案を目指した。高温曲げ強度はひずみ速度が大きな場合(3or7％/min.)のひずみ2％時応力の有効降伏強度、高温全体座屈はひすみ速度が小さな場合(0.3％/min.)の0.2％offset耐力で評価可能であることが分かった。通常試験のひずみ速度は全体座屈評価に、一方、試験途中でひずみ速度を上昇させた鋼材強度は高温曲げ強度に対応可能で、現行の素材試験結果を活用し、試験途中にひずみ速度を意図的に上げるという新試験法で、梁と柱の高温強度が評価できる。
|
Report
(4 results)
Research Products
(18 results)
