鋼構造建築部材の高温時限界耐力解析と設計用評価法

摘要

Limit-state strengths of I-shaped structural steel members at elevated temperatures are analytically investigated by using detailed finite shell element models. Elastic and inelastic flexural buckling and lateral-torsional buckling are simulated for the limit-states of columns and unbraced beams, respectively. The simulations are conducted using steel design properties at elevated temperatures described in Recommendation for Fire Resistant Design of Steel Structures and Eurocode 3, which are compared with existing test data by several researchers. Pursuing realistic and practical evaluation of structural performance, equations for column and unbraced beam strengths are proposed as functions of elevated temperatures and member length. The proposed strengths agree well with the simulation data using the steel properties from Eurocode 3, which are more representative of the test data. This member-based strength evaluation is expected for use as an alternative simple design approach for future limit-state design in structural fire engineering.%性能設計の時代を迎えて，耐火建築構造工学の分野においても， 建築設計者が構造物の耐火性能をより正確に評価することにより建 築主や社会に対して説明責任を果たし，より安全で自由な設計を実 現する動きが世界各国で広まりつつある。そのような動きの1つと して，設計規準や指針などの整備がある。火災時の建築構造物の挙 動は複雑で不確定な要素が多く，研究で解明されていない現象も多 い上，数値解析には高度な技術が必要である。