黄占飞的转动约束和轴向约束对约束柱的朗肯理论.pdf

Journal of Constructional Steel Research 59 (2003) 1553–1571 /locate/jcsr Rankine approach for fire resistance of axially- and-flexurally restrained steel columns Zhan-Fei Huang , Kang-Hai Tan Nanyang Technological University, School of Civil and Environmental Engineering, 50 Nanyang Avenue, Singapore 639798, Singapore Received 12 June 2002; received in revised form 22 June 2003; accepted 26 June 2003 Abstract Traditionally, the Rankine equation has been applied to investigate the load bearing capa- cities of steel columns or frames at room temperature. Recently, the method has been ex- tended to predict the fire resistance of a simply supported steel column by taking the temperature effects on steel material into consideration. This paper further extends the Rankine equation to predict the fire resistance of an isolated steel column from the sur- rounding structure. The complicated boundary restraints contributed by the adjoining struc- ture are represented by a linear spring and a pair of rotational springs attached to the column ends. Both the boundary restraints and creep strain are incorporated into the Ran- kine equation. The predictions of Rankine approach are verified experimentally and numeri- cally. Generally, it is shown that under different external load utilization factors and boundary restraint levels, Rankine approach yields accurate and slightly conservative predic- tions. # 2003 Elsevier Ltd. All rights reserved. Keywords: Rankine approach; Steel column; Critical temperature; Axial restraint; Flexural restraint; Creep 1. Introduction About a century ago, Rankine [1] proposed his famous empirical formula for load bea