十字双拼角钢柱绕虚轴弯曲屈曲临界力计算方法精度对比

ACCURACY COMPARISON OF DIFFERENT METHODS FOR BUCKLING CRITICAL FORCE ABOUT VISUAL AXIS OF DOUBLE STAR-BATTENED COLUMNS

数值分析和构件试验均表明:按实腹式计算方法设计的双拼角钢柱受压承载力明显偏于不安全,应按组合构件计算。当按组合式构件计算方法设计该柱时,各种文献给出的绕虚轴弯曲屈曲临界力的简化计算方法并不一致,有必要根据有限元计算结果校核以上算法的精度,为双拼角钢柱的设计研究工作提供参考。首先列举了3种常见的双拼角钢绕虚轴屈曲临界力的计算方法及原理,然后采用壳单元离散双拼角钢柱,采用ANSYS的线性屈曲模块,计算其屈曲临界力。最后,对比有限元和以上3种算法的计算结果,表明:GB 50017—2003《钢结构设计规范》或ANSI/AISC 360-05《Specification for Structural Steel Buildings》中缀板柱的计算式误差相对较小,推荐使用。

Results from experiments and numerical models all showed that the compressive strength of the double star- battened columns designed as a plain web column according to the current codes is unsafe obviously. If they are designed as built-up columns, different simplified methods given in codes are not unified to calculate the critical buckling force, so it is essential to compare the accuracy of the methods by numerical models to give references for design or research. Therefore, firstly 3 simplied methods to determine the critical buckling force of the star-battened columns were described, then the star battened columns are simulated by shell elements and their critical buckling forces were given by ANSYS. Finally, the results from the simplified methods and the numerical model were compared, which showed that the method for the battened column given by Chinese Code for Design of Steel Structures （ GB 50017--2003 ） or USA Specification for Structural Steel Buildings （ANSI/AISC 360 -05 ） is more accurate than other mehods, and it can be recommended to be used for desigh.