冷成型单角钢轴心受压杆极限强度研究

On the Ultimate Strength of Concentrically Loaded Cold-Formed Angle Members

本文用有限元法对冷成型单角钢压杆的极限承载力进行了研究,分析了截面特性、初曲、弯角硬化、角度大小及杆端约束对轴心受压单角钢杆件极限承载力的影响.给出了L60°-50×3和L90°-50× 3各6根单角钢压杆两端为铰接的轴心受压试验结果。计算数据与我国现行规范GBJ18-87及美国AISI规范进行了比较.理论分析与实验结果符合较好。对长细比不大的压杆,60°角钢因弯扭失稳而承载力较低,用现行规范计算可能偏于不安全.为此,对稳定系数的修正提出了便于应用的折减系数。

In this paper the ultimate strength of cold formed angle members is studied by finite element method.The effects of cross section,initial out-of-straightness,cold-strain hardening,angle of cross section and restraints at the ends of the member on the ultimate loads of concentrically loaded angle members are taken into account.The test results for six of each L60 degree-50×3 and L90 degree-50×3 concentrically loaded single angle members with hinged end condition are presentcd.Experimental failure loads are compared with the theoretical values by using finite element method and also with some current codes such as specification GBJ18—87 and AISI,1986.The theoretical results are satisfactorily conformed to the test ones.Due to torsional flexural buckling, the values of the test strength of concentrically loaded 60 degree angle members in low slenderness are lower than the calculqting values by spercifications GBJ18—87 and AISI,1986.A modified design formula for calculating the coefficients of such kinds of members is suggested.