大规格Q420高强度角钢构件轴压力学性能试验研究

Experimental research on mechanical behavior of large-section and Q420 high-strength angle members under axial compression

钢材强度等级为Q420及以上、肢宽为220 mm和250 mm的大规格高强度角钢构件已在输电铁塔中得到应用,然而目前对大角钢构件轴压力学性能的研究有待深入。为研究此类角钢构件的轴压力学性能,对强度等级为Q420的6种截面规格、5种长细比的90根大规格角钢构件进行了轴压试验研究。基于试验结果,研究了大规格角钢构件在轴心压力作用下的失稳形态和极限承载能力,计算了各试件的稳定系数,并与多部规范中的柱子曲线进行对比分析。结果表明:大规格角钢轴压构件的失稳形态以弯曲失稳为主;试验得到的稳定系数明显超过现行规范给出的柱子曲线,现行规范中对该类轴压构件的计算偏于保守。

Large-section and high-strength angles( big angles),which are construction members with nominal strength higher than or equal to 420 MPa,limb width of 220 mm or 250 mm,have begun to be used in the field of steel transmission towers. However the mechanical behavior of such angles has been rarely known by now. To investigate the mechanical properties of such steel members,axial compression column tests was conducted. There were six types of sections and five different slenderness ratios of Q420 big angle member included in the tests,and the total number of the specimens was 90. Based on the test results,the buckling modes and the ultimate strength under axial compression of these specimens were analyzed. And the stability coefficients of these specimens were calculated,which were compared with column curves from different codes. It is shown that,the buckling modes are mainly bending-buckling, and the stability coefficients calculated according to axial compression tests are higher than those from the different codes. Design methods in current codes are conservative for such kind of steel members.