Q345大规格角钢轴压试验及失稳形态分析

Experimental study of Q345large-section angle steels andanalysis of buckling mode under axial compression

大规格高强度角钢现已被广泛应用于我国的特高压输电线路工程.研究表明,采用此类构件可大幅提高构件的承载力,经济效益明显,但目前对于其较高承载力的来源尚缺乏深入研究.对此,本文以肢宽为250 mm、肢厚为28 mm、长细比为30~60的12根Q345材质的大规格角钢构件为研究对象,进行了系统性的轴压试验.通过对各试件的失稳形态进行统计,并结合我国现行规范,对试验现象及结果进行了分析.结果表明:此类构件的失稳形态以弯曲失稳为主,且局部稳定性较好;由于壁厚较大,存在截面次翘曲扇形惯性矩I■,提高了构件的抗扭刚度;截面次翘曲扇形惯性矩I■对换算长细比的影响,在小长细比试件中更为明显.

The high strength and large-section angle steels(HLS)have been used widely in UHV transmission engineering.The researches show that the bearing capacity and economy of member with HLS can be improved considerably.However,the source of the high bearing capacity of HLS lacks.In light of the above-mentioned situation,an axial compression column test was conducted to investigate the bearing capacity of large-section angle steels including 12large-section angle steel elements that the limb width is 250mm,limb thickness is 28mm and 4different slenderness ratios.Through the statistical analysis of the buckling modes of every specimen,combined with current norms,the phenomena and results of the test were analyzed.It is shown that the buckling modes are mainly bending-buckling;and the localnsi stability of specimens meets requirement.Besides,because of the thick section,the sectional secondary warping inertia which improves the torsional rigidity of specimen cannot be neglected.Meanwhile,the effect of the sectional secondary warping inertia on the equivalent slenderness ratio is more obvious in stub columns.