新型冷弯翼缘闭合组合构件轴压力学性能

为探讨进一步优化使用冷弯薄壁型钢材料,利用冷弯薄壁型钢截面成型灵活的特点,将既有的两类翼缘闭合截面形式经过合理变形,再经组合点焊形成两类新型截面形式——翼缘闭合组合截面DHF1、DHF2.采用ANSYS非线性有限元分析方法,针对新型截面轴压构件,建立了有效的分析模型,通过对构件的应力-应变关系曲线、参数变化时的极限应力变化曲线和应力、变形云图,全面考察了截面高度、截面宽度、板件厚度和闭合区高度比等参数对构件的变形模式、屈曲特征、承载力、极限应力等方面力学性能的影响规律.研究结果表明,新型截面轴压构件板件的局部屈曲不易出现,从而具有截面刚度大、承载能力强的特点,对于中、小长细比构件的极限应力常可达到材料的屈服强度,证明提出的冷弯翼缘闭合新型组合截面轴压构件具有较为优越的力学性能.

Behaviors of two new kinds of cold-formed flange-closed composite section members under axial compression

To optimize the design of cold-formed section,two new kinds of cold-formed flange-closed composite section are developed. Based on precise finite element model,nonlinear finite element method was adopted to study the static behaviors including buckling modes,deformed process,load-displacement curves and stress-strain curves of these section members under axial compression loads,according to the stress-strain curve and the ultimate stress curve changing with parameters. It can be concluded that the local buckling stress of new sections is enhanced significantly,which strengthens the load capacity and rigidity of members,and the ultimate stress can always reach the yield strength of the steel towards the members with medium or small slenderness ratio. It is proved that the two new types of sections have some superior static behaviors in the experimental study,which indicates that they can be used in the practical engineering.