基于材料性能退化的非对称截面单阶钢柱滞回性能研究

RESEARCH ON THE HYSTERETIC PERFORMANCE OF ASYMMETRICAL CROSS-SECTION STEEL SINGLE-STEP COLUMN BASED ON THE MATERIAL PERFORMANCE DEGRADATION

考虑局部锈蚀区域截面损失和材料性能退化,借助ABAQUS对非对称截面单阶柱进行低周反复性能非线性分析,得到常轴力、反复水平荷载作用下,不同锈蚀部位、不同锈蚀深度单阶柱的滞回性能变化规律。结果表明,锈蚀深度D变化的影响为:腹板D>4 mm,翼缘和腹板同时锈蚀D>2 mm时,锈蚀越深,材性退化越明显,阶形柱水平极限承载力、抗侧刚度、滞回耗能和延性等降低较大;翼缘D≤5 mm、腹板D≤4 mm、翼缘和腹板同时锈蚀D≤2 mm时,随着D的增加,滞回性能各指标均有所降低,但变化幅度不明显,对阶形柱恢复力特性影响小;因阶形柱下柱两分肢截面不对称、偏心荷载及荷载-位移(P-Δ)效应,使构件在反向加载时延性劣化突出。

Considering the local corrosion area section loss and material performance degradation,the analysis of lowcyclic loading nonlinear properties of asymmetrical cross-section steel single-step column was carried out by using the finite element analysis software ABAQUS,the change rule of single-step column hysteretic properties in different corrosion parts and corrosion depth under the action of constant axial force,horizontal load was obtained. The results showed that： when the web corrosion depth D 〉4 mm,web and flange at the same time corrosion depth D 〉2 mm,the deeper the corrosion depth was,the more obvious the material property degradation was,the horizontal ultimate bearing capacity,lateral stiffness,hysteretic energy dissipation and ductility of the column were greatly reduced; when the flange corrosion depth D≤5 mm、the web corrosion depth D ≤ 4 mm,web and flange at the same time corrosion depth D ≤2 mm,with the increase of D,all indexes of the hysteretic performance were reduced,but the change was not obvious,had a minor effect on the restoring force characteristics of single-step column; because of the asymmetry of cross section of the lower column,eccentric loading and P-Δ effect,the ductility degradation was outstanding in reverse loading.