PBL加勁型矩形鋼管混凝土軸壓柱局部屈曲性能分析

張寧+劉永健+李慧

摘要：為研究開孔鋼板連接件（PBL）加勁肋對矩形鋼管混凝土軸壓柱局部屈曲性能的影響，用能量法推導(dǎo)鋼管屈曲系數(shù)計算公式，引入PBL和加勁肋相對剛度計算式并分析二者對屈曲模式的相互作用關(guān)系，討論了PBL加勁型鋼管的極限屈曲模式及其極限屈曲系數(shù)、最大相對寬厚比限值。結(jié)果表明：PBL加勁肋可明顯改善鋼管局部穩(wěn)定性，鋼管屈曲系數(shù)k隨著PBL加勁肋剛度增加而增大，直至達(dá)到極限屈曲系數(shù)42.68；PBL連接件可減小板件縱向屈曲的波長，而加勁肋的影響作用與之相反；設(shè)置PBL加勁肋后，鋼管的最大相對寬厚比限值可達(dá)184，并且板件屈曲后強(qiáng)度隨寬厚比的變化曲線下降趨勢減緩，強(qiáng)度值隨著PBL剛度增加而逐漸提高。

關(guān)鍵詞：PBL加勁肋；矩形鋼管混凝土；局部屈曲；能量法；臨界屈曲系數(shù)

中圖分類號：TU375 文獻(xiàn)標(biāo)志碼：A

文章編號：1673-2049（2017）02-0095-08

Abstract：In order to study the effects of PBL stiffener on the local buckling performance of rectangular concrete-filled steel tubular axial compression columns， the calculation formula for buckling coefficient of steel tube was deduced by energy method. The relative stiffness formulas of PBL and stiffener were introduced and the interactions between the two models and buckling modes were analyzed. The ultimate buckling modes and the critical buckling coefficient， the maximum relative width to thickness ratio of PBL steel tube were discussed. The results show that PBL stiffener can improve the local stability of steel tube. The buckling coefficient k increases with the increase of the stiffness of PBL rib until the ultimate buckling coefficient reaches 42.68. The PBL connector can reduce the longitudinal buckling wave length of the plate， and the effect of the stiffener rib is opposite. The maximum relative width to thickness ratio of the steel tube can reach 184 after setting PBL stiffener. The curve change trend of the plate strength with the width to thickness ratio decreases after buckling， and the strength increases gradually with the increase of PBL stiffness.

Key words：PBL stiffener rib； rectangular concrete-filled steel tube； local buckling； energy method； critical buckling coefficient