基于截面分类的U形钢-混凝土组合梁外包钢板件宽厚比限值
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中图分类号：TU375 文献标志码：A 文章编号：2096-6717（2025）04-0066-12
Width-thickness ratio limit of outer steel plate of steel-concrete composite beam with U-section based on section classification
CHENG Rurb， YU Yuanlina，ZHANG Jiayu²， ZHANG Qingfenga （a. Schoolof Civil Enginering; b.Key Laboratory of New Technology for Construction of Cities in Mountain Area， Ministry of Education，Chongqing University，Chongqing 40oo45，P.R. China）
Abstract： In order to study the plate width-thickness ratio limits of steel palte based on section classification for Steel-Concrete Composite Beam with U-section （SCBU），monotonic static loading tests were conducted on five TSCU specimens. The damage modes，load-displacement curves and plastic deformation capacities of SCBU with different combinations ofheight-thicknessratios of outer steel-ncased web in compressionarea and widththickness ratios of compressed flange were analyzed.The testing results show that the width-thickness ratio of the steel plate has a direct influence on the buckling deformation and plastic deformation capacity of the SCBU. All the specimens sufered local buckling before reaching the peak bearing capacity，the failure mode was bending plastic damage.Meanwhile，the finite element analysis results show that the nonlinear behavior between the steel plate web and compressed flange interacts with each other，the buckling moment of the plate advances with the increase of width-thickness ratio of the adjacent plate，and the degree of plastic development of the SCBU decreases with the increase of width-thickness ratio of stel plate.Based on the results of the test and finite element parametric analysis，the recommended limit value of width-thickness ratio for class II section （Class 2）steel palte of SCBU is proposed，and the proposed limit is compared and analyzed with the code limit， and theresults show that this limit value is more consistent with the real force performance of the SCBU and could give fuller play to its structural advantages to a certain extent.
Keywords： steel-concrete composite beam with U-section （SCBU）；section classification；width-thickness ratio；experimental study；finite element analysis
U形钢-混凝土组合梁（U形钢组合梁）外包钢对内部填充混凝土有较强的变形约束作用，能提高后者的抗压强度，同时，内部填充混凝土能有效抑制外包钢的内屈变形，使外包钢局部屈曲半波由3个变为1个，提高了U形钢组合梁的整体稳定性、抗弯承载力和塑性发展程度[1]。（剩余15875字）
