Formulation of Load Deflection Relations of Steel Concrete Composite Columns

本文旨在建立钢管混凝土柱的局部屈曲极限、收缩极限、裂缝发生极限和初始屈服极限的荷载-位移关系。对于钢管混凝土柱，Tsuda研究了钢管混凝土柱的经验侧移角与残余侧移角的关系。结果表明：1)随着轴压比的增大，残余偏角增大；2)与轴压比相比，宽厚比和径厚比对残余偏角的影响不明显；3)轴压比较大时，柱达到收缩极限后，残余偏角变大。以收缩极限、局部屈曲极限和强度保证极限为判据，考察了宽厚比、径厚比和轴压比的影响。Fujinaga和Tsuda通过已有的试验和数值分析，研究了钢管混凝土梁柱的循环性能和单调性能之间的关系。在小挠度阶段，单调行为对应于循环行为的包络曲线，而在大挠度阶段，单调行为对应于循环行为的累积曲线。对于型钢混凝土梁，Sakai和Lee进行了试验，选择了外包含钢率和板的存在作为试验参数。酒井检视了荷载偏转关系。

The objective of this study is to formulate the load-displacement relationship which can evaluate the local buckling limit, shrinkage limit in case of CFT columns, crack occurrence limit and initial yield limit in case of SRC columns and beams.As to the concrete filled columns, Tsuda investigated relation between experienced lateral drift angle and residual one of concrete filled steel tubular columns. As the results, 1) residual drift angle becomes large as the axial load ratio of the column becomes large, 2)the effect of width-thickness ratio and diameter-thickness ratio on the residual drift angle is not apparent, comparing with the axial load ratio, 3) in specimens with high axial load ratio, the residual drift angle becomes large after the column attained the shrinkage limit.Moreover, accumulated plastic angles are calculated using previously performed test. As the criterion, shrinkage limit, local bucking limit, strength assurance limit are selected, and effect of width-thickness ratio, diameter-thickness ratio and axial load ratio are examined.Fujinaga and Tsuda investigated the relations between cyclic and monotonic behavior on CFT beam-columns by using the previously performed experiment and numeric analysis. While in the small deflection stage, monotonic behavior correspond to envelop curve of cyclic behavior, in the large deflection stage, monotonic behavior correspond to accumulated curve of cyclic one.As to SRC beam, Sakai and Lee performed experimental test, selecting the encased steel ratio and existence of slab as the test parameters. Sakai examined the load deflection relationship.