混凝土填充变壁厚矩形钢管的弯曲性能

Flexural Behavior of Concrete Filled Non-Uni-Thickness Walled Rectangular Steel Tube

在纯弯状态下,对3个变壁厚矩形混凝土填充钢管力学性能进行了试验研究,以研究组合梁的弯矩与变形关系。首先,对变壁厚混凝土填充矩形钢管的极限弯曲强度和基于目前设计标准的单一壁厚混凝土填充钢管梁的预测强度进行了比较。提出一非线性有限元模型对试验结果进行验证,用该有限元模型研究了钢管壁厚比对组合梁弯曲强度的影响。试验与分析结果都表明,变壁厚矩形混凝土填充钢管梁具有较好的延性,其弯曲强度高于单一壁厚混凝土填充矩形钢管梁的弯曲强度。

This paper presents an experimental study on the mechanical behavior of non-uni-thickness walled rectangular concrete-filled steel tube （CFT） beams subjected to pure bending. Three specimens were fabricated and tested to investigate the relation of bending moment vs. deflection of the composite beam. First, the ultimate flexural strength of non-uni-thickness walled rectangular CFT is compared to the predicted strength of corresponding uni-thickness walled CFT beams based on current design codes. Then a nonlinear finite element model is developed and verified with experimental results. The FEM model is used to investigate the effect of the steel wall thickness ratio on the bending strength of the composite beam. Both experimental and analytical results suggest that a non-uni-thickness walled rectangular CFT beam exhibits adequate ductility, and the flexural strength of a non-uni-thickness walled CFT beam is superior to that of a uni-thickness wailed CFT beam.