内置CFRP管的方钢管混凝土轴压短柱失效分析及延性优化

Failure Analysis and Ductility Optimization of CFSST Stub Column with Inner CFRP Tube Under Axial Compressive Load

为了分析内置CFRP管(碳纤维增强塑料圆管)的方钢管混凝土轴压短柱失效原因,并探索延性优化的方法,基于相关试验的文献资料,采用有限元方法对轴压短柱工况进行计算,并结合试件剖析失效的原因。采用麦夸特法回归分析,提出内置CFRP管的方钢管混凝土柱延性优化初探计算式。结果表明:CFRP管破裂是内置CFRP管的方钢管混凝土轴压短柱最终失效的主要原因;内置CFRP管的方钢管混凝土轴压短柱的核心混凝土裂缝开展较普通方钢管混凝土范围更小;CFRP管粘结长度不足,会导致内置CFRP管的方钢管混凝土轴压短柱无法充分发挥力学性能。适当提高碳钢约束比ξf/ξs,可以改善和优化内置CFRP管的方钢管混凝土轴压短柱的延性性能。

In order to analyze the failure and optimize the ductility of concrete-filled square steel tubular stub column with inner CFRP tube （CFSST-CFRP） under axial compressive load, the mechanical behaviors of specimens in related tests were analyzed by a finite element software ABAQUS. And failure analysis was made. A reasonable expression on ductility optimization and improvement is drawed through nonliner regression. The results indicate that CFRP fracture is a principal reason of CFSST-CFRP stub column failure under axial compressive load. Meanwhile, its ductility can be improved by increasing the value of ξf/ξs,. Concrete-filled square steel tubular （CFST） stub column crack more seriously than CFSST-CFRP, and CFSST-CFRP stub column is not functioning adequately, without available CFRP bonded.