矩形钢管混凝土抗弯性能数值分析与简化计算

为了深入认识压弯构件的工作机理,进一步确定抗弯刚度等力学指标,根据简化钢材本构关系和考虑约束效应的核心混凝土本构关系,采用有限条分法计算纯弯构件的弯矩-曲率曲线,并与试验结果进行对比,二者吻合良好;对试验和数值分析曲线线性拟合得到构件弹性阶段的抗弯刚度,提出其简化计算式;分析影响纯弯构件承载力的影响因素,提出考虑钢管塑性发展的简化计算公式,并与试验结果进行对比,结果表明,该计算式可以有效地计算矩形钢管混凝土的抗弯承载力.

Numerical Analysis of CFRT Under Bending Load and Its Simplified Calculating Method

In order to study the mechanism of concrete-filled rectangular steel tubes(CFRT) subjected to compression-bending load and determine mechanical indexes such as flexural rigidity,the finite strip method,which was based on the simplified constitutive relationship of steel and the constitutive relationship of in-core concrete considering confining effect,was adopted to acquire moment-curvature curves of CFRT subjected to bending load.Then theoretical results were compared with test data,indicating that they fit well with each other.By linear fit of experimental and numerical curves,the elastic flexural rigidities of members were acquired,and the simplified calculating equation of flexural rigidity was put forward.Based on the analysis of factors affecting the bearing capacity of CFRT subjected to bending load, the simplified calculating equation considering the plastic development of steel tube was also put forward,and the results were compared with test data,showing that the equation could effectively estimate the bearing capacity of CFRT subjected to bending load.