钢管混凝土构件承载力分析的纤维模型法关键参数研究

RESEARCH ON KEY PARAMETERS OF FIBER MODEL METHOD FOR ANALYSIS OF BEARING CAPACITY OF CONCRETE-FILLED STEEL TUBE

以圆形截面为例,采用纤维模型法对钢管混凝土构件承载力进行分析。为确定纤维模型法关键参数及其合理取值,首先建立了圆钢管混凝土轴压和纯弯构件承载力分析的纤维模型法计算式;然后分析离散单元数量、收敛容差、应变增量、挠度增量和初始偏心距等参数对计算结果的影响规律,并以此确定影响纤维模型法计算结果的关键参数及其合理取值;最后,通过与钢管混凝土构件承载力试验数据进行比较,验证所确定的纤维模型法关键参数取值的合理性。结果表明:钢管混凝土构件受力状态不同,纤维模型法的关键参数取值也有所不同,所确定的关键参数取值能够保证纤维模型法计算结果稳定收敛,且具有较高的计算精度和广泛的适用性。

A fiber model method was presented for the bearing capacity analysis of concrete-filled steel tube(CFST)members with circular sections.The key parameters of the fiber model method and their reasonable values were determined.Firstly,the formula of the fiber model method was presented for the strength analysis of circular CFST members under axial compression and pure bending.Secondly,combined with experimental data,the influence of discrete element number,convergence tolerance,strain increment,deflection increment and initial eccentricity on the fiber model method were discussed.Then,the key parameters and their reasonable values were determined.Finally,the test results were utilized to verify the validity of the values taken by key parameters of the fiber model method determined in the paper.It was shown that the determined key parameters of the fiber model method had a slight difference with the loading conditions.The key parameters determined in the paper could guarantee the convergence of the fiber model method with high accuracy and wide applicability.