冷成型双相型不锈钢轴心受压构件承载力分析

Numerical Study of Bearing Capacity of Cold-formed Duplex Stainless Steel Columns

建立了准确的有限元模型,对双相型不锈钢轴心受压短柱和长柱进行了模拟分析,并依据已有试验结果对模型的准确性进行了验证,方管、圆管短柱的试验值与其对应有限元计算结果误差均在5%以内;对于方管与圆管长柱,试验值与其对应有限元计算结果的误差分别为2.3%和3.8%.基于验证的有限元模型开展了参数化分析,发现双相型不锈钢材料力学性能参数变化对轴心受压构件承载力的影响不大;构件截面几何参数对于圆管仅影响长细比较小构件的承载力,承载力变化幅值为16%,对于方管则影响较为显著。基于有限元分析结果,考虑相关参数对圆管和方管柱子曲线影响不同以及材料屈服后强化的特性,对现行规范中的柱子曲线进行改进。允许构件的承载力高于截面屈服轴力,分别提出了方管和圆管承载力建议计算公式,为《不锈钢结构技术规程(CECS410:2015)》的修订提供理论依据。

The duplex stainless stub and long columns were simulated and analyzed by establishing accurate finite element models,and the accuracy of the model was verified by experimental results.The errors between experimental values and corresponding FEM calculation results of square and round stub tubes are all less than 5%.For the long square and round columns,the errors are 2.3%and 3.8%,respectively.Upon the validation of accuracy for the FE models,systematic parametric studies were carried out.It was found that the change in mechanical properties of duplex has little influence on the bearing capacity of axial compression members.The geometric parameters of cross-section only affect the bearing capacity of the round tubes with small slenderness ratio,and the change amplitude of bearing capacity is 16%.For square tubes,the effect is more significant.Therefore,the column curves of square and round tubes were improved on the basis of the influence of relevant parameters and the strain hardening characteristics of material.The calculation formulas for the bearing capacity of square tubes and round tubes were proposed,which provides a theoretical basis for the revision of the"Technical Specifications for Stainless Steel Structures(CECS410:2015)".