薄壁短柱轴压承载力的非线性有限元分析与计算

利用ANSYS8.1有限元程序对冷弯薄壁帽形截面及卷边槽钢短柱的承载力进行了非线性有限元分析。分析中考虑了材料非线性和初始几何缺陷的影响,提出了合理的有限元分析模型与网格划分密度,分析结果与试验资料吻合较好。此外,分别利用传统的有效宽度法和新兴的直接强度法计算了短柱段的极限承载力,并对翼缘宽厚比超过规范限值的情况提出了计算建议。两种方法除在部分截面的分析中得到较为保守的结果外,其余均与试验值比较接近。直接强度法计算上更加简便,且精度高于有效宽度法,是计算薄壁构件承载能力非常有效的新方法。

Nonlinear Finite Element Analysis and Calculation for Axial Loaded CarryingCapacity of Thin-walled Stub Columns

Axial loaded carrying capacities of cold-formed thin-walled hat-section and lipped channel stub columns are studied by nonlinear finite element analysis using ANSYS program.The influence of material plasticity and geometric imperfection is considered in the analysis.The reasonable finite element model and meshing are set up.Results from the analysis agree well with experimental data.Furthermore,the ultimate carrying capacities are computed using traditional effective width method and direct strength method respectively.The design proposal for sections,which flange width-to-thickness ratio exceeds sixty,is provided.The results of two methods are all close to the experimental data except conservative results for a few sections.Direct strength method is simpler and more accurate than effective width method.