钢管混凝土纯压拱失稳临界荷载计算的等效柱法

在双重非线性有限元分析的基础上,进行了钢管混凝土纯压拱失稳临界荷载的简化计算方法——等效柱法的研究,提出了等效柱法中考虑矢跨比影响的稳定系数K₁ 以及考虑初始几何缺陷影响的折减系数K₂及其与现有规范相对应的计算公式。与有限元计算结果的对比表明,采用考虑矢跨比因素的稳定系数的等效柱法能较精确地估算钢管混凝土纯压拱的非线性失稳临界荷载,且计算精度受含钢率和钢材种类变化的影响较小。

Equivalent column method to calculate critical load for concrete-filled steel tubular arch under pure compression

Based on the finite element analysis considering dual-nonlinearity, the investigation of simple method - equivalent column method to calculate the critical loads of concrete-filled steel tubular arch under pure compression is carried out. The stability factor K₁ considering influence of rise-to-span factor and the discount factor K₂ considering effect of initial crookedness are presented for equivalent column method. Practical formula are given out by using critical load of short column in different CFST structure design codes. By comparison with the finite element results, the presented method can estimate nonlinear critical load of CFST arch under pure compression accurately, and the change of steel ratio and steel type has little effect to its precision.