通过变分原理推导了弹性支撑圆弧拱考虑几何缺陷时的平衡方程,得到了外荷载与径向位移和轴力的关系,以及圆弧拱发生跳跃和分岔屈曲的平衡条件.用解析法和有限元法分析了几何缺陷和弹性支撑刚度对面内稳定性的影响.研究结果表明,两种方法在展开角较小时吻合良好;几何缺陷对屈曲路径有一定的影响,而弹性支撑刚度对跳跃屈曲的路径和临界值均有显著影响.
The equilibrium equations of elastic support circular arches considering the geometrical imperfections are deduced from the variation principle in this paper. And the relations between external load and radial displacement, axial forces are determined; also the equilib rium conditions of snap-through buckling and bifurcation buckling in circular arches are as certained respectively. Furthermore, the influences of geometrical imperfections and elastic supports on in-plane stability are analysed with the analytical method in this article and the finite element method. The results display that the two methods coincide with each other very well for smaller opening angle in circular arches. The geometrical imperfections have certain effects on the buckling path, while the elastic support rigidity plays a significant role in both the path and critical load of snap-through buckling.