轴压下大型薄壁圆柱壳的稳定性研究

承受轴向和周边径向压力的大型薄壁钢柱壳结构的稳定性分析是一个十分复杂的问题.根据理想壳体结构的屈曲平衡方程得出的临界应力,结合德国和我国的设计规范,通过有限单元法研究了初始缺陷、环向加劲肋间距、大开孔对薄壁圆柱壳稳定性的影响.结果表明:初始缺陷可使薄壁柱壳的极限屈曲应力降低至理想壳体临界应力的1/4以下;环向加劲肋间距的减小能够使得壳体极限屈曲应力显著增加,进而大大地提高了壳体的轴向承载力;大开孔的存在严重削弱了壳体的整体稳定性.上述结论对于薄壁柱壳的稳定性分析具有一定的理论意义和实用价值.

Study of stability of large-scale thin-walled cylindrical shells under axial compression

The analysis of stability of large-scale thin-walled cylindrical shells in electric power engineering is a complex problem.Generally,the shells are subjected to axial compression and internal pressure.In this paper,DIN18800 is combined with GB150.The effects caused by initial imperfection,the length of adjacent stiffeners as well as large opening on stability of large-scale thin-walled cylindrical shells are studied through finite element analysis.The research shows that initial imperfection can reduce limit buckling stresses to be below one fourth of its ideal buckling stresses.In addition,the limit buckling stresses of thin-walled shells is markedly increased by ring stiffeners.Large opening can sharply weaken global stability of cylindrical shells.The results are helpful to the research on stability of thin-walled shells in both theoretical and practical significance.