火电厂大型薄壁圆柱钢壳的轴压稳定性能研究

Study of stability of large-scale thin-walled cylindrical steel shell for thermal power plant under axial compression

考虑施工过程中焊缝引起的初始缺陷,对圆柱壳进行弹性屈曲分析,研究了不同初始缺陷幅值下圆柱壳的屈曲应力,结果表明施工过程中焊缝收缩引起的圆柱壳环向初始缺陷对圆柱壳的弹性屈曲影响显著,可使屈曲应力降至理想圆柱壳的0.22～0.43倍.根据吸收塔施工验收规程,考虑施工制作过程中产生的几何初始缺陷,对圆柱壳进行了弹塑性屈曲分析,得到了圆柱壳在轴压状态下的受力性能,以及相关的荷载位移曲线,并对比了各规范方法计算结果,给出了建议的稳定承载力设计值.

Considering the initial weld defects induced by the construction process,elastic buckling analysis of cylindrical shell is carried out under different initial imperfection amplitudes.The results show that elastic buckling stress of cylindrical shell is affected significantly by circumferential weld shrinkage during construction,and reduced to 0.22-0.43times that of ideal cylindrical shell.According to the code for construction and acceptance of flue gas desulphurization absorber of thermal power plant,considering the initial geometric defects produced during the process of construction of cylindrical shell,the performance of cylindrical shells under axial compression condition is studied by elastoplastic buckling analysis;and the load displacement curves are obtained.Meanwhile,the results calculated by different codes are compared.Finally,the suggested design values of stability stresses are given.