多层不等厚组合圆柱壳屈曲数值模拟分析

针对大型立式组合圆柱壳结构的几何特征,采用数值模拟方法分析了多层不等厚特征因素对圆柱壳屈曲临界载荷的影响.提出多层不等厚可看成是圆柱壳壳壁上的几何缺陷,在一定程度上会减弱经典圆柱壳的屈曲临界应力水平.建立数个多层不等厚组合圆柱壳的屈曲分析有限元（FEA）模型,初步分析了不同载荷工况下多层组合圆柱壳的屈曲行为,得到相应的屈曲失稳临界载荷,验证了环向应力对组合圆柱壳屈曲的影响规律.结果表明,多层不等厚特征因素可明显降低经典圆柱壳的屈曲临界载荷,其中层数和相邻圆柱壳壁厚差值对屈曲临界载荷的影响最大.

Numerical simulation on buckling of combined multilayered unequal-thickness cylindrical shell

The influence of the characteristic factor of unequal-thickness on critical buckling load was analyzed by numerical simulation method based on geometric features of large vertical combined cylindrical shell. The character of unequal-thickness was considered as geometrical defect, which decreases the critical stress of classical shell buckling to some extent. Finite element analysis (FEA) models of combined multilayered unequal-thickness cylindrical shell were built to analyze the buckling of combined cylindrical shell under different loadings. Critical loads of instability buckling under different loadings were obtained to verify the influence regularity of hoop stress on the buckling of combined cylindrical shell. Results show that the characteristic factor of unequal-thickness can largely decrease the critical load of classical shell buckling. And the number of layers and the thickness difference of adjacent shell courses have the biggest influence on critical buckling load．