Abstract

The influence of local thinning thickness defects on the buckling of cylindrical shells is investigated. A static buckling model of cylindrical shells with defects is established based on the Hamiltonian system. The complete symplectic eigensolutions of the cylindrical shell are superimposed to derive the buckling modes of the cylindrical shell with defects. A total of seven different cylindrical shells with axisymmetric and non-axisymmetric defects are considered. Local buckling modes can be captured by this new analytical model with symplectic methodology. By constraining the defect volume, the influence of different defect shapes on buckling of the cylindrical shell is investigated. Comparing with step defects and parabolic defects, the analysis concludes that defects of exponential function are more harmful to buckling of cylindrical shells.

• Highlights

• This article establishes a cylindrical shell model with arbitrary thickness changes under the Hamiltonian system and evaluates the buckling characteristics of cylindrical shells with thickness defects.

• A new symplectic approach is developed where the symplectic eigensolutions of the complete cylindrical shell are superimposed to obtain the corresponding buckling modes.

• Local buckling modes can be captured by this new analytical model. The occurrence of local buckling often drives a significant decrease in critical buckling load.

• The effects of defect parameters including location, depth, and shape on structure buckling are determined and analyzed.

摘要

研究了局部减薄厚度缺陷对圆柱壳屈曲的影响。基于哈密顿系统建立了含缺陷圆柱壳的静态屈曲模型。叠加圆柱壳的完全辛本征解，推导出有缺陷圆柱壳的屈曲模态。总共考虑了七个具有轴对称和非轴对称缺陷的不同圆柱壳。这种采用辛方法的新分析模型可以捕获局部屈曲模式。通过约束缺陷体积，研究了不同缺陷形状对圆柱壳屈曲的影响。与台阶缺陷和抛物线缺陷相比，分析得出指数函数缺陷对圆柱壳屈曲的危害更大。

• 强调

• 本文建立了哈密顿系统下任意厚度变化的圆柱壳模型，并评估了具有厚度缺陷的圆柱壳的屈曲特性。

• 开发了一种新的辛方法，将完整圆柱壳的辛特征解叠加以获得相应的屈曲模式。

• 这种新的分析模型可以捕获局部屈曲模式。局部屈曲的发生通常会导致临界屈曲载荷显着降低。

• 确定并分析了包括位置、深度和形状在内的缺陷参数对结构屈曲的影响。