The nonlinear stability analysis of a structure with initial geometric imperfections is very complex, difficult, and unsolved yet in designing. At present, there are no unified design guidelines for imperfection sensitive metal shells (spherical, cylindrical, conical, and so forth), and the study about composite shell structures is often for a specific ply parameter and therefore less adaptable. In this paper, the imperfection sensitivity analysis of orthotropic conical shells with and without cutouts under compression is investigated numerically. The eigenmode-shape imperfections and dimple-shape imperfections are introduced to conical shells with different cutout sizes. In order to find the worst imperfections that can reduce the buckling load as far as possible, an optimization framework based on the multiple perturbation load approach is developed by the present authors to search the possible positions of dimple-shape imperfections; the effectiveness of the algorithm has been proved by comparing with other conventional approaches.Mid-surface imperfections, a type of realistic imperfection, transferred from a cylinder are considered for a conical shell with a cutout at last. This work can provide a reference value for conical shell design for practical engineering applications.

中文翻译：

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几何缺陷对有或没有切口的轴向载荷复合圆锥壳的影响

具有初始几何缺陷的结构的非线性稳定性分析非常复杂，困难并且尚未在设计中解决。目前，对于不完善的金属壳（球形，圆柱形，圆锥形等）尚无统一的设计指南，有关复合壳结构的研究通常针对特定的层板参数，因此适应性较差。本文通过数值研究了带有或不带有切口的正交各向异性圆锥壳的缺陷敏感性分析。本征模态缺陷和酒窝形缺陷被引入到具有不同切口尺寸的圆锥形壳体中。为了找到可以最大程度降低屈曲载荷的最严重缺陷，作者开发了一种基于多重扰动载荷方法的优化框架，以寻找酒窝形状缺陷的可能位置。最后，对带有切口的圆锥形壳体考虑了从圆柱体转移来的中表面缺陷，这是一种真实的缺陷，是从圆柱体上转移出来的。这项工作可以为实际工程应用中的锥形壳体设计提供参考价值。从圆柱体上移出的材料最后被考虑为带有切口的圆锥形外壳。这项工作可以为实际工程应用中的锥形壳体设计提供参考价值。从圆柱体上移出的材料最后被考虑为带有切口的圆锥形外壳。这项工作可以为实际工程应用中的锥形壳体设计提供参考价值。