标题： 一种适用于实际圆柱壳的通用局部失效机制 显示英文标题

标题： A Universal Localized Failure Mechanism for Real Cylindrical Shells

摘要： 从细胞发育到太空火箭，薄壳的机械稳定性在许多工业和自然过程中至关重要。 然而，由于实际结构中不可避免地存在缺陷，预测壳体的失效特性仍然是一个开放性挑战。 现有的预测方法基于理想化壳体的经典稳定性分析，这些分析将壳体屈曲与自发出现的非定域屈曲模式相关联。 在这里，我们通过实验和数值观察表明，现实中的几何缺陷反而导致了一个普遍的局域屈曲模式。 尽管壳体的潜在缺陷结构各不相同，但该模式的轮廓在各种壳体中都具有鲁棒性。 进一步与经典预测相比较，在实际壳体中，即使在失效前稳定载荷下，其平衡表面变形也会以这种普遍的局域模式增长。 我们的研究结果表明，低于屈曲载荷的复杂非线性动力学由一个描述从鞍点分叉不稳定性屈曲结构的一维关系所描述。 这一突破为屈曲机制提供了简化但普遍的理解，从而改进了非破坏性的预测方法。 为了展示这些应用，我们实验实施了一种侧向探测技术，能够将几种未修改壳体的屈曲载荷预测到正确值的1%以内。 显示英文摘要

摘要： From cell development to space rockets, the mechanical stability of thin shells is crucial across many industrial and natural processes. However, predicting shells' failure properties remains an open challenge, owing to their sensitivity to imperfections inevitably present in real structures. Existing predictive methods are informed by classical stability analyses of idealized shells, which associate shell buckling with a spontaneously emerging delocalized buckling mode. Here, we show through experimental and numerical observations how realistic geometric imperfections instead result in a universal localized buckling mode. The profile of this mode is robust across shells despite their differing underlying defect structures. Further contrasting with classical predictions, a real shell's equilibrium surface deformations grow in the shape of this universal localized mode even at stable loads well before failure. Our findings show that these complex nonlinear dynamics for loads below buckling are described by a 1-D relationship for structures buckling from a saddle-node bifurcation instability. This breakthrough provides a simplified yet general understanding of buckling mechanisms, leading to improved non-destructive predictive methods. To showcase these applications, we experimentally implement a lateral-probing technique that predicts the buckling loads of several unmodified shells to within 1% of the correct value.