多级加筋板结构承载性能与缺陷敏感度研究

摘要

Based on the widely used traditional stiffened panel in the field of aerospace,an innovative hierarchical stiffened pan-el was proposed.By means of dynamic explicit analysis,the ultimate load-carrying capacities of the traditional and hierarchical stiff-ened panels with equivalent mass subjected to axial compression were investigated via the numerical method. Results show that the collapse load of the hierarchical stiffened panel increases approximately by 10%.Meanwhile,the effect of the height ratio of large and small stiffeners on the perfect hierarchical stiffened panel was discussed.The imperfection sensitivities of these two models with var-ying amplitudes and distributions of the single dimple imperfection were studied in detail. It is found that the hierarchical stiffened panel shows low imperfection sensitivity compared to the traditional stiffened panel.This may be attributed to the multiple stiffener si-zes which lead to the periodic distribution of the stiffness of structures,and thus the development of deformations caused by geomet-rical imperfections is restricted to local regions. Finally,the effect of the height ratio of large and small stiffeners on the imperfect hi-erarchical stiffened panel was investigated.%针对航空航天领域传统的加筋板结构，提出了一种新型多级加筋板结构形式。首先基于显式动力学方法，数值分析对比了相同质量的单级与多级加筋板在轴压工况下的极限承载能力，结果表明，多级加筋板的极限承载载荷值相较于单级加筋板提高约10％，进而分析了筋高比对完美多级加筋板极限承载能力的影响。以单点凹陷型缺陷为例，对加筋板开展了缺陷敏感度分析，考察了缺陷的幅值与位置对结构承载能力的影响，发现相较于单级加筋板，多级加筋板由于加筋形貌更为丰富，导致其局部抗弯刚度呈现周期性变化，可有效将缺陷诱发的局部失稳抑制在局部区域内，表现出更优异的抗缺陷能力，在此基础上最后分析了筋高比对含缺陷的多级加筋板极限承载能力的影响。