夹芯结构面内压缩强度损伤容限研究

Damage Tolerance Analysis on In-plane Compression Strength of Sandwich Structure

  • 摘要: 金属泡沫复合材料夹芯结构在实际使用过程中会受到各种外物的冲击,降低夹芯结构的刚度和强度,出现局部损伤现象,从而影响夹芯结构的安全性。针对夹芯结构受到低速冲击后产生不同的局部损伤类型,开展金属泡沫夹芯结构面内压缩强度损伤容限研究。通过有限元仿真方法建立夹芯结构的剩余压缩强度模型,仿真结果与试验结果对比验证模型的有效性,并采用该模型预测并分析不同损伤类型对夹芯结构剩余压缩强度的影响以及压缩强度对不同损伤的尺寸敏感度。结果表明:凹痕和面板分层是导致剩余压缩强度下降的重要因素;当模型含有分层损伤时,凹痕的存在会延缓结构出现压缩破坏;对于大多数损伤类型,剩余压缩强度会随其尺寸增大而降低。

     

    Abstract: The core structure of metal foam composite material will be impacted by various external objects during the actual use, which will reduce the stiffness and strength of the sandwich structure and cause local damage, thus affecting the safety of the sandwich structure. Aiming at the different local damage types of sandwich structures subjected to low velocity impact, the damage tolerance of in-plane compressive strength of metal foam sandwich structures is studied. The residual compressive strength model of sandwich structure is established by finite element simulation method. The validity of the model is verified by comparing the simulation results with the test results. The influence of different damage types on the residual compressive strength of sandwich structure and the size sensitivity of compressive strength to different damage are predicted and analyzed. The results show that dent and delamination are the important factors leading to the reduction of residual compressive strength, that when the model contains delamination damage, the existence of dent will delay the compression failure of the structure, and that for most damage types, the residual compressive strength will decrease with the increase of the sizes.

     

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