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基于经典层板理论和细观力学桥联模型,提出了缝纫泡沫夹芯复合材料失效强度的理论预测方法,并进行了失效强度的相关试验验证。其中,将缝纫复合材料面板看作单层组成的准层状结构,采用经典层板理论进行逐层失效分析,并同时考虑了局部皱曲的面板失效模式;而对缝纫泡沫夹芯,引入桥联模型计算其各组分材料中的应力,并通过对各组分材料选取适当失效准则来建立失效判据;对于缝纫泡沫夹芯复合材料采取逐级加载方式,当面板或者夹芯失效时,则认为其发生整体失效,由此可以确定其在不同载荷形式下的失效强度。此外,通过试验得到了缝纫泡沫夹芯复合材料板试件在平压、侧压、横向剪切及三点弯曲载荷形式下的失效模式及其失效强度,并利用本文方法对缝纫泡沫夹芯复合材料的失效强度进行了理论预测,所得结果与试验吻合,证明了本文方法的有效性。
Based on the classical laminar theory and the meso-mechanics bridge model, a theoretical prediction method for the failure strength of the stitched foam sandwich composite is proposed, and the related test of failure strength is carried out. Among them, the sewing composite panel is considered as a quasi-layered structure composed of single layers, and the layer failure analysis by the classical laminar theory is taken into account. At the same time, the panel failure mode with partial buckling is considered; while for the sewing foam sandwich, The model is used to calculate the stress in each component material, and the failure criterion is established by selecting proper failure criteria for each component material. For the foam-sandwich composite material, the loading mode is step by step. When the panel or the core fails, It is considered as a whole failure, which can be determined under different load forms of failure strength. In addition, the failure mode and failure strength of the seamed foam sandwich composite plate specimens under flat pressure, lateral pressure, transverse shear and three-point bending load were obtained through experiments. The foam core- The failure strength of the material is theoretically predicted. The obtained results are in good agreement with the experimental results, which proves the effectiveness of the proposed method.