Experimental and numerical investigation on enhancing the structural integrity of composite sandwich structure
Experimental and numerical investigation on enhancing the structural integrity of composite sandwich structure
复制标题
DOI：
10.1177/1369433219836177
复制
发表时间：
2019-07-01
影响因子：
2.6
通讯作者：
Mostafa, A.
中科院分区：
文献类型：
--
作者：
Mostafa, A.
复合材料夹层结构具有独特的特点，其面板材料提供了很高的面内刚度/强度，而芯材使面板保持一个部分，以提高抗弯刚度/强度。然而，由于夹层结构面板与芯材之间的粘结较弱，夹层结构容易发生剪切破坏。本文解决了这一问题，并提出了一种有效的半圆剪切键概念，该概念可插入夹层结构元件之间的界面表面，以改善面板-核心的相互作用，同时降低强度-重量比。本文研究了由玻璃纤维增强聚合物表皮和聚氨酯泡沫芯材组成的复合夹层板。对面板进行机械拉伸、压缩和剪切试验，对芯材进行压缩试验，以确定构件材料的弹塑性响应。对传统复合材料夹芯板和加入剪切键概念的夹芯板进行了四点弯曲试验。对于加入剪切键的样品，随着裂缝路径的迂回，抗弯刚度和强度有了相当大的改善。建立了非线性有限元分析来验证实验结果。实验结果和有限元结果之间的比较表明，两者之间的结果很好地吻合，这证明了有限元模型中使用的参数及其捕获所研究模型的力学行为和损伤模式的能力。
Composite sandwich structure possesses unique characteristics in which the facings' material provides a high in-plane stiffness/strength, while the core material keeps the facings a part to enhance the flexural stiffness/strength. However, sandwich structure is susceptible to shear failure due to the weak bond between the facings and the core materials. This article addresses this issue and provides an efficient semi-circular shear keys concept to be inserted in the interfacial surface between the sandwich structural elements to improve the facings-core interaction with marginal sacrifice in the strength-to-weight ratio. Composite sandwich panels composed of glass fibre-reinforced polymer skins and polyurethane foam core material have been investigated in this study. Mechanical tension, compression and shear tests were performed on the facings, while compression tests were conducted on the core materials to define the elasto-plastic response of the constituent's materials. Four-point bending tests were performed on the conventional composite sandwich panel and panels incorporated with shear keys concept. Considerable improvement in the flexural stiffness and strength along with detouring the crack path was noticed for the samples incorporated with shear keys. A non-linear finite element analysis was established to verify the experimental results. Comparisons between the experimental and finite element results were presented and showed good agreement between both results which justified the parameters used in the finite element models and their capabilities to capture the mechanical behaviour and the damage mode of the investigated models.