摘要
碳泡沫是一种比强度高、导热导电率可控的新型功能结构材料,在复合材料成型模具制造等领域具有广阔的应用前景。本工作通过试验研究碳泡沫复合材料夹层结构在准静态横压状态下的损伤过程,提出适用于横观各向同性碳泡沫的失效判据,分别建立不考虑胶黏剂渗入区域和考虑渗入区域的夹层结构有限元模型,利用试验结果对模型的有效性进行验证,并进一步讨论相关参数的影响。结果表明,碳泡沫复合材料夹层结构在准静态横压后主要发生芯材的压缩破坏和剪切破坏,以及上面板的基体开裂和分层破坏。损伤过程为芯材塌陷、芯材45°或竖直开裂、芯材与面板分离,同时伴随上面板基体开裂和分层。与PMI泡沫和铝泡沫的损伤形貌相比,碳泡沫内部存在少量随机分布的裂纹。有限元模型满足分析精度要求,可以很好地模拟出夹层结构的准静态横压损伤过程。准静态横压能量和极限载荷随面板厚度和芯材厚度的增大而增大,与胶层厚度和压头直径没有明显的相关性;面板使用±45°铺层可有效提高夹层结构的准静态横压能量。
Carbon foam is a new functional and structural material with characteristics like high specific strength and adjustable conductivity and thermal conductivity,which has wide application prospect in carbon foam-based polymer matrix composites tooling manufacturing.In this work,the damage process of carbon foam sandwich structure with carbon fiber reinforced composites(CFRP)under quasi-static transverse indentation was studied experimentally,and the failure criterion applicable to transversely isotropic carbon foam was proposed.Finite element models of sandwich structure without considering the adhesive penetration area and considering the penetration area were established respectively.The effectiveness of the model was verified by the test results,and the influence of relevant parameters was further discussed.The results show that the sandwich structure mainly occurs the compression and shear failure of carbon foam,and the matrix crack and delamination of top face sheet.The damage process consists of carbon foam collapsing,carbon foam 45°or vertical cracking and carbon foam-face sheets separating accompanied by matrix cracking and the delamination of top face sheet.Compared with the damage morphologies of PMI foam and aluminium foam,there are several random cracks in the carbon foam.The finite element models meet the analysis accuracy requirements,and the numerical prediction of damage process shows good agreement with experimental results.The further analysis shows the greater the thickness of carbon foam and face sheets are,the more quasi-static indentation energy and the greater peak force,and the diameter of indenter and the thickness of adhesive have no obvious relationship with quasi-static indentation energy and peak force.Face sheets with±45°layups can improve quasi-static indentation energy of the sandwich structure effectively.
作者
罗智涛
庄淇凯
李小琪
李凯
程小全
LUO Zhitao;ZHUANG Qikai;LI Xiaoqi;LI Kai;CHENG Xiaoquan(School of Aeronautic Science and Engineering,Beihang University,Beijing 100191,China;Department of Chemical Protection,Research Institute of Chemical Defense,Beijing 100191,China;Beijing Institute of Spacecraft System Engineering,Beijing 100094,China;Ningbo Institute of Technology,Beihang University,Ningbo 315800,Zhejiang,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2024年第16期81-89,共9页
Materials Reports
关键词
碳泡沫
失效判据
复合材料
夹层结构
准静态横压
carbon foam
failure criterion
composite
sandwich structure
quasi-static indentation
