文献类型：期刊文献

英文题名：Mechanical failure and strengthening mechanism of nanoporous phenolic composites reinforced with needle-punched fiber preforms of different needle-punched densities

作者：Cai, Hongxiang[1];Jiang, Zhen[2];Li, Liang[1];Zhang, Xuanfeng[2];Zhu, Xiaofei[2];Tian, Hao[1];Wang, Peng[1];Cao, Yu[1,3];Zhang, Yayun[1,3];Niu, Bo[1,3];Long, Donghui[1,3]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Shanghai Acad Spaceflight Technol, Shanghai Space Prop Technol Res Inst, Shanghai, Peoples R China;[3]Suzhou Lab, Struct Mat Res Dept, Suzhou, Peoples R China

年份：2025

卷号：46

期号：S1

起止页码：S326

外文期刊名：POLYMER COMPOSITES

收录：;EI(收录号：20251218079333);WOS:【SCI-EXPANDED(收录号:WOS:001441304900001)】；

基金：This work is supported by the National Natural Science Foundation of China (Nos. 22078100, U2341291, 52472095) and Young Elite Scientists Sponsorship Program by CAST (2022QNRC001).

语种：英文

外文关键词：mechanical failure mechanism; nanoporous phenolic composites; needle-punched composites; X-ray computed tomography

摘要：Needle-punched fiber preforms are extensively employed as reinforcements for low-density thermal protection materials (TPMs) due to their high design flexibility and cost-effectiveness. However, the inherent complexity and randomness of the needle-punched technique present challenges in elucidating the impact of needle-punched parameters on the mechanical performance of these materials. Herein, needle-punched preforms, including needle-punched fiber felts (NF) and needle-punched woven fabric/felt (NWF), are deliberately designed with varying needle-punched densities (0, 10, 30, 50 punches/cm(2)) to reinforce the nanoporous phenolic composites (NPCs). The mechanical performance and failure mechanism of these composites are comprehensively investigated. Tensile testing results reveal that a small number of needle-punched fiber bundles along the Z-axis improve the in-plane tensile properties of both NF and NWF reinforced NPCs, owing to the rivet-like structure of needle-punched fibers that hinders crack propagation. However, as the needle-punched density increases, the tensile performance of NPCs gradually decreases due to increased damage induced by the needle-punched fibers. Conversely, the interlaminar shear performance and fracture toughness of NPCs are progressively improved with increasing needle-punched density, as the effectiveness of the rivet-like structure is enhanced. The present work will provide valuable insights for the design and optimization of needle-punched fiber preform reinforced composites.