三维编织复合材料压缩性质应变率效应和破坏机理的频域研究

项目名称： 三维编织复合材料压缩性质应变率效应和破坏机理的频域研究

项目编号： No.10802022

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 电工技术

项目作者： 孙宝忠

作者单位： 东华大学

项目金额： 22万元

中文摘要： 三维编织复合材料在很多场合下经历冲击载荷，但因结构复杂，其冲击下的力学本构难以表征。本项目基于数字信号系统的频率变换理论，把系统在频域的所有重要概念引入到不同编织角、纤维体积含量、纤维束线密度和堆砌密度的四步法三维编织复合材料高应变率加载实验，分析由分离式Hopkinson压杆加载于三维编织复合材料试件时的应力、应变时域信号，得到三维编织复合材料系统的幅值谱、相位谱和传递函数，揭示复合材料在冲击加载下的动态响应；由系统的极点和零点分布讨论加载条件、细观结构对三维编织复合材料结构稳定性的影响、力学性质的应变率效应；研究冲击破坏机理的频域特征，发现隐藏于时域分析中的破坏新机制，并把研究内容扩张到其它纺织结构复合材料。研究结果积累了三维编织复合材料冲击加载力学性质基础数据，探索了三维编织复合材料在频域下的冲击破坏机制和各种频率响应特征，加深了对三维编织复合材料冲击损伤和破坏机理的认识。基于该项目研究结果，由科学出版社出版专著1本，发表论文被SCI收录20篇，培养11名研究生。

中文关键词： 三维编织复合材料；应变率；频率响应；破坏机理；结构稳定性

英文摘要： 3-D braided composites have an application invovling imacpt, and it is necessary to characterize the mechanical properties and dynamic reponse under high strain rates. With the supports of the granted funding, we investigated the dynamic responses of 3-D braided composite under impact loading and to find the response features in frequency domain. The compressive behaviors of 3-D braided composites with various braided angle, fiber volume fraction, fiber tow linear density and packing density have been tested on a split Hopkinson pressure bar (SHPB) apparatus. The stress, strain signals sampled from the SHPB apparatus have been transformed into frequency domain to obtain amplitude spectrum, phase spectrum and transform function. The concepts of digital signal theory have been incorporated into the analyses of the relationships between input signals and output signals of the 3-D braided composite under compression testing. And then the dynamic responses of the braided composite under impact loading have been investigated in the frequency domain. The influences of loading conditions and microstructures on the structure stability and strain rate effects have been discussed from the pole point and zero point distributions when the 3-D braided composite be considered as a discrete system. We also studied the impact mechanisms in the frequency domain to find the failure mechanisms that hidden in the time domain. The results accumulated the database contents of the 3-D braided composite under impact loading and find the damage mechanisms, frequency features in the frequency domain. From the project research, we have published a monograph by Science Press (Beijing) and 22 papers in international refereed journals which indexed in ISI Science Citation Index Expanded (SCI-EXPANDED). Eleven students obtained Master's Degree.

英文关键词： 3-D braided composite; strain rate; frequency response; failure mechanism;structure stability