四步法三维编织复合材料弯曲疲劳失效多尺度损伤模型

项目名称： 四步法三维编织复合材料弯曲疲劳失效多尺度损伤模型

项目编号： No.11502163

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 吴利伟

作者单位： 天津工业大学

项目金额： 20万元

中文摘要： 四步法三维编织复合材料不仅整体结构稳定、抗层间剪切性能优良，又具有极好的结构可设计性，在工程领域有极大的应用潜力。但任何结构件在使用过程中均会受到疲劳损伤的影响，为避免疲劳破坏所产生的安全隐患，延长使用寿命，对四步法三维编织复合材料疲劳性能及其损伤演化过程的研究至关重要。本项目将建立一种从纤维（细观）—纱线（中观）—试样（宏观）的多尺度弯曲疲劳损伤模型；开展四步法三维编织复合材料在弯曲加载条件下的准静态/疲劳性能测试；在实验测试的基础上，通过跨层次多尺度模型对四步法三维编织复合材料弯曲疲劳循环加载下的力学性能、结构效应以及损伤机理进行有限元分析，用于弥补单一尺度下有限元模型分析的不足，进一步揭示不同尺度下（尤其是纤维层面）的结构效应以及损伤机理，为四步法三维编织复合材料弯曲疲劳性能的优化提供理论依据。

中文关键词： 四步法三维编织复合材料；弯曲疲劳性能；多尺度；损伤模型；结构效应

英文摘要： The excellent structural stability and delamination resistance of four-step three-dimensional braided composites make them the promising material in engineering applications. However, they are inevitably subjected to fatigue damage during usage, leading to shorter service life and potential safety risk. Therefore, it is of great importance to investigate the fatigue property and failure evolution of four-step three-dimensional braided composite. In this study, firstly, the quasi-static and fatigue testing of four-step three-dimensional braided composites are conducted under bend loading by experiments. On the basis of experiments, a multi-scale fatigue model including fiber (Micro-scale) – yarn (Meso-scale) – fabric (Macro-scale) is established to deeply investigate the fatigue evolution and failure mechanism. Different from the analysis in individual scale, by analyzing the fatigue failure from micro-scale to macro-scale, the structural effect under different scales can be further revealed, especially for the fiber structure. This study will provide theoretical foundation for the fatigue performance optimization of four-step three-dimensional braided composite.

英文关键词： Four-step three-dimensional braided composite;Bending fatigue;Multi-scale;Fatigue model;Structural effect