三维编织复合材料整体结构强度研究

The macro- and micro-mechanical behaviors, failure mechanism and strength of three-dimensional (3D) braided composites are studied in the project. Based on micro-structure, a representative unit cell model, which coincides with the actual configuration of 3D braided composites, is presented. The model can improve the theoretical prediction precision of 3D braided composites. Based on the multivariable FEM and homogenization method, the macro- and micro-mechanical model of 3D braided composites is presented and the relation between the macro-mechanical properties and micro-stuctures is set up. According to the different failure modes, the corresponding stregth criterion models and stiffness reduction methods are presented in the project.A high effeciency finite element method to calculate the strength of 3D braided composite structures is studied based on the fixed finite element method. A new mechanical numerical simulation software for multiphase materials, which possesses intellectual property, is developed. The project belongs to a basic research work. The achievements provides an exploratory mechanical characterization and strength prediction method for 3D braided composite structures. In addition, some useful theories and methods are presented in the project, which falicite 3D braided composite structures being applied in aeronautics and astronautics, automobiles, vessels, and machine fields.

本项目拟对三维编织复合材料的宏微观力学行为、失效机理和强度预测开展深入系统的研究。针对三维编织复合材料结构，提出能够反映实际构造的单胞几何模型，提高理论预报精度。结合三维编织复合材料的细观构型，基于多尺度自洽模型及均匀化理论，建立宏微观力学模型，研究三维编织复合材料结构宏观力学性能与细观结构参数之间的关系。针对不同失效形式，建立相应的破坏模型与准则，提出刚度衰减方法。利用混合有限元思想，提出一种能够快速、高效预报编织复合材料复杂结构件强度的数值计算方法。在此基础上，形成具有自主知识产权的多相非均质材料计算力学软件。本研究属于前沿性的基础研究，其研究成果一方面为三维编织复合材料结构力学行为的表征和强度预报提供一种探索性的方法，同时也为编织复合材料及其结构在航空航天、汽车、舰船、机械等领域的设计和应用提供了理论基础和技术储备。

本项目对三维编织复合材料结构在不同载荷条件下的宏细观力学行为、失效机理、强度开展了深入系统的研究。针对三维编织复合材料结构，提出了能够反映实际构造的单胞几何模型，提高了理论预报精度。结合三维编织复合材料的细观构型，基于多尺度自洽模型及渐近展开均匀化理论，建立了宏细观力学模型，研究了三维编织复合材料结构工程弹性常数、热物理性能以及宏观力学性能与细观结构参数之间的关系。针对不同失效形式，建立了相应的破坏模型与准则，提出了刚度衰减方法。利用混合有限元思想，提出了一种能够快速、高效预报编织复合材料复杂结构件强度的数值计算方法。在此基础上，形成了具有自主知识产权的多相非均质材料计算力学软件。本研究属于前沿性的基础研究，其研究成果一方面为三维编织复合材料结构力学行为以及热力学行为的表征和强度预报提供了一种探索性的方法，同时也为编织复合材料及其结构在航空航天、汽车、舰船、机械等领域的设计和应用提供了理论基础和技术储备。