针对航空用纤维复合材料,基于纤维与基体的协调变形规律和材料应变能密度的计算,导出了纤维复合材料的刚度表达式,研究了刚度矩阵的基本力学特性,给出了复合材料刚度矩阵元素与基体材料的刚度、纤维束的刚度及铺设方向的关系,提供了平面铺层和三维取向纤维复合材料的基本刚度设计公式和设计方法。最后给出工程应用设计方法的几个具体例子,并与其他理论和实验结果进行了对比。研究结果表明,在考虑材料制备工艺缺陷造成的刚度折减后,本文提出的设计公式及方法可应用于纤维复合材料的优化设计。
In this article, stiffness tensor of materials is derived for fibrous composites of aerial materials, based on the compatibility relation of deformation of fibers in matrices and the strain energy density of the fibrous composites. Principal mechanical properties of the stiffness matrix are investigated to derive the relations between material stiffness and matrix stiffness, and between stiffness of fibers and their orientations. More- over, fundamental formulas and methods for stiffness design of laminated and spatially distributed fibrous composites are provided. Finally, examples are given to illustrate how to use the design formulas and compare them with other theories and experimental data. The research results indicate that after considering the stiffness discount due to imperfect of manufacture technology, the proposed formulas and methods can be applied to the optimization of design with fibrous composites.