Optimization of fiber arrangement with CAIO (computer aided internal optimization) and application to tensile samples

摘要

The understanding of the internal optimization of trees leads to the development of a method for the optimization of the internal arrangement of fibers in composite materials. The CAIO method is based on FEM and copies biological fiber orientation in order to minimize shear stresses within orthotropic or multilayer composite material structures. Tests on specimens of fiber-reinforced material proved that structures with optimized material directions bear higher loads than unidirectional ones. It is evident that the mechanism of failure changes from shear failure of the unidirectional specimen to an excess of the ultimate tensile strength of the optimized specimen. With the latest version of CAIO, it is possible to calculate fiber orientations in three-dimensional structures. The optimization procedure reduces the shear stresses as well as the principle stresses. CAIO also allows the consideration of local changes of stiffness for curvilinear fiber-reinforced materials.