CFRP積層板の斜め方向引張り特性とマイクロメカニクスの手法を用いた非線形積層理論

抄録

This paper deals with the deformation and damage of CFRP cross-ply laminates under off-axis tension and develops a non-linear lamination theory. Off-axis tensile tests were carried out on five kinds of CFRP cross-ply laminates which were different in stacking lay-up. On the laminates under off-axis tension, the stress-strain response shows the non-linear deformation, while the ply-cracking damage is not remarkable except for the specimen with large fracture strain. Therefore, It is concluded that the non-linear deformation of the laminates under off-axis tension is mainly attributed to the non-linear deformation of the matrix resin. In order to describe the deformation of the laminates, a non-linear lamination theory is developed. An incremental constitutive relation of the unidirectional composite containing elastic long fibers in the elastic-plastic matrix is derived based on Eshelby's equivalent inclusion method and Mori-Tanaka mean field concept. Then, this constitutive relation is introduced Into the classical lamination theory. Numerical results by the present theory for off-axis tension of the CFRP unidirectional and cross-ply laminates well described the experimental stress-strain relations.