マイクロメカニクスに基づく複合材料積層板のトランスバースクラック進展解析

抄録

Polymer matrix composites (PMCs) that have high specific strength and specific rigidity have been used in aerospace fields. Fiber-reinforced composite laminates exhibit specific fracture processes such as transverse cracks (cracks in a direction parallel to the fiber), delamination, and breakage of the fiber. In these fracture processes, transverse cracking occurs in the earliest stage. Therefore, it is important to clarify the mechanical behavior of laminate including transverse cracks. To evaluate the relationship between the mechanical behavior of composite laminates and transverse cracking, we formulated the continuum damage mechanics model for predicting the stiffness reduction of composite laminates including transverse cracks and the transverse cracking progression model in laminate including 90° plies. For development of the present models, stress field model, which takes into account thermal residual strain for plies including transverse cracks, was formulated based on micromechanics. Then, the damage variable in the direction normal to the fiber of a ply including transverse cracks and the energy release rate associated with transverse cracking were calculated using stress field model for plies. Finally, we compared the results obtained from present models to those of the finite element analysis (FEA) and experiment results reported in previous studies. Consequently, present models could predict the FEA results and experiment results quantitatively.