Revealing complex aspects of compressive failure of polymer composites - Part I: Fiber kinking at microscale

The fact that complex simulation can be carried out at present days allows to go further to answer new questions in the compressive failure of polymer composites. A thorough understanding of fiber kinking is essential for the prediction of stiffness and strength of fiber reinforced composites. The goal of this paper is to give a deep understanding of some topics which are still unclear in the micro modeling of fiber kinking. Such are the kinking mechanism and the difference in the kinking mechanics between global and local imperfections, the determination of kink band angle and consideration of statistical distributions of fiber waviness. 3D micro models are presented in Part-I in order to simulate the compressive failure in continuous fiber reinforced composites under pure compression considering the effect of fiber kinking. It is shown that the kinking mechanism is changed by changing the type of fiber waviness, the angle of the kink band is depend on the tensile strength of the fibers and the kink bands in a model with statistical distributions of fiber waviness are located at the edges of the specimen.