Micromechanics of Fatigue Damage in Unidirectional Polymer Composites

, 53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference 20th AIAA/ASME/AHS Adaptive Structures Conference 14th AIAA

Recommended citation: Garnich, Mark, Ray Fertig, Evan Anderson, Deng, Shiguang. 53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference 20th AIAA/ASME/AHS Adaptive Structures Conference 14th AIAA, Honolulu, HI, 2012.

Abstract: A work in progress is described that so far includes a finite element (FE) micromechanics modeling capability that generates random distributions of fibers in a periodic unit cell to predict fatigue damage in the matrix. The FE micromechanics model has automated features that facilitate parametric studies. This includes the ability to simulate any three-dimensional macroscopically uniform state of stress and to generate new fiber distributions within random-periodic unit cells that can have variable numbers of fibers. A damage evolution variable driven by the kinetic theory of fracture was implemented numerically in the FE computations. The spatial evolution of damage in the micromechanics model causes the deformation at some point to become unstable and define macroscopic failure of the composite. The effects of element size, time increment size, failed element residual properties, and fiber distribution were explored.