Multiscale Analysis of CFRP Laminates Including the Effect of Fiber Waviness

摘要

This paper proposes a numerical analytical method for carbon fiber reinforcedplastic (CFRP) laminates, where fiber orientation is disturbed due to manufacturingdefect. In the CFRP laminates, it is not unusual to find internal microscopic defectsincluding fiber waviness, voids, or resin pockets. Among them, fiber waviness has astrong effect to the compressive strength of the CFRP. Therefore, it is very importantto simulate the effect of the fiber waviness on the stress distribution in the CFRPlaminates. In this paper, the authors propose a numerical method which can includevarious modes of fiber waviness by simple method. In this model, fiber waviness isintroduced as a combination of geometrical translation of the position of the node, andchange of the material orientation. The analytical method is formulated based onhomogenization method together with finite element method, and fiber waviness isconsidered by using perturbation method. Fiber waviness is introduced as an input tothe calculation, and the calculation is always done using the idealized perfectgeometry, thanks to the utilization of perturbation method. This has a distinctadvantage in numerical calculations where the same mesh can be used for a series offiber waviness. The method is implemented using general-purpose finite element codeABAQUS. The proposed method is validated by comparing the results to those of aconventional calculation. The results demonstrate that the proposed method canaccurately capture the stress distribution when the amplitude of the imperfection issmall.