Simplified bead-chain model for direct fiber simulation in viscous flow

For efficient simulation of the motion of fibers during processing of fiber-reinforced thermoplastics, we propose a simplification of the bead-chain model (BCM), in which each fiber is modeled as a chain of spheres. The proposed simplified bead-chain model (SBCM) solves only one equation of translational motion, whereas the BCM requires three equations. The effects of bending and hydrodynamic torques, which are considered in the equation of rotational motion in the BCM, are expressed in the SBCM by adding terms to the equation of translational motion, although twisting motion is ignored. The validity of the SBCM is examined by comparing the results of both models when simulating the behavior of a single fiber and fiber suspensions in a simple shear flow. The SBCM provides results comparable to those of the BCM with lower computation time. This suggests that the SBCM could be an efficient alternative to the BCM.