Finite element based energy dissipation studies of Al-SiC composites

In the present study, the damping capacity of Al-SiC composite formulations is predicted using a visco-plasticity based micro-mechanical modelling approach. The model is based on finite element analysis of an axisymmetric unit cell, which mimics a pure Al cylinder with a spherical SiC reinforcing particulate placed at the centre. The energy dissipated by the composite is numerically predicted using the unit cell by applying a harmonic load, taking into account the viscous behavior of the processing induced residual plastic strain at the matrix-reinforcement interface of the composite. The model shows that the plastic zone size increases with volume fraction of SiC added resulting in a proportional increase in damping capacity of the composite. The model was validated by comparing the numerical results against an impact based suspended beam experiment conducted at low strain amplitude on Al-SiC samples with different volume fraction of SiC particulates. In addition, an attempt has been made to study the effect of particulates' stress concentration features as well as process-induced defects on the overall damping capacity of the composite.