Speed of sound and ballistic resistance of nanocomposite films

Abstract We present a numerical model for the factors controlling the velocity of sound and ballistic performance of nanocomposite polymer films. In our approach, the composite material is represented by a three‐dimensional lattice of bonds having different mass and elastic constants for the inclusion and for the matrix. The mechanics of impact wave propagation is formulated in terms of impulse‐momentum balance equations which are solved at each lattice site using a finite difference technique. Our study indicates that the efficiency of load transfer across a composite film is negatively impacted by the mismatch in impedance between matrix and inclusions. We also find that, among all inclusions, platelets with high aspect ratio are the most promising. They clearly lead to a faster sound velocity, wider propagation of the impact wave and higher critical perforation velocity V50. POLYM. COMPOS. 2012. © 2012 Society of Plastics Engineers