Damping capacity of syntactic foams

Hollow particle filled composites are studied for their damping characteristics under low-frequency mechanical vibrations. Vibration damping capabilities are desirable in marine applications to enhance the structural stability under continuous and repetitive loading of waves. The elastic properties of an infinitely dilute dispersion of microballoons (hollow particles) in a matrix material are first computed by solving a dilatation and a shear problem. Using the elasticityviscoelasticity correspondence principle, the viscoelastic properties of the syntactic foam are determined in terms of microballoons. wall thickness and volume fractions. A differential scheme is then used to extrapolate the elastic properties of composites containing high volume fractions of microballoons. Vinyl ester resin matrix composites filled with glass microballoons are synthesized and tested using an in-house developed optic-based vibration testing equipment. Theoretical predictions are in good agreement with experimental findings. Results show that the damping capacity and the elastic stiffness of composites can be optimized by a combination of particles. concentration and wall-thickness.