  In this paper, a fundamental understanding of the densification mechanics of
syntactic foams under compressive loading is established. Syntactic foams are
closed cell composite foams with thin-walled microballoons dispersed in a
matrix (resin) whose closed cell structure provides excellent mechanical
properties, like high strength and low density. There are several parameters
that can contribute towards the mechanical properties, including, microballoon
volume fraction, microballoon wall thickness, bonding between the microballoons
and the matrix, and the crushing strength of microballoons. Conducting purely
experimental testing by varying these parameters can be very time sensitive and
expensive. Also, identification of densification mechanics is challenging using
experiments only. Higher densification stress and energy are favorable
properties under foam compression or crushing. Hence, the influence of key
structural and material parameters associated with syntactic foams that dictate
the mechanics of densification is studied here by implementing micromechanics
based computational models and multiple linear regression analysis. In
particular, specific densification stresses and energy, which are densification
stresses and energy normalized by weight, are evaluated which are more relevant
for a wide variety of weight saving applications. GMB crushing strength and
volume fraction are identified as the parameters that have the most significant
impact on densification stress and energy, and their specific counterparts.
