Experimental investigation of dynamic mechanical properties of polyurea-fly ash composites

Abstract

Polyurea has been the material of choice in many applications due to its thermomechanical properties. These applications span a wide spectrum from abrasion-resistant coating to reinforcement against blast damage in structures, ships, and vehicles. The improved observed performance is linked to its microstructure, a lightly crosslinked (elastomeric) block copolymer. The constitutive modeling of such materials is generally based on a wide variety of experimental measurements, including dynamic mechanical analysis. Furthermore, the response under stress-wave propagation may be measured through ultrasonic tests. In this work we present our research towards improvement and modification of the dynamic mechanical properties of polyurea through inclusion of various size and distributions of fly ash hollow spherical particles. The extensive experimental results are reported and a micromechanical homogenization model is presented. The extent of application of such model will be established and alternative modeling techniques which include the possible inertia effects at high rates of deformation will be surveyed.