Loss Energy of Composite Materials. Part II: Impact Loading

Abstract

Abstract This paper deals with the influence of material structure parameters (fiber treatment and content of micropores) on the impact behavior of composite materials. Furthermore, an impact falling-weight testing device and the characteristic impact values are introduced. The role of the fiber/matrix interphase was investigated by using glass and natural (jute) fibers with different treatments. To study the influence of the content of micropores, epoxy foam reinforced with glass fiber mats were prepared. All materials were impacted on an instrumented low-velocity non-penetration falling-weight impact tester. By integrating the measured force/deflection curves, all characteristic values were determined. Finally, the fatigue behavior of epoxy foam reinforced with pre-treated woven fabrics and the jute/PP laminates under repeated impact were investigated. In all impact experiments, the damping index responded more sensitively to changes in the material structure than did the loss energy. Furthermore, it was found that the damping index is an excellent measurement for characterizing the extent of damage.