A Microscopic Experimental Investigation of Failure Mechanisms in a Triaxially Braided Polymer Composite

Abstract

A microscopic experimental investigation was conducted to track the development of damage leading to failure during tensile static and fatigue loading of a triaxially braided polymeric composite material. Edge replication and scanning electron microscopy were employed to track damage development and to identify existing damage mechanisms, respectively. The results indicate that cracking in the braider yarns is the dominant damage mechanism during static and fatigue loading. The development of damage throughout loading and during the final damage state prior to failure is however markedly different for static and fatigue loaded test specimens. This was confirmed by observation of the fracture surfaces as well as post mortem microscopy. The results provided a better understanding of the damage development, local deformation behaviour and the corresponding failure mechanisms for the braided material during static and fatigue load