The Role of Bond Strength in the Fracture of Advanced Filament Reinforced Composites

Abstract

A great number of studies have been made to establish the longitudinal strength characteristics of composites, with success being measured in many instances by the degree to which “rule of mixtures” predictions have been attained. Several investigators report good agreement for modulus and tensile strength in metallic filament reinforced composites. Agreement for strength predictions is less frequent in systems using continuous and discontinuous nonmetallic filament arrays. This lack of ability to predict strength of uniaxially reinforced specimens points up the need for further research on the factors contributing to premature and sometimes catastrophic failure of filament reinforced specimens. As a result of using single and multiple filament specimens of boron in epoxy novolac, methods for localizing the damage resulting from individual filament fractures were developed. Optimization of the bonding mechanism is one area of research which has yielded some very interesting results. Contrary to the concept that bond strength should be as high as possible, these studies show that, although a good bond is essential to the reinforcing mechanism, too high a bond strength may render the composite severely matrix limited. Further, it has been demonstrated in this work that varying the nature of the bond surface can be most effective in isolating the sudden energy release at a filament fracture.

A Comprehensive Model for Determining Tensile Strengths of Various Unidirectional Composites

“…On the right side of the point, the fibers fail simultaneously, and the composite fails in a brittle manner. The SFF can lead exactly similar relationships between the composite strength and interfacial strength to those of experimental [12,13,24] and analytical results [12,14,15] in the existing articles.…”

Incorporation of Graphene Nanoplatelets into Fiber-Reinforced Polymer Composites in the Presence of Highly Branched Waterborne Polyurethanes

“…Achieving an optimal level of interfacial interaction is imperative for maximizing the performance and mechanical properties of CFRPCs. As a result, the stress concentration tends to be higher around these breakages [ 5 , 6 , 7 ]. The load-carrying capacity of composite materials hinges predominantly on the nature of the fiber–matrix bonding, encompassing both chemical and frictional interactions [ 8 , 9 ].…”

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