Flexural Response of Inorganic Hybrid Composites With E-Glass and Carbon Fibers

Abstract

By far, carbon and glass fibers are the most popular fiber reinforcements for composites. Traditional carbon composites are relatively expensive since the manufacturing process requires significant heat and pressure, while the carbon fibers themselves are inherently expensive to produce. In addition, they are often flammable and their use is restricted when fire is a critical design parameter. Glass fabrics are approximately one order of magnitude less expensive than similar carbon fabrics. However, they lack the stiffness and the durability needed for many high performance applications. By combining these two types of fibers, hybrid composites can be fabricated that are strong, yet relatively inexpensive to produce. The primary objective of this study was to experimentally investigate the effects of bonding high strength carbon fibers to E-glass composite cores using a high temperature, inorganic matrix known as geopolymer. Carbon fibers were bonded to E-glass cores (i) on only the tension face, (ii) on both the tension and compression faces, or (iii) dispersed throughout the core in alternating layers to obtain a strong, yet economical, hybrid composite laminate. For each response measured (flexural capacity, stiffness, and ductility), at least one hybrid configuration displayed mechanical properties comparable to all carbon composite laminates. The results indicate that hybrid composite plates manufactured using 3k unidirectional carbon tape exhibit increases in flexural capacity of approximately 700% over those manufactured using E-glass fibers alone. In general, as the relative amount of carbon fibers increased, the likelihood of precipitating a compression failure also increased. For 92% of the specimens tested, the threshold for obtaining a compression failure was utilizing 30% carbon fibers. The results presented herein can dictate future studies to optimize hybrid performance and to achieve economical configurations for a given set of design requirements.

Fibre hybridisation in polymer composites: A review

“…Similarly, Giancaspro et al [91] noticed that glass fibre composites failed on the tension side, while carbon fibre composites failed mainly on the compression side. Adding carbon fibres on the tension side of glass fibre composites increased the flexural strength, while this was not the case when they were added on the compressive side.…”

“…According to Giancaspro et al [91] and Dong et al [93], an optimal level of glass fibre exists to achieve maximum flexural strength. Dong et al [93] stated that the highest flexural strength in carbon/glass hybrids was achieved at a relative content of 12.5% of glass fibres, all of which are placed on the compressive side.…”

“…As is clear from Table 3, no clear conclusion on the influence of positioning of the layers in asymmetric hybrid composites on the penetration impact resistance has been reached in literature. [95] 1999 Carbon/glass improved deteriorated Naik et al [94] 2001 Carbon/glass / deteriorated deteriorated Sevkat et al [91] 2009 Carbon/glass improved deteriorated Sevkat et al [5] 2010 Carbon/glass improved Enfedaque et al [90] 2010 Carbon/glass improved González et al [151] 2014 Carbon/glass improved no effect Table 3: Overview of how penetration impact resistance is affected by putting the LE fibre closer to the impact side in asymmetric layups.…”

A Novel MK-based Geopolymer Composite Activated with Rice Husk Ash and KOH: Performance at High Temperature

“…Zhang et al (60) found that for geopolymer with addition of 2% milled carbon fibre this volume to provide effective control of cracking to 500 °C and the fibers do not significantly influence the resistance at high temperature (700 °C). However, flexural strength (41). This is may be because the geopolymer is sintered at 1200 °C, porosity is reduced, crystalline phases such as leucite and mullite are formed, and the particles obstruct the advance of the cracks, aiding in the compaction of the material.…”

“…By bridging cracks, a wide range of polymeric, mineral and natural fibres have been used to improve geopolymer tensile and flexural strength, toughness, and energy absorption capacities (35). Short fibres of polypropylene (PP) (36,37), polyvinyl alcohol (PVA) (38), basalt (39,40), glass (41,42), carbon (43,44), alumina (45,46) and steel (47) have been successfully incorporated into geopolymers at volume fractions between 0.5-3.5%. Higher fibre contents, up to 20% (44), provide more control over cracking and increase mechanical strength of the brittle matrix.…”