NASA has been a leader in development of composite materials for aircraft applications during the past 25 years. In the early 1980’s NASA and others conducted research to improve damage tolerance of composite structures through the use of toughened resins but these resins were not costeffective. The aircraft industry wanted affordable, robust structures that could withstand the rigors of flight...

A novel method of manufacturing rigid and robust natural fiber preforms is presented here. This method is based on a papermaking process, whereby loose and short sisal fibers are dispersed into a water suspension containing bacterial cellulose. The fiber and nanocellulose suspension is then filtered (using vacuum or gravity) and the wet filter cake pressed to squeeze out any excess water, follo...

In recent years, large composite structures have been used increasingly in the aerospace and naval industries. Such a large composite structure is mostly fabricated using the scarf joining technique so that multiple substructures can be connected together. Figure 1 shows three commonly used scarf joint configuration. Among the three, the step/overlap joint is considered as the strongest because...

Although aramid fiber has the advantage of excellent chemical and mechanical properties, performance composites may be reduced due to low interfacial adhesion between fabric matrix. The surface was modified improve properties. fibers treated with ZnCl2 polydopamine. After pretreated fabrics were made into a composite material by vacuum-assisted resin transfer molding (VARTM) process, their inve...

Room temperature cure epoxy resin has been doped with SiC nanoparticles through an ultrasonic cavitation process. The modified resin was then utilized in a Vacuum Assisted Resin Transfer Molding (VARTM) process with satin weave carbon fibers to manufacture nanophased composite panels. The nanoparticles were spherical in shape and about 29 nm in diameter. The loading of nanoparticles into the re...

Despite significant advancements in bio-based natural-fiber-reinforced composites, the recyclability/reprocessing of thermoset composites remains a persistent challenge that needs to be addressed. In present study, an effort is made provide justification for assessment sandwich composite panels with ‘recyclate’ (i.e., recycled flax/bio-based epoxy composite) cores and (flax/bio-based epoxy) ski...

Abstract In this study, the mechanical properties of plain woven jute-epoxy composite materials were investigated after filling graphene nanoplatelets (GNPs) in different proportions. The time dependent changes viscosity and temperature unfilled epoxy resin, with 0.5, 1 2 wt.-% filled resins observed. Woven jute reinforced unfilled, 0.5 GNPs plates produced by using vacuum assisted resin transf...

Fill-front and cure progress monitoring is critical for vacuum-assisted resin transfer molding (VARTM) manufacturing processes. The experimental multi-channel system presented in this paper includes sensors, signal conditioning, data acquisition software, and signal post-processing components. The sensors are mechanically flexible and optically transparent fringing electric field electrode syst...