DescriptionStructural sandwich panels are commonly used in marine and aerospace applications. They are composed of a core and skins bonded together using polymer matrices. Polyvinyl chloride (PVC)/carbon sandwich beams having organic resins as adhesives are known for their high strength to weight ratio. One of the major concerns is their vulnerability to fire. The organic matrices not only deteriorate at temperatures above 300°C but also emit toxins.
The research presented in this dissertation deals with the development of PVC/carbon sandwich panels using an inorganic matrix. The matrix can sustain temperature up to 1000°C and emits no toxins.
The primary objective of the research presented in this dissertation was to evaluate the feasibility of the matrix for manufacturing sandwich panels. The evaluation was carried out by fabricating sandwich beams and testing them in flexure and high temperature fire exposure.
The variables investigated were: foam density, type and volume fraction of carbon fibers used for skins and extra insulation for fire protection. Strength, stiffness and high temperature resistance properties were measured.
For temperature resistance evaluation, Ohio State University test, the NBS test, and heated element exposure test were used. The results obtained show that inorganic polymer can be effectively used to fabricate fire resistant sandwich beams. The strength and stiffness properties of beams fabricated with inorganic polymer are about -3% and +14% of values obtained for organic polymer skins. The samples with inorganic polymer skin and 1 mm coating easily passed the Federal Aviation Administration (FAA) requirements for fire tests. When exposed to heating element, the beams can sustain 300°C for indefinite duration and 700°C for 5 minutes. Preliminary studies are also presented for an all inorganic sandwich beams that can sustain 1050°C. Analytical procedures are presented to estimate the moment capacities of the beams.