584. The Potential of Advanced Fibrous Reinforced Composite Materials for Structural Applications

Paper

Abstract

With the advent of high strength, high modulus reinforcements, structural composites offer the potential for a major breakthrough in aerospace vehicle design. Boron fiber reinforced epoxy composites, for example, have demonstrated a modulus of 35 x 10^6 psi, a tensile strength in excess of 200,000 psi, and a density of 0.072 $#$/in^3 for the unidirectional orientation. These composite properties are attractive to the structural designer, however because properties are largely dependent upon the fiber, then fiber orientation becomes an important variable. Once the flexibility of fiber orientation is introduced, the designer becomes aware of a new dimension, anisotropy.
The prime structural design parameters for aerospace vehicles are strength and stiffness. Orientation of the fibers in the directions of major load essentially ‘inputs the material where it is required.’ This facet of high modulus, high strength fiber reinforced composites results in weight savings of 20 to 30% for the majority of the structure.