THE DESIGN OF A HYBRID MATERIAL FOR MULTIFUNCTIONAL PERFORMANCE USING ADVANCED ANALYSIS TECHNIQUES AND TESTING

摘要

The design requirements for primary aircraft structure are diverse in nature, including properties related to buckling, bearing, compression, and tension, together with properties such as damagetolerance and damage-resistance. A multifunctional approach to design would strike a balance between all these requirements, or functions in order to produce an optimal design. The design of an aerospace structure using an off-the-shelf composite would involve increasing the gage thickness until all of the design requirements are met. This can lead to an inefficient design, because excess margins will exist for all properties except the one that determines the gauge. The design of a material can be made practical by creating a hybrid composite comprised of two or more types of fibers or resins, each embellishing a particular trait or function to the material. This paper investigates the impact of hail against a toughened-epoxy, intermediate-modulus, carbon-fiber composite using both experimental and analytical means. The effect of introducing ply-level hybridization by substituting up to 20 percent of the plies with glass-reinforced plies is considered. It is found that delamination can in many cases be reduced by this hybridization, but the benefits are dependent on the impact energy and the test conditions. A computational model based on the peridynamic theory of solid mechanics is used to understand the benefits and tradeoffs in hybridization.