STIR: Tailored Interfaces for High Strength Composites Across Strain Rates

Abstract

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. The objective of this STIR research effort was to study the influence of nanostructured interfaces in the interfacial behavior of polymer fiber reinforced composites such that lightweight materials can be designed for both structural and ballistic performance. To achieve this objective a nanostructured interface has been be grown on the fiber surface using a process recently developed by the PI. This process allows for growth at low temperature, which preserves the fiber strength and makes the growth compatible with polymer fibers. This is the first technique for ABSTRACTThe objective of this STIR research effort was to study the influence of nanostructured interfaces in the interfacial behavior of polymer fiber reinforced composites such that lightweight materials can be designed for both structural and ballistic performance. To achieve this objective a nanostructured interface has been be grown on the fiber surface using a process recently developed by the PI. This process allows for growth at low temperature, which preserves the fiber strength and makes the growth compatible with polymer fibers. This is the first technique for the growth of a reinforcing whisker or nanowire on polymer fibers. The nanowire growth process is highly controllable and acts to enhance the load transfer between the matrix and fiber while also providing out of plane reinforcement. The controllable nanowire growth offer a means for optimizing the interfacial properties such that an ideal material response can be obtained at both high and low strain rates. In addition to control of the nanowire morphology and load transfer, the adhesive bond between the brittle nanowires and the tough Kevlar fiber was varied such that under impact the interface releases the fiber to absorb the ballistic energy. (c) Presentations