Tailored material properties using textile composites

Abstract

Lightweighting is essential for the reduction of energy consumption in transportation. The most common approach is through the application of high specific strength and stiffness materials, such as composites and high performance aluminum alloys. One of the challenges associated with the use of advanced materials is the high cost. This paper explores the opportunities of using hybrid composites (glass and carbon, for example) with selective fiber placement to optimize the weight subject to price constraints for given components. Considering the example of a hat-section for hood reinforcement, different material configurations were modeled and developed. The required thickness of the hat section to meet the same bending stiffness as an all carbon composite beam was calculated. It was shown that selective placement of fiber around the highest moments results in a weight savings of around 14% compared to a uniformly blended hybrid with the same total material configuration. From this it is possible to estimate the materials cost of the configurations as well as the weight of the component. To determine which is best it is necessary to find an exchange constant that converts weight into cost - the penalty of carrying the extra weight. The value of this exchange constant will depend on the particular application.