Abstract

Braided quasi-isotropic (0°, +/-60°) fabric has enabled easy lay-up and provided superior performance for a variety of composite applications, but to date the test data characterizing the benefits of quasi-isotropic fabric has been application specific. Quasi-isotropic laminates composed of prepregged woven fabric were compared to laminates composed of prepregged quasi-isotropic braided fabric. Both fabrics were produced with the same fiber type and were prepregged with the same resin. The coupon test matrix included: tension and compression in multiple directions; in-plane shear; CAI; open-hole tension and open-hole compression. Panel testing included impact testing using a soft gelatin projectile. The panel testing performed bracketed the containment threshold. Analysis of the two material systems studied and the impact testing performed will be examined, for the first time, in this presentation.

Abstract

The National Research Council of Canada - Herzberg Institute of Astrophysics' (HIA) Dominion Radio Astrophysical Observatory (DRAO) won a JEC Award 2009 in Paris for the "Composite Applications for Radio Telescopes" (CART) project, together with its partner Profile Composites Inc. from Sidney, BC, Canada. Profile Composites chose a hybridized form of A&P Technology's QISO® braided triaxial fabric for the development of its composite tooling, which is ultimately intended for large radio antennae applications. This antennae is about 12 - 15 metres in diameter and requires quasi-isotropic properties over a large, curved surface where dimensional control and heat transfer are critical. The properties that make A&P Technology's QISO® an excellent choice for the fabrication of advanced composite parts in the aerospace, recreation and infrastructure markets, make it an equally superior choice for composite tooling applications.

Abstract

Triaxial braid composite materials are beginning to be used in fan cases for commercial gas turbine engines. The primary benefit for the use of composite materials is reduced weight and the associated reduction in fuel consumption. However, there are also cost benefits in some applications. This paper presents a description of the braided composite materials and discusses aspects of the braiding process that can be utilized for efficient fabrication of composite cases. The paper also presents an approach that was developed for evaluating the braided composite materials and composite fan cases in a ballistic impact laboratory. Impact of composite panels with a soft projectile is used for materials evaluation. Impact of composite fan cases with fan blades or blade-like projectiles is used to evaluate containment capability. A post-impact structural load test is used to evaluate the capability of the impacted fan case to survive dynamic loads during engine spool down. Validation of these new test methods is demonstrated by comparison with results of engine blade-out tests.

Abstract

Until now, the automated material processes used to manufacture large, composite aerospace structures have been filament winding, automated tape layup, and fiber placement. An overview of the advancements in braided preform architectures and braiding machinery identify braiding as an attractive process alternative for composite manufacturers. State-of-the-art braiding equipment incorporates fully automated control over all braiding parameters, including translational and rotational control of the mandrel, a vision system for real-time inspection, a laser projection system and integrated circumferential winding. These technological advancements, in addition to the high rate of material deposition found with braiding approach the precision demonstrated by fiber placement systems and the cost efficiency found in filament winding and is applicable to the manufacture of large scale, structural preforms.