HIGH STRAIN RATE TESTING OF CO-CURED/Z-PINNED COMPOSITES IN MODE-I Hakan Kilic, Rakesh Patel, and Som R. Soni AdTech Systems Research, Inc. 1342 N. Fairfield Road Beavercreek, OH 45432 hkilic@adtechsystems.com rpatel@adtechsystems.com srsoni@adtechsystems.com ABSTRACT A new test fixture was designed to enable the high strain rate testing of double cantilever beam (DCB) specimens and to improve high strain rate test techniques. Experimental and analytical investigations were performed on mode I high strain rate response of DCB specimens with and without (unreinforced) z-fibers. The new fixture enables to collect more reliable data for high strain rate response of composite materials in mode I. It can also be used for the high strain rate testing of end-notch-flexural (ENF) and T-section specimens. In addition to the high strain rate tests, static tests were also carried out to compare the high strain rate results with the controlled static test data. The proposed high strain rate testing methodology along with the newly developed high strain rate test fixture has yielded promising results. KEYWORDS: Delamination/Delamination Resistance, Impact Damage/Resistance/Behavior, Testing/Evaluation 1. INTRODUCTION The use of polymer matrix composites and co-cured assemblies in airframe structures has shown promise in achieving the performance and cost goals of next generation fighter/attack aircraft. The weight and/or affordability benefits may be limited however by the need to meet survivability requirements. The current survivable design procedure is to size a structure for flight, fuel pressure, crash, etc. loads and then ballistically test the resulting design to determine its survivability capability. For metal structures, this remains a feasible process since there are plenty of historical ballistic test data available for use in developing design requirements. However, this is not the case for composite structures.