Virtual Vibration Testing of External Stores Navy SBIR FY2010.1 Sol No.: Navy SBIR FY2010.1 Topic No.: N101-015 Topic Title: Virtual Vibration Testing of External Stores Proposal No.: N101-015-2098 Firm: NextGen Aeronautics 2780 Skypark Drive Suite 400 Torrance, California 90505 Contact: Gerald Andersen Phone: (310) 626-8373 Web Site: www.nextgenaero.com Abstract: The difficulty in developing system identification and synthesis methodologies that are valid for broad classes of dynamical systems is due to the well-recognized highly individualistic nature of nonlinear systems which restricts the unifying dynamical features that are amenable to this process. Our proposed technique relies solely on direct time series measurement and post processing, and leads to global as well as local identification of a broad class of dynamical systems. Key to our method is the slow/fast partition of time series measurements which leads to the identification of the dominant fast frequencies in the measured time series (which ultimately govern the dimensionality of the dynamics), to identification of global features of the dynamics in the frequency - energy domain, and to reduced slow flow models. We employ advanced post processing computational algorithms, namely, wavelet transform (WT), Hilbert transform (HT) and empirical mode decomposition (EMD) unified by a solid theoretical framework. Our technique successfully integrates analytical concepts and computational algorithms in a synergistic methodology. Benefits: Limitations concerning vibration analysis of aircraft external stores prevent accurate simulation of the complex interactions from multiple load paths, load input, distributed boundary conditions, and multiple forms of highly nonlinear behavior. The development of a method that innately considers these effects will allow substantial benefits to aircraft structural analysis, including more accurate analytic results which more closely match ground vibration test results. As confidence in the new analysis method is gained, cost savings will be realized as ground vibration testing and even flight testing will be reduced, leading to cost and time savings in the airframe development process. Return