This award provides partial support for a long term visit by Professor John Lamancusa of Pennsylvania State University to the University of Siegen, Germany, where he will collaborate with Professor Hans Eschenauer of the Research Laboratory for Structural Optimization. The objective of their research is to develop methods and computational tools for designing quiet mechanical structures constructed of advanced composite materials. Dr. Lamancusa and his research group bring to the collaboration expertise in the fields of acoustic propagation, prediction and structural vibrations. This is complemented by the German group's multidisciplinary expertise in optimization. They have developed innovative methods for shape optimization of large, composite structures with static and dynamic performance criteria. The long term cooperative research visit by Dr. Lamancusa will facilitate a sharing of expertise in structural acoustics and the science of optimization between two of the premier international institutions in those fields. Recent advances in structural and acoustic analysis techniques now make it possible to predict the acoustic performance of complicated structures before fabrication. Meanwhile, improved computing resources and optimization methods have made structural optimization feasible for complex structures with many variables. These techniques have not been applied yet to the acoustical design of structures of non-traditional materials. This project will address the feasibility and special problems inherent in the optimal design of composite material structures for acoustical performance.