Q – Competition oversees? A – He argued that American programs are certainly ahead. However, Kudva said, the Chinese are trying to break into NextGen’s servers on a frequent basis, and there has been an explosion of patent applications from oversees.

ADAPTIVE STRUCTURES TECHNOLOGY FOR ADVANCED AIRCRAFT

Ed White, Adaptive Structures Technology Focus Team Leader, Associate Technical Fellow, Boeing Research and Technology.

Mr. White’s talk on adaptive structures technology for advanced aircraft began by his discussing what is stopping adaptive airframes. He believes that solutions based on kinematics of rigid structures are usually too heavy and introduce concerns with added complexity, reliability, and maintainability. He then discussed the barriers that adaptive airframes have at the platform performance level. These include limited ability to do multidisciplinary analysis and optimization (MDAO) with adaptive airframe elements. Mr. White noted that researchers can create point designs for adaptive airframe solutions, but not within an MDAO environment, but he felt that this will need to change in the future.

Mr. White presented three key technology developments that are needed. These developments included compact, highly weight efficient variable geometry primary load paths; skins to provide fairings and gap closeouts to support the variable geometry; and highly integrated, multi-degree-of-semi freedom actuators. Next White discussed key implementation indicators. Some of these indicators included large-scale testing of any of the technology needs area previously mentioned, and testing beyond a technology readiness level of 6.

To summarize, White suggested that adaptive structures (applied to large structures) require technology development in the three key technology development areas. He also believes that design of adaptive airframes must be performed as part of a system level trade off and that the development of these tools lag significantly behind the current research on adaptive structural materials.

MAGNETIC SHAPE MEMORY

Manfred Wuttig, Professor, and Director of Graduate Program, Department of Materials Science and Engineering, University of Maryland.

Professor Wuttig noted that shape memory alloys are a general class of materials that remember their original shape. They are potentially useful in actuators that may be designed to change shape, stiffness, position, natural frequency of vibration, and other mechanical characteristics in response to temperature or electromagnetic fields. He stated that magnetic shape memory alloys are ferromagnetic materials that exhibit tensile strain (with a measurable relative physical extension that can be as large as 10%) when a magnetic field is imposed on the material. The physical extension depends on the magnetic anisotropy of the material, where the magnetic domains line up much more readily in one direction than in the other. The main advantage of magnetic shape memory alloys over conventional shape memory alloys, he argued, is that the former can respond faster to changes than the latter. Magnetic field effects operate on a faster time scale than thermal effects.

Dr. Wuttig noted that the leading foreign research work in magnetic shape memory alloys is being carried out primarily in Europe (University of Helsinki, University of Dresden, and University of Barcelona), Russia (Kiev University), and Asia (Tohoku University and Tsing-Hua University). In the United States, he said, this kind of work is being carried out at Caltech, MIT, and the University of Maryland.

Dr. Wuttig stated that most of the work in this area is still in its infancy. The synthesis of ferromagnetic materials for dynamic adaptive applications is still a challenge. The unit volumetric change for applied input energy remains too high. Use of magnetic shape memory alloys in large



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