"Fun With Funny Materials"
Dan Inman, Department of Mechanical Engineering, Virginia Tech
Smart materials enable unique solutions to many aerospace and mechanical related problems. Here we examine a several interesting problems that can be solved using piezoelectric devices: morphing wings, energy harvesting and structural health monitoring. These disciplines involve combining mechanical fields with electrical fields though the piezoelectric constitutive laws. Morphing as used here refers to the use of shape change as alternative discrete control surfaces for flight control of small-unmanned air vehicles. The use of piezoceramic based macro fiber composite materials to control wing chamber in a small radio controlled, all electric aircraft is examined. The solution revolves around a choice of electronics and structural properties. Structural health monitoring (SHM) affords the ability to examine structures for faults while they are in service. The need to integrate SHM into in service demands that the devices be wireless that in turn leads to the need for low power sensing, actuation and computing. A primitive but successful method of using piezoceramics to interrogate various structures using levels of energy that are compatible with harvested energy will be presented. An overview of our efforts to harvest ambient waste energy to run the sensors is presented. Next the two concepts of harvesting and monitoring are combined to form a wireless monitoring system. In addition, an application of using shape memory alloys to illustrate a self-healing system is presented.
Daniel J. Inman received his Ph.D. from Michigan State University in Mechanical Engineering in 1980 and is the Director of the Center for Intelligent Material Systems and Structures, the Director of the Center for Energy Harvesting Materials and Structures, and the G.R. Goodson Professor in the Department of Mechanical Engineering at Virginia Tech and the Brunel Professor of Smart Technologies at the University of Bristol, UK. Since 1980, he has published six books (on vibration, control, statics, and dynamics), eight software manuals, 20 book chapters, over 250 journal papers and 490 proceedings papers, given 45 keynote or plenary lectures, graduated 49 Ph.D. students and supervised more than 75 MS degrees. He works in the area of applying smart structures to solve engineering problems including energy harvesting, structural health monitoring, vibration suppression and morphing. He is a Fellow of ASME, AIAA, IIAV and AAM.