Wednesday, February 14, 2007, 11pm - 12pm, MDEA

ADVANCES IN EXPERIMENTAL MECHANICS FOR SMART MATERIALS 
 

Albert S. Kobayashi

University of Washington

Department of Mechanical Engineering

Seattle, Washington 98195, USA

Literature is sparse on experimental techniques specifically developed for smart materials.  Much of the smart material research is concentrated on the material characterization of a shape memory alloy (SMA) of Nitinol.  In view of the evolving state of smart material, this review will be presented in the broad categories of modeling, Nitinol and novel experimental techniques.  The much of the present review was abstracted from Experimental Mechanics, April, 2006 and the Proceedings of the 2005 and 2006 SEM Annual Conferences. 

Modeling papers include those by J. Abanto-Bueno and J. Lambos, N. Jain and A. Shukla and by M.S. Kirugulige and H.V. Tippur.  All three papers describe novel techniques for fabricating functionally graded material (FGM) for studying mixed-mode static or dynamic crack propagation.  Thermoelastic transformations and the localization effect of the strain field in the parent and transformed phase in Nitinol was studied by K. Perry, P.E. Labossiere, E. Steffler, N. Stevens and W.R. Lloyd with phase-shifted moiré interferometry.  S. Nemat-Nasser, J.Y. Choi, J.B. Isaacs and M.R. Aminire reported on the super-elastic response of a buckled Nitinol thin shell due to axial compression under static and dynamic loading and unloading cycle.  S. Song, Y.L. Mo, K. Otero and H. Gu developed an intelligent reinforced concrete structure (IRCS) with NiTi and PZT piezo-ceramics where the SMA cables were heated electrically to close cracks in the concrete structure and embedded PZT patches were used to detect possible cracks.  J.A. Balta, F. Bosia, V. Michaud, G. Dunkel, J. Botsis and J-A Månson used fiber Bragg grating sensors for a strain stabilizing feedback mechanism in a Nitinol epoxy composite.  Novel Experimental Techniques include the high precision displacement sensor coupled with a transparent spherical indenter by C. Feng and B.S. Kang to obtain accurate load-depth curve, unloading stiffness data and the local Young’s modulus.   S. Chang, F.-P. Chiang and A.H. Rosenberger used speckle interferometry with electron microscopy to determine the local modulus of elasticity in fine grained TiAl specimens.