1. 66 -0.132041e-f6
2. Fig. 5-11:Graphite-epoxy beam with SMA wires.
3. Magnetostrictive effect was discovered first in nickel by James Joule in 1840.Later on, cobalt, iron and their alloys were shown to have significant magnetostrictive effects likeNickel.The maximum strains were of the order of 50 ppm (parts per million,005%). Arthur Clark and his research group at Naval Ordnance Lab (now NSWC) discovered Terfenol-D in early 1970s that produced a significantly larger magnetostriction resulting in a maximum strain of the order 2000 ppm. This is almost twice the maximum strain produced bypiezoceramics. The strains and forces produced by Terfenol-D are more than those available with piezoelectric and electrostrictive materials. Magnetostrctive find applications in machine tools, servo-valves, hybrid motors, sonar and tomography, automotive brake systems, micro-positioners and particulate-actuators and sensors. As a result of Joule effect, an application of magnetic field results in longitudinal extensional strain accompanied by transverse compressive strain. The reciprocal effect is called Villari effect where an application of stress (i.e., strain) results in achangein its magneticfield. The Joule effect is used in actuators whereas the Villari effect is used in sensors. The manufacturing of Terfenol-D is carried out by melting the material, and then casting and directionally solidifying to provide the crystalline microstructure needed to producelargestrains.13(33 -800 -S00-*4e3-200 E00 400
4. No. MM8M(70018) MM5H (70023-1) MM45(70023-2)